2016-05-06
James Slattery
James Slattery5:35 PM

@James Slattery has joined the channel

2016-06-14
James Slattery
James Slattery12:45 PM

@James Slattery set the channel purpose: All things mechanics.

Clio Batali
Clio Batali10:10 PM

@Clio Batali has joined the channel

2016-06-22
Will Hobbs
Will Hobbs7:33 PM

@Will Hobbs has joined the channel

Alex Larson Freeman
Alex Larson Freeman7:34 PM

@Alex Larson Freeman has joined the channel

2016-07-09
2016-07-13
Lucas Rininger
Lucas Rininger10:29 PM

@Lucas Rininger has joined the channel

2016-07-18
Jon Coonan
Jon Coonan2:45 PM

@Jon Coonan has joined the channel

2016-08-16
Alex Larson Freeman
Alex Larson Freeman10:33 AM

practicing some cad right now, how far should we drop the middle wheel on the chassis?

Alex Larson Freeman
Alex Larson Freeman10:33 AM

@Alex Larson Freeman set the channel topic: T-shirt Cannon Robot

Will Hobbs
Will Hobbs10:34 AM

I would drop it about a half an inch

Alex Larson Freeman
Alex Larson Freeman10:34 AM

alright.

Will Hobbs
Will Hobbs10:34 AM

Also can you move the gearbox to the rear of the chassis

Alex Larson Freeman
Alex Larson Freeman10:35 AM

I'll try. Shouldn't be too bad

Will Hobbs
Will Hobbs10:36 AM

Just look at how I did it the first time

Alex Larson Freeman
Alex Larson Freeman10:36 AM

Yeah I just need to do it without breaking everything

Alex Larson Freeman
Alex Larson Freeman11:03 AM

quick question

Alex Larson Freeman
Alex Larson Freeman11:03 AM

how do you break a joint between the chassis and other parts

Will Hobbs
Will Hobbs11:03 AM

Open the joint tab on the left side of the screen.

Will Hobbs
Will Hobbs11:04 AM

Then find the joint you want to get rid of and delete it

Will Hobbs
Will Hobbs11:04 AM

When you hover over the joints in the tab it will be highlighted on the model

Alex Larson Freeman
Alex Larson Freeman11:06 AM

ah

Alex Larson Freeman
Alex Larson Freeman11:06 AM

thanks

Alex Larson Freeman
Alex Larson Freeman11:06 AM

is there a way to just move stuff without deleting the joints?

Will Hobbs
Will Hobbs11:07 AM

If you right click the part and then select move you should be able to move the part regardless of any joints

Alex Larson Freeman
Alex Larson Freeman11:08 AM

When I tried that it moved the whole model

Will Hobbs
Will Hobbs11:09 AM

Then you have to delete the joint that attaches the part to the chassis

Will Hobbs
Will Hobbs11:09 AM

I am assuming you are trying to move the wheel down

Will Hobbs
Will Hobbs11:10 AM

If you are then you need to delete the joint that attaches the wheel and gearbox to the chassis

Alex Larson Freeman
Alex Larson Freeman11:10 AM

I'm trying to move the gearbox to the back

Alex Larson Freeman
Alex Larson Freeman11:11 AM

the problem is, it's hard to tell which joints hold the parts together and which ones attach it to the chassis

Will Hobbs
Will Hobbs11:11 AM

Ok let me take a look

Will Hobbs
Will Hobbs11:12 AM

How's your new computer

Alex Larson Freeman
Alex Larson Freeman11:14 AM

pretty good

Alex Larson Freeman
Alex Larson Freeman11:14 AM

actually I may have it now

Will Hobbs
Will Hobbs11:15 AM

Ok

Alex Larson Freeman
Alex Larson Freeman11:15 AM

I detached the gearbox + wheel thing

Alex Larson Freeman
Alex Larson Freeman11:15 AM

but feel free to look :stuckouttongue:

Will Hobbs
Will Hobbs11:16 AM

I will if I can get fusion to open

Alex Larson Freeman
Alex Larson Freeman11:17 AM

rip

Alex Larson Freeman
Alex Larson Freeman11:17 AM

actually the non-gearbox wheels are made up of 3 parts which is a but annoying

Alex Larson Freeman
Alex Larson Freeman11:17 AM

I may have to joint them

Alex Larson Freeman
Alex Larson Freeman11:17 AM

to make moving them easier

Will Hobbs
Will Hobbs11:18 AM

If you highlight all 3 parts you can select an as build joint

Alex Larson Freeman
Alex Larson Freeman11:19 AM

wait you can select multiple parts? nice

Alex Larson Freeman
Alex Larson Freeman11:22 AM

YES

Alex Larson Freeman
Alex Larson Freeman11:22 AM

it's working

Alex Larson Freeman
Alex Larson Freeman11:22 AM

I figured it out

Will Hobbs
Will Hobbs11:22 AM

Ok good

Will Hobbs
Will Hobbs11:23 AM

Fusion still won't open for me

Alex Larson Freeman
Alex Larson Freeman11:23 AM

took long enough

Alex Larson Freeman
Alex Larson Freeman11:23 AM

aw rip

Alex Larson Freeman
Alex Larson Freeman11:23 AM

restart maybe?

Will Hobbs
Will Hobbs11:23 AM

Yeah I will if it doesn't open soon

Will Hobbs
Will Hobbs11:24 AM

It worked when I first turned in my computer and then I closed it because it wasn't updating and now it won't open again

Alex Larson Freeman
Alex Larson Freeman11:24 AM

dang

Alex Larson Freeman
Alex Larson Freeman11:24 AM

I think that's worth a restart

Will Hobbs
Will Hobbs11:24 AM

Yeah

Alex Larson Freeman
Alex Larson Freeman11:24 AM

it's probably stuck in the update cycle or somethign

Alex Larson Freeman
Alex Larson Freeman11:34 AM

how far do you want the wheel dropped again?

Will Hobbs
Will Hobbs11:35 AM

1/2 an inch

Alex Larson Freeman
Alex Larson Freeman11:35 AM

alright

Alex Larson Freeman
Alex Larson Freeman12:08 PM

Sculpting stuff for the chassis pieces is beyond me

Alex Larson Freeman
Alex Larson Freeman12:09 PM

I moved the gearboxes to the back tho

Will Hobbs
Will Hobbs12:09 PM

Ok cool

Alex Larson Freeman
Alex Larson Freeman12:09 PM

I'm also messing with the electronics plate

Will Hobbs
Will Hobbs12:09 PM

Did you move the wheel down?

Alex Larson Freeman
Alex Larson Freeman12:09 PM

no

Alex Larson Freeman
Alex Larson Freeman12:09 PM

it requires the hole to be lowered

Alex Larson Freeman
Alex Larson Freeman12:10 PM

and that is some weird sculpting stuff that I can't figure out

Will Hobbs
Will Hobbs12:10 PM

Ok

Will Hobbs
Will Hobbs3:03 PM

Nice job on the cad

Will Hobbs
Will Hobbs3:03 PM

I will move the middle wheel down

Alex Larson Freeman
Alex Larson Freeman8:49 PM

Thanks, took me a while

2016-08-17
Bo Baird
Bo Baird12:08 PM

@Bo Baird has joined the channel

2016-09-07
Bo Baird
Bo Baird3:31 PM

am i in?

Will Hobbs
Will Hobbs3:31 PM

you are in

Clio Batali
Clio Batali3:31 PM

So in

Jack Chapman
Jack Chapman4:55 PM

@Jack Chapman has joined the channel

2016-09-08
Kenneth Wiersema
Kenneth Wiersema4:42 PM

@Kenneth Wiersema has joined the channel

Kenneth Wiersema
Kenneth Wiersema6:16 PM

Will, Alex, Bo, could one of you share the t-shirt launcher file with me?

Bo Baird
Bo Baird6:18 PM

give me your email

Bo Baird
Bo Baird6:19 PM

ill invite you with that

Will Hobbs
Will Hobbs6:19 PM

Just sent you an invite

Bo Baird
Bo Baird6:19 PM

never mind

Kenneth Wiersema
Kenneth Wiersema6:21 PM

send it to my account, thats the one I use fusion with

Alex Larson Freeman
Alex Larson Freeman6:22 PM

Is there a way to make the CAD open to everyone on the sub team?

Bo Baird
Bo Baird6:22 PM

idk

Alex Larson Freeman
Alex Larson Freeman6:23 PM

We should look into that

Will Hobbs
Will Hobbs6:23 PM

You have to share it to all of their accounts as far as I know

Alex Larson Freeman
Alex Larson Freeman6:23 PM

Ah

Bo Baird
Bo Baird6:23 PM

i think its individual invite only

Alex Larson Freeman
Alex Larson Freeman6:23 PM

Makes sense, we just need everyone to have an account

Bo Baird
Bo Baird6:23 PM

indeed

Kenneth Wiersema
Kenneth Wiersema6:27 PM

what else on the file needs work?

Bo Baird
Bo Baird7:50 PM

hey joncoonan

Jon Coonan
Jon Coonan7:57 PM

Yes

2016-09-09
Jack Chapman
Jack Chapman6:26 PM

Is the 10:00 meeting this weekend on saturday or sunday?

Alex Larson Freeman
Alex Larson Freeman7:20 PM

Saturday, if you mean the CNC etc

Jack Chapman
Jack Chapman8:50 PM

thank you

2016-09-11
Kenneth Wiersema
Kenneth Wiersema7:54 PM

Do any of you have any thoughts on the CNC debris collector? I currently can't find an clear benefit to either design, other than whatever design that we chose has to have a brush on it to work with the metal.

Alex Larson Freeman
Alex Larson Freeman7:56 PM

I'll look into it, we should probably figure out what will be best for our specific setup

Kenneth Wiersema
Kenneth Wiersema7:57 PM

Mr Chee sent an email about the add-ons with the email talking about the pegboard he bought. Three of the are things we have to build on our own, on is something we need to assemble.

Alex Larson Freeman
Alex Larson Freeman7:59 PM

Right. I was thinking we should see what other teams use etc

Will Hobbs
Will Hobbs8:00 PM

I think we could easily do it ourselves and it would be half the price

2016-09-12
victoria kleiven
victoria kleiven5:30 PM

@victoria kleiven has joined the channel

2016-09-13
Enrique Chee
Enrique Chee10:04 PM

@Enrique Chee has joined the channel

Enrique Chee
Enrique Chee10:33 PM

The pegboards and tools should all be here by Sept. 23rd. We need to meet and organize. Can we meet Sat. 9/24 from 10 am to about 4 pm ?

Enrique Chee
Enrique Chee10:35 PM

I basically order duplicates of what we have. I think we need to label all stuff that goes on the peg board so it will not be confuse with tools that goes in our tool box.

Enrique Chee
Enrique Chee10:36 PM

Why is Alex not reading this ? I have extended my curfew with slack for tonight. No response mechanics ?

Jon Coonan
Jon Coonan10:38 PM

Alex is asleep

Jon Coonan
Jon Coonan10:38 PM

He just went to bed

Will Hobbs
Will Hobbs10:39 PM

I could meet on the 24th anytime after about 11am

Enrique Chee
Enrique Chee10:41 PM

ok, maybe we should also announce to team after I confirm 9/24. It all depends if all the stuff is delivered by then.

Will Hobbs
Will Hobbs10:41 PM

Ok

2016-09-14
Enrique Chee
Enrique Chee8:44 PM

Which would you label ? The tools that go on the peg board or the tools that goes in our toolbox.

Enrique Chee
Enrique Chee8:45 PM

How should we label or mark the tools ?

Will Hobbs
Will Hobbs8:45 PM

I would say the ones on the pegboard

Enrique Chee
Enrique Chee8:45 PM

Why ?

Will Hobbs
Will Hobbs8:45 PM

And I think we should paint the handles a certain color

Lucas Rininger
Lucas Rininger8:46 PM

People need to know where to put stuff on the pegboard, but the toolbox is organized by section, not by specific tool

Will Hobbs
Will Hobbs8:46 PM

I just feel like the pegboard is the one that should be marked but it could be either one

Alex Larson Freeman
Alex Larson Freeman8:46 PM

Could we just use a labelmaker?

Alex Larson Freeman
Alex Larson Freeman8:47 PM

Color coding seems unnecessary

Will Hobbs
Will Hobbs8:47 PM

I feel like the labels from a laborer would peel off

Will Hobbs
Will Hobbs8:48 PM

Labler not laborer

Alex Larson Freeman
Alex Larson Freeman8:48 PM

that's a good point

Enrique Chee
Enrique Chee8:48 PM

Labels will come off . We can wrap color electrical tape on the tools . Regarding the pegboard we can outline the tools on the pegboard once we commit to location .

Alex Larson Freeman
Alex Larson Freeman8:49 PM

I like the tape idea, maybe we can color code the drawers of the toolbox?

Alex Larson Freeman
Alex Larson Freeman8:49 PM

and then a different color for tools on the pegboard

Will Hobbs
Will Hobbs8:50 PM

I like the electrical tape idea

Enrique Chee
Enrique Chee8:50 PM

Another thing we need to figure where to place our pegboard . 2 options . Where the current Nvidia banner is or where the photos are hanging

Lucas Rininger
Lucas Rininger8:50 PM

Personally I did fine last year without color coding on the toolbox, and that was my first year. I think many would be the same

Will Hobbs
Will Hobbs8:50 PM

I think where the picture are hanging would be best

Enrique Chee
Enrique Chee8:51 PM

I like where the wall where the pictures are hanging but it is further away from the 2 mechanics table .

Alex Larson Freeman
Alex Larson Freeman8:52 PM

@Lucas Rininger Some people aren't as organized, but it won't make it worse for the rest of us

Lucas Rininger
Lucas Rininger8:52 PM

That's reasonable

Enrique Chee
Enrique Chee8:53 PM

I agree we don't need to color the tool box drawers. We just need to distinguish tools on the pegboard from tools in the toolbox . Make sense ?

Alex Larson Freeman
Alex Larson Freeman8:53 PM

That should work

Alex Larson Freeman
Alex Larson Freeman8:53 PM

the toolbox is already organized after all

Will Hobbs
Will Hobbs8:54 PM

Sounds good

Alex Larson Freeman
Alex Larson Freeman8:54 PM

I vote blue and yellow

Alex Larson Freeman
Alex Larson Freeman8:55 PM

even the tools can be themed

Enrique Chee
Enrique Chee8:59 PM

I think we should mark the tools in the toolbox cause then at competition if we lend stuff they will now it belongs to us .

Will Hobbs
Will Hobbs9:00 PM

That works to

Will Hobbs
Will Hobbs9:01 PM

I don't think it matter that much for us as long as all the tools get back to the right place

2016-09-17
Dana Batali
Dana Batali11:24 AM

@Dana Batali has joined the channel

Binnur Alkazily
Binnur Alkazily12:43 PM

@Binnur Alkazily has joined the channel

2016-09-18
Riyadth Al-Kazily
Riyadth Al-Kazily11:41 AM

@Riyadth Al-Kazily has joined the channel

2016-09-21
Rose Bandrowski
Rose Bandrowski4:22 PM

@Rose Bandrowski has joined the channel

2016-09-23
Kenneth Wiersema
Kenneth Wiersema10:38 AM

Will, Jack, The current plan I have for the presentation for next meeting is we grab the scaling system, and the spare chassis that's been floating around, but only if we get to be in the shop (313). We should have a computer with Fusion 360 on it to show CAD as well. The scaling system isn't attached to anything, so we can show a smaller example of the engineering we do. Please respond/change the idea.

Jack Chapman
Jack Chapman7:37 PM

I like it as a demonstration, but we still need to come up with what we are going to cover in what order. I vote we start with a quick overview of how engineering splits up during build season, then go into the build the robot aspect, then cad, with a question period at the end of each category.

Kenneth Wiersema
Kenneth Wiersema8:46 PM

I'd save the questions for the end, but I like the order. Possible start out with what we do, and the fact that it's a bit more than just building stuff.

Will Hobbs
Will Hobbs8:47 PM

Sounds good guys

2016-09-24
Bill Bandrowski
Bill Bandrowski8:48 AM

@Bill Bandrowski has joined the channel

Jack Stratton
Jack Stratton11:16 PM

@Jack Stratton has joined the channel

2016-09-27
Fiona Morrison
Fiona Morrison10:36 AM

@Fiona Morrison has joined the channel

Sophie Holzer
Sophie Holzer11:58 AM

@Sophie Holzer has joined the channel

2016-09-28
Lucas Rininger
Lucas Rininger9:06 AM

I missed the meeting and there wasn't any specific info on the leadership meeting notes. I'm curious as to what we're doing besides presenting about the various things that we do. Do we have a hands-on activity planned or are we just doing a presentation/ Q&A?

Lucas Rininger
Lucas Rininger9:12 AM

Reading it a little more closely it looks like we're just doing presentations today.

Rose Bandrowski
Rose Bandrowski9:35 AM

Pretty much, you can allow time for questions at the end of your presentation at the end though

Lucas Rininger
Lucas Rininger9:35 AM

Thanks

Rose Bandrowski
Rose Bandrowski9:36 AM

No problem

Timo Lahtinen
Timo Lahtinen8:45 PM

@Timo Lahtinen has joined the channel

2016-09-29
Bo Baird
Bo Baird8:18 PM

hey folks if any one is interested there is a pretty neat documentary on netflix called "cosmodrome"

Bo Baird
Bo Baird8:20 PM

its about the Russians in the space race and how they were 20 years ahead of us in terms of their rocket technology with out anyone knowing because they lost funding the moment they had a space worthy prototype.

Alex Larson Freeman
Alex Larson Freeman8:24 PM

the video is in #random but I can link it here

Alex Larson Freeman
Alex Larson Freeman8:25 PM

Courtesy of Bo

Bo Baird
Bo Baird8:26 PM

sick!!

Bo Baird
Bo Baird8:27 PM

This is worth the hour of your life it costs to watch it

Alex Larson Freeman
Alex Larson Freeman8:27 PM

I still gotta watch it

Bo Baird
Bo Baird8:28 PM

do it nerd

Bo Baird
Bo Baird8:28 PM

you wont

Alex Larson Freeman
Alex Larson Freeman8:28 PM

pls

2016-10-04
John Sachs
John Sachs9:40 PM

@John Sachs has joined the channel

2016-10-05
Jeff Dalton
Jeff Dalton11:02 AM

@Jeff Dalton has joined the channel

2016-10-06
Dana Batali
Dana Batali3:25 PM

a nice summary of motors and motor controllers (cross posted to programming):
a nice summary of motors and motor controllers: https://www.youtube.com/watch?v=5thxBgew7N0&feature=youtu.be

Alex Larson Freeman
Alex Larson Freeman3:26 PM

Thanks Dana!

Dana Batali
Dana Batali3:41 PM

here’s a cool ball-bot

Jack Chapman
Jack Chapman7:36 PM

impressive

2016-10-08
Enrique Chee
Enrique Chee2:37 PM

Can some of you (students) look at Banebots and come up with a list of wheels we should buy soon. Thanks

2016-10-09
Riyadth Al-Kazily
Riyadth Al-Kazily2:41 PM

West Coast Products makes an interesting type of gearbox/wheel mounting system: http://www.wcproducts.net/
The WCP SS gearbox looks nice, especially in that it's easy to see if something is going wrong with it.
But I think the Single Reduction Clamping Gearbox (http://www.wcproducts.net/217-4156) could be excellent for prototyping using VersaFrame tubing.

Riyadth Al-Kazily
Riyadth Al-Kazily2:56 PM

And this little gearbox seems awesome, if you want to put a small motor where a CIM fits: http://www.wcproducts.net/217-3198

Riyadth Al-Kazily
Riyadth Al-Kazily3:26 PM

As an idea for an off-season project, I would recommend designing and building a winch system to fit in the smallest space possible. We've at least attempted to use a winch system on all of our robots so far (Atlas belt winder; Gaea forklift elevator; Ares scaling system), and it's likely to be useful in the future. I saw some nice designs on Chief Delphi that could give us some inspiration.

Jack Stratton
Jack Stratton4:13 PM

second off season: automated open-source CNC garden plot https://farmbot.io/

2016-10-11
Kenneth Wiersema
Kenneth Wiersema3:51 PM

What are we(Mechanics+Cad+Electrical/Pneumatics?) doing for tomorrows meeting, and what still needs to be worked out? Last

Kenneth Wiersema
Kenneth Wiersema3:51 PM

I heard, we were going to a rotation system, but not much more beyond that.

Clio Batali
Clio Batali4:34 PM

Good question - there will mostly be stations for the machinery so people can get approved for using the shop. Also a small room tour (tape color coding explained). We need to decide specifically who will be doing what. @Will Hobbs @Alex Larson Freeman

Kenneth Wiersema
Kenneth Wiersema4:37 PM

I thought Mr. Chee said that there wasn't going to be any tool approving tomorrow, that would happen at the meeting after that.

Enrique Chee
Enrique Chee5:40 PM

Correct . You guys can demo and go over safety .

Enrique Chee
Enrique Chee5:41 PM

No new member is approved but you can Demo and supervise .

Alex Larson Freeman
Alex Larson Freeman6:11 PM

I'm thinking we have around 6 stations: CAD, safety, electronics, prototyping, and two stations for the tools (mill, lathe, etc.)

Alex Larson Freeman
Alex Larson Freeman6:13 PM

*electronics and pneumatics

Alex Larson Freeman
Alex Larson Freeman6:14 PM

I like the tour idea

Kenneth Wiersema
Kenneth Wiersema6:19 PM

Would the tools be divided into showing the power tools as one station and the other station being for the hand tools?

Kenneth Wiersema
Kenneth Wiersema6:21 PM

And Prototyping covering the wood tools as well, or do we just integrate that into the hand tools?

Alex Larson Freeman
Alex Larson Freeman6:24 PM

Prototyping can integrate hand tools

Alex Larson Freeman
Alex Larson Freeman6:24 PM

Power tools could be split up

Kenneth Wiersema
Kenneth Wiersema6:30 PM

We have 1 hour 45 minutes to cover 6 stations, so ~15 minutes per station. With six stations that means that one leadership person per station.

Kenneth Wiersema
Kenneth Wiersema6:32 PM

Should we save figuring out what were going to do for tomorrow and have all of us get there at 5:30? I doubt that we're going to be able to organize everything over slack.

Alex Larson Freeman
Alex Larson Freeman6:44 PM

That sounds good, we should assign each person a station and meet at 5:30 to discuss

Alex Larson Freeman
Alex Larson Freeman6:44 PM

Anyone have a particular station they would prefer?

Bo Baird
Bo Baird6:47 PM

i can take cad

Bo Baird
Bo Baird6:48 PM

or at least a part of it

Lucas Rininger
Lucas Rininger6:49 PM

I can do whichever so long as it is not electronics

Jack Chapman
Jack Chapman6:50 PM

I could take on prototyping

Will Hobbs
Will Hobbs6:59 PM

I can run safety on the mill or lathe

Will Hobbs
Will Hobbs7:00 PM

Alex can you do safety for the drill press, lathe, or bandsaw?

Kenneth Wiersema
Kenneth Wiersema7:02 PM

I can do the hand tools, I still think we need a separate category for the hand tools, and have prototyping more for the wood based tools.

Will Hobbs
Will Hobbs7:03 PM

I don't think we need a prototyping sub group

Will Hobbs
Will Hobbs7:04 PM

I would have a power tool safety for hand tools, lathe, mill, and drill press and then a section for CAD and a section for electronics/pneumatics

Lucas Rininger
Lucas Rininger7:05 PM

What stations still need someone on them?

Will Hobbs
Will Hobbs7:05 PM

all stations will need somebody

Lucas Rininger
Lucas Rininger7:06 PM

Clearly, but which ones have people not claimed

Will Hobbs
Will Hobbs7:07 PM

IDK

Will Hobbs
Will Hobbs7:07 PM

we can finalize tomorrow

Alex Larson Freeman
Alex Larson Freeman7:10 PM

Alright

Kenneth Wiersema
Kenneth Wiersema7:10 PM

Fine, but do we at least have a list of which categories. Will, from your message, I got there is going to be a group for the Lathe and Mill, a group for the band saw, drill press, grinder, a group for hand tools, a group for cad, and a group for electrical/pneumatics.

Alex Larson Freeman
Alex Larson Freeman7:10 PM

Sounds good

Alex Larson Freeman
Alex Larson Freeman7:10 PM

I can do safety for the mill if no one else wants to

Alex Larson Freeman
Alex Larson Freeman7:12 PM

Bo will take CAD I guess

Alex Larson Freeman
Alex Larson Freeman7:12 PM

@Will Hobbs: want to do the lathe?

Will Hobbs
Will Hobbs7:13 PM

sure

Alex Larson Freeman
Alex Larson Freeman7:13 PM

Nice

Kenneth Wiersema
Kenneth Wiersema7:13 PM

I could do hand tools

Alex Larson Freeman
Alex Larson Freeman7:13 PM

Alright

Alex Larson Freeman
Alex Larson Freeman7:13 PM

@Jack Chapman: you up for bandsaw/drill press?

Lucas Rininger
Lucas Rininger7:14 PM

I could do the bandsaw

Alex Larson Freeman
Alex Larson Freeman7:14 PM

Nice

Will Hobbs
Will Hobbs7:14 PM

I think we should do mill/drill press

Alex Larson Freeman
Alex Larson Freeman7:14 PM

Oh yeah that makes more sense

Alex Larson Freeman
Alex Larson Freeman7:14 PM

I got that

Alex Larson Freeman
Alex Larson Freeman7:14 PM

Lucas on bandsaw then?

Alex Larson Freeman
Alex Larson Freeman7:15 PM

Assuming @Clio Batali is doing electrical?

Jack Chapman
Jack Chapman7:18 PM

What has not been taken?

Kenneth Wiersema
Kenneth Wiersema7:20 PM

So, Will on Lathe,

Kenneth Wiersema
Kenneth Wiersema7:21 PM

Alex on Mill/Drill press. Kenneth on Hand Tools, Lucas on Band saw, Bo on Cad, Clio on Electrical.

Kenneth Wiersema
Kenneth Wiersema7:21 PM

I could stand having a second person to go over hand tools

Alex Larson Freeman
Alex Larson Freeman7:22 PM

Jack if you want to lead a room tour

Alex Larson Freeman
Alex Larson Freeman7:22 PM

Thoughts?

Jack Chapman
Jack Chapman7:23 PM

OK sounds good, and are we still doing the 5:30

Kenneth Wiersema
Kenneth Wiersema7:24 PM

I don't know if a room tour is absolutely needed, the only things real left to point out is where we keep materials and parts.

Alex Larson Freeman
Alex Larson Freeman7:24 PM

Either way

Alex Larson Freeman
Alex Larson Freeman7:24 PM

If you guys want to work together that's cool

Jack Chapman
Jack Chapman7:25 PM

Also fine with me

Rose Bandrowski
Rose Bandrowski7:25 PM

if not a room tour please tell group where things are at least upon entrance.

Alex Larson Freeman
Alex Larson Freeman7:25 PM

Good point

Kenneth Wiersema
Kenneth Wiersema7:25 PM

Might be easier that way

Alex Larson Freeman
Alex Larson Freeman7:25 PM

Rose are you part of marketing orientation or touring mechanics?

Rose Bandrowski
Rose Bandrowski7:25 PM

Touring mechanics

Rose Bandrowski
Rose Bandrowski7:26 PM

I may help marketing if they need it although I doubt they will, Jon seems to have it under control

Lucas Rininger
Lucas Rininger7:26 PM

I think that it is really, really important to know where everything is. It saves you time and the person you have to ask for help's time

Jack Chapman
Jack Chapman7:26 PM

We could take the fist few minutes to divide people up, point out stations and do a fast room tour

Lucas Rininger
Lucas Rininger7:27 PM

I think that is perfect, Jack

Alex Larson Freeman
Alex Larson Freeman7:27 PM

Good idea

Rose Bandrowski
Rose Bandrowski7:28 PM

I think that over complicates things you can just show the whole room where everything is, everything's pretty visible from the middle part.

Rose Bandrowski
Rose Bandrowski7:28 PM

It will probably work either way though

Kenneth Wiersema
Kenneth Wiersema7:30 PM

Do the room tour as an entire group from the center. I don't think we should go into to much detail, since most of it could still change Either way still six groups, see my earlier comment about timing, but more like 12-13 minutes with the brief room tour added.

Alex Larson Freeman
Alex Larson Freeman7:31 PM

I would suggest grouping everyone in the center and showing roughly where everyone is

Jack Stratton
Jack Stratton7:31 PM

Just point at stuff. "This is a mill. It mills. This is a drill press. It drills. This is a lathe. It turns." for 30 seconds then split up

Alex Larson Freeman
Alex Larson Freeman7:31 PM

People can. E assigned group numbers alphabetically

Alex Larson Freeman
Alex Larson Freeman7:31 PM

* can be

Rose Bandrowski
Rose Bandrowski7:31 PM

exactly what I meant, we just need to know where the general is and stuff will likely be moved around anyway. People will get to know the room from being in it

Alex Larson Freeman
Alex Larson Freeman7:31 PM

@Jack Stratton: pretty much

Alex Larson Freeman
Alex Larson Freeman7:32 PM

Alright we have a plan

Kenneth Wiersema
Kenneth Wiersema7:33 PM

Do think we need to point out generally where materials are, since we won't have a group talking about it. For example, point out the metal, the middle shelfs and prototyping parts.

Alex Larson Freeman
Alex Larson Freeman7:33 PM

Right

Alex Larson Freeman
Alex Larson Freeman7:33 PM

That can be part of the room overview

Kenneth Wiersema
Kenneth Wiersema7:34 PM

That was my thought

Jack Chapman
Jack Chapman7:36 PM

do we still need to meet at 5:30?

Kenneth Wiersema
Kenneth Wiersema7:36 PM

Yes

Jack Chapman
Jack Chapman7:37 PM

ok

Enrique Chee
Enrique Chee7:38 PM

I won't be there till 5:45 pm .

Enrique Chee
Enrique Chee7:38 PM

Meeting starts at 6:15

Kenneth Wiersema
Kenneth Wiersema7:39 PM

Okay, meet at 5:45 then and run back to 316 at 6:05-6:10

Jack Chapman
Jack Chapman7:40 PM

Sounds good

Enrique Chee
Enrique Chee7:40 PM

You guys can meet right after school on wed to plan if you want . We need to fix Aries for girls gen .

Lucas Rininger
Lucas Rininger8:21 PM

I won't be able to be there right after school

Kenneth Wiersema
Kenneth Wiersema8:22 PM

I think we should be fine, as long as everyone read the chat.

Kenneth Wiersema
Kenneth Wiersema8:23 PM

Meeting at 5:45

Kenneth Wiersema
Kenneth Wiersema8:24 PM

Ares could be done on a weekend

Enrique Chee
Enrique Chee8:25 PM

We need Ares fix ASAP before Thurs. for the girls driving team to practice.

2016-10-12
Enrique Chee
Enrique Chee8:48 PM

Keep me updated on cad files for Gaia please

Alex Larson Freeman
Alex Larson Freeman8:49 PM

I'll let you know when I hear back

Alex Larson Freeman
Alex Larson Freeman8:58 PM

apparently the complete version of GAEA is in Onshape

Alex Larson Freeman
Alex Larson Freeman8:59 PM

I don't have access to it yet

Enrique Chee
Enrique Chee8:59 PM

Please confirm

Enrique Chee
Enrique Chee11:39 PM

I don't see Gaea on Onshape . Does anyone ?

2016-10-13
Enrique Chee
Enrique Chee12:11 AM

Ok . Gaea is somewhere else . I will let you guys hunt . Clue : website

Enrique Chee
Enrique Chee1:06 PM

One of the link is not right .

2016-10-15
Enrique Chee
Enrique Chee9:52 PM

Did we figure out the bad link for the cad file for GAEA in our website ? Please consult with James .

James Slattery
James Slattery9:53 PM

What do you guys want the link to be?

Enrique Chee
Enrique Chee9:57 PM

It should go to someone's Dropbox ? containing our entire CAD files for GAEA . Please ask Will and Alex. I believe the Dropbox files belong to a student who was on our team 2 years ago . Elan ? Or we should ask Elan or Xander .

Enrique Chee
Enrique Chee9:57 PM

Any ideas ? Will and Alex ?

Will Hobbs
Will Hobbs9:57 PM

I have no idea what the problem is

Will Hobbs
Will Hobbs9:58 PM

The link brings you to a Dropbox download but it gives you an error when you try to download

Enrique Chee
Enrique Chee9:58 PM

Go to our website and click on the last link for cad file of the full robot .

Enrique Chee
Enrique Chee9:59 PM

The link for the chassis works . Does this make sense Will ?

Will Hobbs
Will Hobbs9:59 PM

Ok

Enrique Chee
Enrique Chee9:59 PM

I am referring to GAEA .

Will Hobbs
Will Hobbs10:00 PM

I only have tried to get the chassis file but the download on the chassis file does not work

Enrique Chee
Enrique Chee10:00 PM

Remember you were asking for the Gaea files last week ?

Will Hobbs
Will Hobbs10:00 PM

I was asking for the chassis file

Will Hobbs
Will Hobbs10:01 PM

I do not need the GAEA file

Enrique Chee
Enrique Chee10:01 PM

The download for the chassis files worked for me . I want the entire robot .

Enrique Chee
Enrique Chee10:02 PM

In case we need it later

Enrique Chee
Enrique Chee10:02 PM

Do you have a drop box account ?

Will Hobbs
Will Hobbs10:02 PM

I do not but Alex does

Will Hobbs
Will Hobbs10:03 PM

When we tried the download we could get it into his drop box but not from the Dropbox to the computer

Enrique Chee
Enrique Chee10:03 PM

That is why it is not working for you . Again we need to figure out the other link . Please contact Xander and Elan and find out whose Dropbox it is that is saved on

Enrique Chee
Enrique Chee10:04 PM

I was able to put the chassis file in Onshape but I have not shared with you guys .

Enrique Chee
Enrique Chee10:05 PM

I will share once we figure out the file for the entire GAEA.

Enrique Chee
Enrique Chee10:07 PM

James , thanks for asking but let's figure out whose Dropbox the files are coming from and then we can share with you to fix .

Enrique Chee
Enrique Chee10:10 PM

Anyone know Dropbox enough to figure this out ? I have posted and asked in Dropbox to the owner of the cad files . No response so far .

Enrique Chee
Enrique Chee10:11 PM

I bet you it is Elan's Dropbox .

Enrique Chee
Enrique Chee10:24 PM

Enrique Chee
Enrique Chee10:25 PM

James, is this the best way ? Storage issues ?

Enrique Chee
Enrique Chee10:27 PM

Enrique Chee
Enrique Chee10:41 PM

Will and Alex , do you have Elan and Xander contacts ?

Enrique Chee
Enrique Chee10:50 PM

Enrique Chee
Enrique Chee10:52 PM

@Enrique Chee pinned their Post FRCresourcesforengineeringandmechanicssubteam|Online FRC resources for engineering and mechanics subteam.> to this channel.

Enrique Chee
Enrique Chee10:52 PM

@Enrique Chee pinned their File to this channel.

Enrique Chee
Enrique Chee10:52 PM

@Enrique Chee pinned their File to this channel.

Enrique Chee
Enrique Chee10:54 PM

Enrique Chee
Enrique Chee10:54 PM

@Enrique Chee pinned their File to this channel.

Enrique Chee
Enrique Chee10:57 PM

@Enrique Chee set the channel topic:

2016-10-19
Enrique Chee
Enrique Chee11:14 PM

whobbs1496 wat was the diameter of our shopvac ?

Enrique Chee
Enrique Chee11:14 PM

what

2016-10-20
Will Hobbs
Will Hobbs7:45 AM

30mm

2016-10-21
Enrique Chee
Enrique Chee2:08 PM

We still have a lot to do with the CNC (build a wall , test carve on metal ) , finish installing the lathe , and more organization . Who is willing to meet on Sat. Oct 29th from 10am to about 4 pm ?

Will Hobbs
Will Hobbs2:40 PM

I can probably be there

Alex Larson Freeman
Alex Larson Freeman2:41 PM

I should be able to do that

Lucas Rininger
Lucas Rininger4:52 PM

I can probably be there as well

Enrique Chee
Enrique Chee5:48 PM

Let's confirm early next week . Anyone else ? Kenneth , Bo , jack , rose , Clio ?

Rose Bandrowski
Rose Bandrowski5:48 PM

I'm not sure how helpful I'll be, but maybe I can help?

Enrique Chee
Enrique Chee5:54 PM

It's about learning the CNC and other mechanic stuff.

Rose Bandrowski
Rose Bandrowski6:04 PM

Ok sure I'll try and be there

Kenneth Wiersema
Kenneth Wiersema6:06 PM

I can be there later in the day, had some plans but they won't take all day.

Bo Baird
Bo Baird7:37 PM

i can't prommise anything. I'm scedualed to work that day. if they don't need me ill be there

Jack Chapman
Jack Chapman8:06 PM

I won't be able to make it on saturday

2016-10-26
Jon Coonan
Jon Coonan6:42 PM

@Jon Coonan has joined the channel

Jon Coonan
Jon Coonan6:43 PM

@Jon Coonan

Olivia Pells
Olivia Pells6:43 PM

@Olivia Pells has joined the channel

Lia Johansen
Lia Johansen8:08 PM

@Lia Johansen has joined the channel

Andrew Peterson
Andrew Peterson9:39 PM

@Andrew Peterson has joined the channel

Andrew Peterson
Andrew Peterson9:51 PM

@alex_larsonfreeman what account should I create for the cad software download?

Alex Larson Freeman
Alex Larson Freeman9:54 PM

Will can add you to the Spartronics folder, just make sure you let us know if you are using an email for Fusion which is different from the one you have on Slack

2016-10-27
Benjamin Soldow
Benjamin Soldow12:45 AM

@Benjamin Soldow has joined the channel

Cruz Strom
Cruz Strom6:07 AM

@Cruz Strom has joined the channel

Dana Batali
Dana Batali10:29 AM

a great introduction to pneumatics! https://www.youtube.com/watch?v=JN9KCOp3hHA&feature=youtu.be

Dana Batali
Dana Batali10:34 AM

Ken Stafford seems cool: here’s another talk called “week-1 tips”… (pretty long)
https://www.youtube.com/watch?v=pTY8m8vM8u0

Andrew Peterson
Andrew Peterson3:59 PM

my email is the same as it is on slack

Andrew Peterson
Andrew Peterson3:59 PM

@Will Hobbs

Kaedric Holt
Kaedric Holt5:04 PM

@Kaedric Holt has joined the channel

Kaedric Holt
Kaedric Holt5:05 PM

@Will Hobbs Mine too. And what time was the shop cleanup planned for?

Alex Larson Freeman
Alex Larson Freeman5:09 PM

10 AM to 4 PM on Saturday

Kaedric Holt
Kaedric Holt5:42 PM

Ok thx Alex

Peter Hall
Peter Hall6:06 PM

@Peter Hall has joined the channel

2016-10-28
Samantha Rosen
Samantha Rosen11:36 AM

@Samantha Rosen has joined the channel

2016-10-29
Harper Nalley
Harper Nalley10:11 PM

@Harper Nalley has joined the channel

2016-11-05
Luke Frank
Luke Frank12:34 PM

@Luke Frank has joined the channel

2016-11-06
Charlotte Larson Freeman
Charlotte Larson Freeman10:21 AM

@Charlotte Larson Freeman has joined the channel

Chris Rininger
Chris Rininger10:39 AM

@Chris Rininger has joined the channel

Kate Treviño-Yoson
Kate Treviño-Yoson11:37 AM

@Kate Treviño-Yoson has joined the channel

Adrien Chaussabel
Adrien Chaussabel12:05 PM

@Adrien Chaussabel has joined the channel

Chris Mentzer
Chris Mentzer1:03 PM

@Chris Mentzer has joined the channel

Jeremy Lipschutz
Jeremy Lipschutz7:11 PM

@Jeremy Lipschutz has joined the channel

Finn Mander
Finn Mander7:12 PM

@Finn Mander has joined the channel

2016-11-07
Robert Galvin
Robert Galvin6:41 PM

@Robert Galvin has joined the channel

Kenneth Wiersema
Kenneth Wiersema8:43 PM

Reminder, next meeting there's going to be the safety test on the sheets give out last meeting. You need to pass to use any of the tools in the shop.

Mike Rosen
Mike Rosen9:23 PM

@Mike Rosen has joined the channel

Binnur Alkazily
Binnur Alkazily9:30 PM

@Kenneth Wiersema what is the plan to ensure programmers stay safe?

2016-11-09
Enrique Chee
Enrique Chee1:03 PM

Working on it. I will share soon.

Olivia Pells
Olivia Pells1:05 PM

@Olivia Pells has left the channel

Parker Hutchinson
Parker Hutchinson4:10 PM

@Parker Hutchinson has joined the channel

James Sovick
James Sovick10:39 PM

@James Sovick has joined the channel

2016-11-10
Marie Sachs
Marie Sachs5:35 PM

@Marie Sachs has joined the channel

2016-11-17
Dana Batali
Dana Batali10:12 AM

nice overview on drivetrain designs here: https://www.youtube.com/watch?v=6lmKLTZZLBE&feature=em-lss

Enrique Chee
Enrique Chee12:23 PM

Thanks Dana . I will pin this PDF file. We actually used this file the first 2 years in engineering to teach drivetrains.

Enrique Chee
Enrique Chee12:25 PM

Good design file for drivetrain. Must read for all mechanics.

Tom Wiggin
Tom Wiggin4:37 PM

@Tom Wiggin has joined the channel

Tom Wiggin
Tom Wiggin4:39 PM

just in case we needed any more machines

Tom Wiggin
Tom Wiggin4:39 PM

lol they stole our brand

2016-11-18
Dana Batali
Dana Batali10:08 AM

@Dana Batali pinned @Enrique Chee’s File to this channel.

2016-11-19
Enrique Chee
Enrique Chee10:32 AM

Can someone in engineering check our inventory for 1/2 inch hex bar at our next meeting ?

Tom Wiggin
Tom Wiggin11:13 AM

We have an inventory system?

Enrique Chee
Enrique Chee11:14 AM

No . But we need one

Tom Wiggin
Tom Wiggin11:15 AM

If we are going to make an inventory system we better start digital

Enrique Chee
Enrique Chee11:16 AM

We know Tom

Kaedric Holt
Kaedric Holt5:58 PM

I will. Also, when is the next meeting?

Rose Bandrowski
Rose Bandrowski6:01 PM

Check the calendar

Kaedric Holt
Kaedric Holt6:03 PM

Ah yes. Forgot about that, thx Rose

Rose Bandrowski
Rose Bandrowski6:03 PM

No problem

2016-11-22
Will Hobbs
Will Hobbs4:58 PM

FYI we will be meeting on Saturday 12-17 from 11:30 to 4:30. We still have some work that needs to get done before kickoff and we will not have enough time during our other meetings to get it done.

Here is a list of things we will need to get done.
1) get the Suck it working with vacuum hose(build a system)
2) test the CNC
3) build the stand for the digital counter for the new lathe
4) Fix the 3D printer
5) unpack stuff from Vex
6) inventory various parts ( nuts/bolts, motors, etc)

Kaedric Holt
Kaedric Holt5:19 PM

NOOBIE QUESTION!WARNING! CNC?

Will Hobbs
Will Hobbs5:22 PM

computer numerical control. It is a computer aided router that can do precise milling operations. We have a CNC from inventables called the x carve.

Will Hobbs
Will Hobbs5:23 PM

if you go to inventables website you can learn more about it.

Kaedric Holt
Kaedric Holt5:23 PM

Ah, the massive thing on the middle table?

Will Hobbs
Will Hobbs5:24 PM

this thing

Kaedric Holt
Kaedric Holt5:24 PM

Yup

Kaedric Holt
Kaedric Holt5:24 PM

Thx Will

Tom Wiggin
Tom Wiggin5:24 PM

I have a printerbot play that we could use if we needed another 3d printer

2016-11-28
Tom Wiggin
Tom Wiggin6:14 PM

when can I bring it in?

Bo Baird
Bo Baird6:20 PM

I'm afraid we don't have a need for a 3D printer at the moment @Tom Wiggin we apriciate the offer. Thank you for your willingness to contribute. We will know who to ask if we ever need another 3D printer besides the one that we already have.

2016-11-29
Tom Wiggin
Tom Wiggin7:29 AM

I was hoping I could get some help with it really

Tom Wiggin
Tom Wiggin7:29 AM

it hasn't printed a single thing since I bought it and its still in mint condition but it just won't do anything at all no matter what I do

Clio Batali
Clio Batali4:37 PM

Tom, I don't think robotics is the best place for debugging your printer, but if you want help maybe ask for it outside of team meetings

2016-12-02
Tom Wiggin
Tom Wiggin10:59 AM

@Tom Wiggin has left the channel

2016-12-07
Will Hobbs
Will Hobbs4:13 PM

Reminder don't forget to complete your CAD model. The model needs to be completed and dimensioned before you can build your part.

2016-12-08
Finn Mander
Finn Mander5:38 PM

Hope it's ok that I ask here: Does anyone have an hdmi capture card that I can use at FLL? They are typically used with recording video games.

2016-12-09
Kaedric Holt
Kaedric Holt7:56 AM

Is the fll setup going ahead tonight?

Will Hobbs
Will Hobbs8:13 AM

Yes

Kaedric Holt
Kaedric Holt10:02 AM

K

2016-12-13
Will Hobbs
Will Hobbs5:41 PM

Reminder do not forget to finish your CAD design. It is due tommorow!

2016-12-31
Jim Carr
Jim Carr8:55 AM

@Jim Carr has joined the channel

2017-01-04
Sean Hooyer
Sean Hooyer6:34 PM

@Sean Hooyer has joined the channel

2017-01-05
Alex Larson Freeman
Alex Larson Freeman5:14 PM

Mechanics! This Sunday we will need about 3 people to meet at 11 AM with Coach Chee and I to go to the lumber store. We will purchase materials for building this year's game elements! These are vital for testing our robot and simulating the playing field. Who's up for it?

Kaedric Holt
Kaedric Holt5:40 PM

I'm game

Kenneth Wiersema
Kenneth Wiersema5:57 PM

I can help sunday for getting materials and building the items.

James Sovick
James Sovick6:02 PM

Sure I can go get materials

Enrique Chee
Enrique Chee6:43 PM

I only need 2 people . Alex and ? Alex please decide . Meet at Bhs at 11 am on sun.

Alex Larson Freeman
Alex Larson Freeman8:36 PM

I can take Kaedric since he was the first to respond, but all are welcome from 5-8 after the meeting

2017-01-08
Dana Batali
Dana Batali9:53 AM

Here's a link that discusses robot size and how the kop chassis has configs that are illegal https://www.chiefdelphi.com/forums/showthread.php?t=153134

Enrique Chee
Enrique Chee9:59 AM

Thanks

Enrique Chee
Enrique Chee10:01 AM

Good to see you are doing the students HW .:)

Dana Batali
Dana Batali11:16 AM

Happy to point students to some homework... The harder task, to read and consider the material, remains fully on their plates

Kenneth Wiersema
Kenneth Wiersema11:38 AM

Here's the plans for the team version of field elements, we might want to wait and see which strategy we're going with before building some of them. https://firstfrc.blob.core.windows.net/frc2017/Drawings/2017TeamVersions.pdf

2017-01-09
Jacob Barfield
Jacob Barfield9:46 AM

@Jacob Barfield has joined the channel

2017-01-10
Chris Rininger
Chris Rininger5:02 PM

I found this article I remembered reading years ago (I'm a bit of a basketball fan) - seems worth sharing given the similar problem to solve when optimizing high goal shooting. With the lighter weight of fuel balls shooting off of flywheels, I think the effect (perhaps opportunity?) of ball spin may also need to be considered. Enjoy! https://www.wired.com/2011/10/optimizing-a-basketball-shot/

Alex Larson Freeman
Alex Larson Freeman5:34 PM

2006 game! https://youtu.be/E7eEfWshXQ8

Chris Rininger
Chris Rininger11:21 PM

Just for fun, I created an illustration showing the parallels between the Wired article I shared earlier and the analysis required to try to optimize high goal shooting angle. If anyone wants to collaborate on this kind of analysis, let me know. Phun stuff!

2017-01-11
Chris Rininger
Chris Rininger8:58 AM

I have ideas about how to potentially analyze air drag (do we know terminal velocity of the 5" balls?) & Magnus effect from spin as well, but it seems like a good starting point to leave them out. Agree it's good to have a Physics teacher as coach:grinning:

Dana Batali
Dana Batali10:22 AM

this shows the "wide config KOP chassis" within the short robot volume (40" x 36"). No bumpers yet, but look at all the unused volume... This was a bit of a surprise to me and, if correct, suggests we may need to consider non-trivial modifications. Probably wise for a CAD student to check my work. The circle is a 5in ball. the dark big rectangle is max volume envelope. The chassis came from the Autodesk site referenced above.

Dana Batali
Dana Batali10:27 AM

here's a side view

Dana Batali
Dana Batali10:27 AM

(and yes, this model doesn't include bumpers)

Enrique Chee
Enrique Chee10:35 AM

Thanks !! I hope you students are reading this.

Dana Batali
Dana Batali12:08 PM

Aha... this is more like it... Bumpers are 3.25in thick. Corners are 6in... Now the wastage of the KOP chassis in wide config seems less-bad.

Will Hobbs
Will Hobbs12:08 PM

What is the square chassis like?

Will Hobbs
Will Hobbs12:09 PM

I have the square chassis file on fusion if you want it

Dana Batali
Dana Batali12:09 PM

i've got it too...

Dana Batali
Dana Batali12:10 PM

started with the wide chassis to maximize intake

Will Hobbs
Will Hobbs12:10 PM

Ok

Will Hobbs
Will Hobbs12:10 PM

I was thinking square u shape for more storage

Dana Batali
Dana Batali12:11 PM

were you thinking of the tall robot volume then?

Will Hobbs
Will Hobbs12:12 PM

Maybe

Will Hobbs
Will Hobbs12:12 PM

I need to take a closer look

Dana Batali
Dana Batali12:13 PM

in stratgroup2 we were concerned with the rate to fill the hopper, more than the hopper size... All these aspects now need to be re-evaluated in the context of different shooter and intake design ideas.

Riyadth Al-Kazily
Riyadth Al-Kazily12:58 PM

I echo the fact that we need to be able to fill the hopper quickly in order to be successful. It would be good to determine some goal rates for filling and shooting so that designs can be quickly iterated early on, rather than getting in deep before we find out something isn't fast enough.

Dana Batali
Dana Batali1:17 PM

@Will Hobbs : i just concluded that the square chassis with bumper won’t fit in the tall robot volume. Perhaps you or a CAD student should double check.

Will Hobbs
Will Hobbs1:17 PM

will do

Will Hobbs
Will Hobbs1:28 PM

I agree with your conclusion the tall option will not fit with the square chassis

Dana Batali
Dana Batali1:55 PM

both chassis within the short robot volume bumper (left is square, right is wide)

Brian Hilst
Brian Hilst9:24 PM

@Brian Hilst has joined the channel

Brian Hilst
Brian Hilst9:27 PM

One consideration about whether to orient the chassis for a wide vs narrow side forward is maneuverability. A wider robot may be harder to maneuver around other robots. Also, I think it will leave less room to add a gear slot on front or back. I know the motivation was to be able to pick up more balls, so we'll have to weigh the pros/cons.

2017-01-12
Dana Batali
Dana Batali9:00 AM

Chris Rininger
Chris Rininger10:23 AM

Here's a minimal volume climber design concept I came up with on the ferry this morning, for consideration in case we go there. Created in Powerpoint since I don't have (or know how to use) CAD :slightlysmilingface:.

Chris Rininger
Chris Rininger10:26 AM

Probably would not need to be that wide - maybe just wide enough for 3 hooks instead of 7 as shown

Dana Batali
Dana Batali1:22 PM

Here are highlights from the Aim High season. Before setting on a design, it's always a good idea to survey proven ideas of others. If any of these ideas tickles your fancy, you can find more details in Coach Chee's copy of the book.

https://docs.google.com/presentation/d/1cXsJKjMqGOQSAfSM9VHh4VYSxKZ2fNg1TS0bJYWCGrM/edit?usp=sharing

Dana Batali
Dana Batali1:22 PM

Dana Batali
Dana Batali1:24 PM

my focus here was on the interplay between intake, storage and shooting

Enrique Chee
Enrique Chee3:34 PM

Thanks for doing this. Again there are 3 opies of the book mentioned above.

Enrique Chee
Enrique Chee3:34 PM

copoies

Enrique Chee
Enrique Chee3:34 PM

copies, too much coffee !

Chris Rininger
Chris Rininger3:45 PM

Similar to what Dana shared, here is a "best of 2012" post on Chief Delphi that is very well done IMO. I think the high goal in that game is very similar to the high goal in this game from a shooting difficulty perspective. They had a larger, heavier ball (arguably more difficult than this year) but they also had things that made it easier like a functional backboard, a ball less susceptible to air drag and movement due to spin, etc. It would be good to look at the best high goal shooters' shooting mechanisms from that year. https://www.chiefdelphi.com/forums/showthread.php?t=106435

Chris Rininger
Chris Rininger3:53 PM

I just watched a match - wow that seesaw bridge was crazy!

Enrique Chee
Enrique Chee4:11 PM

It's great you Chris and Dana are so into it .

Dana Batali
Dana Batali4:50 PM

very good summary of 2012! (i skipped to page 5 to get the last-most-updated version of the list and links)

2017-01-13
Will Hobbs
Will Hobbs2:45 PM

I have the files but not with the bumpers

Dana Batali
Dana Batali2:47 PM

i can share or forward all my files, just haven't figured out the sharing features in fusion360

Will Hobbs
Will Hobbs2:48 PM

I can show you at the meeting today if you want

Dana Batali
Dana Batali2:53 PM

is it possible for me to share my spartronics project with all folks subscribed to spartronics, or is it more like I need to copy my project into spartronics?

Enrique Chee
Enrique Chee2:58 PM

Here a playlist of 8 of the 11 (3 day in robot reveal videos) in youtube that I created . I hope all have watched.https://www.youtube.com/playlist?list=PL-qLSGImlv5ScuC7Xtfr8KIzi8FwDGN8

Dana Batali
Dana Batali3:30 PM

coach - do you know if we have one of these from a previous kit of parts? https://www.amazon.com/Pixy-CMUcam5-Smart-Vision-Sensor/dp/B00IUYUA80 I do recall you mentioning that we have a pan/tilt system perhaps something like this: https://www.amazon.com/Tilt-Servo-Motor-Pixy-CMUcam5/dp/B00IVOEN1Y

Jack Stratton
Jack Stratton3:37 PM

napkin math, fuel volume `v = 5³ pi 4/3 = 523.599`, percent unused space for "pouring" balls in <https://en.wikipedia.org/wiki/Randomclosepack#For_spheres> = `39.1%`, 24x40x30" dimensions minus 7" each side for bumpers, `332918 = 17226in³` internal volume, assuming literally every inch is ball storage, `(17226 * (1-0.391)) / v` comes out to a hair over 20 fuel. that seems low, how does one actually calculate this? :)

Riyadth Al-Kazily
Riyadth Al-Kazily3:40 PM

@Dana Batali I'm fairly certain that we don't have the CMUcam (any version) in our inventory. I've looked into that camera in the past, and I think it's worth investigating.

Riyadth Al-Kazily
Riyadth Al-Kazily3:46 PM

@Jack Stratton I think there is something wrong with your volume calculation for a fuel ball. The 5" diameter ball will fit inside a cube of 5" edge, so the ball must have a smaller volume than (555)=125

Riyadth Al-Kazily
Riyadth Al-Kazily3:48 PM

Calculating how many 5" cubes would fit into 17226in^3 gives 137 (although the dimensions of the robot internal volume will probably clip some off of that by not accommodating an integer number of cubes in each dimension...)

Riyadth Al-Kazily
Riyadth Al-Kazily3:49 PM

Ah, I think the volume of the sphere is 4/3piR^3. The diameter is 5, so the radius is 2.5

Jack Stratton
Jack Stratton4:15 PM

ah, radius

Jack Stratton
Jack Stratton4:16 PM

178 balls makes more sense

Jeff Dalton
Jeff Dalton4:54 PM

Additional plywood outside building doors (flag pole). Can someone bring out into the lab?

Kenneth Wiersema
Kenneth Wiersema4:55 PM

The plywoods been brought inside now.

Declan Freeman-Gleason
Declan Freeman-Gleason5:31 PM

@Declan Freeman-Gleason has joined the channel

Niklas Pruen
Niklas Pruen5:52 PM

@Niklas Pruen has joined the channel

Enrique Chee
Enrique Chee9:23 PM

http://www.andymark.com/product-p/am-3516.htm, I bought 2 of these. Check the specs out. I will show On Sun.

Enrique Chee
Enrique Chee9:28 PM

Students in mechanics, you will be getting some research homework from your Captain (Will and Alex) on Sat. afternnon. Please do especially if you are on the team for school credit. To get class credit, various HW will be assign by me or the captains.

brian_bonifaci
brian_bonifaci10:20 PM

@brian_bonifaci has joined the channel

Enrique Chee
Enrique Chee11:41 PM

@Enrique Chee pinned a message to this channel.

2017-01-14
Chris Rininger
Chris Rininger12:00 AM

Another idea sketch: Goal is to optimize gear position to reduce gear cycle time

Enrique Chee
Enrique Chee12:12 AM

Thanks !

Chris Rininger
Chris Rininger10:27 AM

Elaborating on a concept I tried to convey at the town hall last weekend. Achieving high precision (different from aiming) may be the hardest engineering problem of high goal shooting to solve.

Will Hobbs
Will Hobbs10:28 AM

Thank you

Chris Rininger
Chris Rininger10:40 AM

No problem - I felt like I didn't really land the concept very well at the town hall. If you decide to try the testing platform at lower right in the image, I think it would be better for the ladder to be positioned at the center of the long side of the plywood after considering it a bit more. Folks, on all these posts I make, they're just ideas/concepts for consideration... use or discard them as you like :slightlysmilingface:.

Enrique Chee
Enrique Chee11:29 AM

Thank you for distinguishing the difference between precision and accuracy .

Will Hobbs
Will Hobbs3:18 PM

Bellow is the research homework that everybody must complete for tomorrows meeting. You will either be assigned to research the launcher or the intake of one of the robot in 3 day teams. Also everybody should look at the hopper system. Bring notes with the pros and cons of each design. Two of you will also be assigned to the 2006 game Aim High. If you have any questions feel free to ask.

@Harper Nalley : ri3d 1.0 launcher
@Sean Hooyer : Greenhorns RI3D launcher
@Parker Hutchinson : Snow problem Ri3d launcher
@Andrew Peterson : national instruments ri3d launcher
@Kaedric Holt : Tesla ri3d launcher
@Cruz Strom : Ri3d 1.0 intake
@Ashton Billmaier : Tesla ri3d intake
@Fiona Morrison : greenhorns ri3d intake
@Jacob Barfield : zou keeper ri3d launcher
@Rose Bandrowski : snow problem ri3d intake
@Robert Galvin : Aim high 2006 launcher
@Sophie Holzer : Aim high 2006 intake

You can find the ri3d reveal videos can be found here
https://www.youtube.com/playlist?list=PL-qLSGImlv5ScuC7Xtfr8KIzi8FwDGN8

Ashton Billmaier
Ashton Billmaier3:18 PM

@Ashton Billmaier has joined the channel

2017-01-15
Kenneth Wiersema
Kenneth Wiersema11:03 AM

Here's the spec/gear ratios for the tough box nano, for the highest Rpm configuration, we want the 5.95:1 gearbox. https://docs.google.com/document/d/1D3tw8TKgPdiBgzBvu2uBLtupzHnt0bGEg41KrOiHE

Kenneth Wiersema
Kenneth Wiersema11:03 AM

Will Hobbs
Will Hobbs11:03 AM

Thanks Kenneth

Will Hobbs
Will Hobbs11:12 AM

Let's make sure we have all of these gears during the meeting today

Dana Batali
Dana Batali11:15 AM

Does this get us to 3500 rpm or more?

Kenneth Wiersema
Kenneth Wiersema11:28 AM

No, using the no load rpm with the gear box gets us to 892 rpm, which goes to 15 ft/s with 4 in wheels. As the motor will have a load on it, I don't think that we're going to get 15ft/s out of it, I'm confident the robot speed will be greater than 10ft/s.

Alex Larson Freeman
Alex Larson Freeman12:19 PM

Interesting thread on game pieces, specifically fuel balls breaking down. We may need to account for this as field reset won't be able to replace all of the balls https://www.chiefdelphi.com/forums/showthread.php?threadid=153622

Dana Batali
Dana Batali12:31 PM

@Kenneth Wiersema I was imagining that you were talking about the flywheel, sorry for the confusion

Kenneth Wiersema
Kenneth Wiersema5:12 PM

The gear reduction for the gear boxes are 10.71:1 using a 16 and 48 tooth gear combination. We still should get 6 more 24, and 40 tooth gears, and 4 more of the 16 and 48 tooth ones.

Enrique Chee
Enrique Chee9:03 PM

@Kenneth Wiersema , remind me to show you the gear hex bore reduction from 1/2 to 3/8 inch for the gears. So we are building on Mon. 8.45:1 and we have all the gears for 4 gearboxes ? Please give Robert the orders for the gears. I want to put in an AM order by Mon afternoon.

Kenneth Wiersema
Kenneth Wiersema9:04 PM

Yes, we are building the 10.71:1, using the gears from the kop. Will has the information, so I assume it was passed on to Robert.

Will Hobbs
Will Hobbs9:05 PM

I am sending the email now

Enrique Chee
Enrique Chee9:18 PM

@Kenneth Wiersema , please make sure we put a note in both KOP chassis of which gears we took out and are using if you have not. Thanks

Kenneth Wiersema
Kenneth Wiersema9:19 PM

Of course

Enrique Chee
Enrique Chee9:23 PM

I will also order for 8.45:1 because High RPM will mean low torque and 5.95:1 might just be too low of a torque to move the robot.

Kenneth Wiersema
Kenneth Wiersema9:23 PM

Okay

Enrique Chee
Enrique Chee10:04 PM

40T 20DP 0.5" Hex Bore, Steel Gear (am-0178) , out of stock , only able to get 4 instead of 6. Remember everyone and their mother is ordering. SO PLEASE ASAP orders !!!!!!!

Enrique Chee
Enrique Chee10:08 PM

@Kenneth Wiersema @Will Hobbs , please go to AM and request email when the above gears are avaialble and let me know

Enrique Chee
Enrique Chee10:11 PM

should we order 6 vex omni or 6 inch AM omni ? Do we have 6 inch fro rear and type ?

Enrique Chee
Enrique Chee10:11 PM

for rear

Enrique Chee
Enrique Chee10:53 PM

I missed the drivetrain conversation two meetings ago. Just catching up with you mechanic engineers. How was 4 wheel ( 2 front omni and 2 rear tread wheel decided ) vs 6 wheel tank drive. Please see:

Enrique Chee
Enrique Chee10:53 PM

Enrique Chee
Enrique Chee11:03 PM

Again. Especially starting around pg .80. Maybe we should drive Atlas ( 6 wheel tank drive ) shorter wheelbase and compare to our current drivetrain of 4 wheels ( longer wheel base ). Will the omniwheel improve maneuvering? But make us more prone to being pushed around .

Enrique Chee
Enrique Chee11:23 PM

Great point !!!

Enrique Chee
Enrique Chee11:30 PM

Found 40 T gear in Vex.

Enrique Chee
Enrique Chee11:33 PM

people have been asking about specs. on motors. Please see this link: http://motors.vex.com/

Enrique Chee
Enrique Chee11:33 PM

@Enrique Chee pinned a message to this channel.

Enrique Chee
Enrique Chee11:58 PM

I have ordered both.

2017-01-16
Enrique Chee
Enrique Chee12:56 PM

Captains ? No answer? I ask cause by choosing our current configuration we just added about 10 hrs to our drivetrain assembly and chassis. Yes 10 hrs. (2 build sessions) Whatever drivetrain we finish assembling today will not be the final one and we still have to retrofit our chassis to fit the Toughbox nano and whatever u shape you guys decide. Lets see it on CAD before we physically assemble today. So be very mindful how each decision will affect the next. KISS !!

Kenneth Wiersema
Kenneth Wiersema8:28 PM

Do we need a second U shape chassis kit? And aside from the 6 6in wheels and the 2 pulleys is there anything else needed, since I can't think of anything else.

Will Hobbs
Will Hobbs8:30 PM

Whatever gears we used in the gearbox (Unless we have spares) and we do need another U shape chassis kit

Kenneth Wiersema
Kenneth Wiersema8:30 PM

The order that we did for the other gear boxes has the gears we need for the gearbox.

Will Hobbs
Will Hobbs8:31 PM

ok

Will Hobbs
Will Hobbs8:31 PM

just checking

Samantha Rosen
Samantha Rosen8:32 PM

I know that 4 of the CIM motors are going to be used for the drive train, but what of the other two?

Kenneth Wiersema
Kenneth Wiersema8:34 PM

Other modules, I would like to try to save one for the climber(if we get there), and the final one might go to storage/agitator?

Samantha Rosen
Samantha Rosen8:41 PM

What about the launcher?

Will Hobbs
Will Hobbs8:41 PM

a cim will not have a high enough rpm

Alex Larson Freeman
Alex Larson Freeman8:42 PM

We tried a CIM with the launcher and it worked

Alex Larson Freeman
Alex Larson Freeman8:44 PM

I think the agitator system would work with a window motor but I'm not sure

Enrique Chee
Enrique Chee8:57 PM

Right now . 1 cim for launcher. 1 for intake . 4 for geardrive . The climber will use the motor that we use from last year climber and stirrer not a cim

Kenneth Wiersema
Kenneth Wiersema8:58 PM

The motor we used last year for the climber was a cim with a 70:1 gearbox,

Enrique Chee
Enrique Chee10:13 PM

ok, then it would be the motor from Gaia that was use to lift the elevator system.

Enrique Chee
Enrique Chee10:13 PM

not CIM

Enrique Chee
Enrique Chee10:35 PM

What encoders are we using for the gearboxes ?

Lucas Rininger
Lucas Rininger10:50 PM

For the bumper team, I found this resource with some tutorials and resources http://www.robopromo.com/categorys/1825.htm

Enrique Chee
Enrique Chee11:07 PM

Thanks Lucas ! Are we going reverseable again ?

2017-01-17
Chris Rininger
Chris Rininger7:07 AM

It was great to see the progress on shooter prototyping yesterday! One thing I saw in a team video that I think might be useful: Get a long piece of pipe big enough for the balls to roll down (6" diameter will probably do, but 5" might be better) and use it to test different shooting rates. Like these this video: https://www.youtube.com/watch?v=Ezf6wL2WK8&feature=youtu.be&t=6m. The steeper the pipe, the faster the rate. I'm not sure if the prototype could be reconfigured to feed from the back, but that could help as well.

Chris Rininger
Chris Rininger7:17 AM

That whole video's worth watching actually - seems to be a Canadian RI3D team. The team has other videos as well, including a reveal: https://www.youtube.com/channel/UCFfnvW0xNabEDZy-nCEkg. They even subtitled the reveal for English speakers - here it is: https://www.youtube.com/watch?v=6HMjVVyCMI

Dana Batali
Dana Batali1:05 PM

great find!! A must-view for all engineers!

Dana Batali
Dana Batali1:09 PM

btw: this video calls in to question the idea that a gravity-fed solution isn't fast enough. Their tube shows that they can feed more that 5 balls/second. They do have accuracy issues, but that's likely to do with the fact that the wheel speed is too variable.

Dana Batali
Dana Batali1:13 PM

this robot also shows that the gear and the intake can both be on the same side (front) of the robot. This might be desirable for ease of driving as well as video-camera feedback (we'd only need one cam, not two)

Dana Batali
Dana Batali1:14 PM

also seems like they may have selected the small/square KOP chassis - this limits the volume of their robot, but probably made it esaier to complete in 100hours

Dana Batali
Dana Batali1:15 PM

also: @Bo Baird - check out 4:40 in this video https://www.youtube.com/watch?v=VojOpLciLM8

Bo Baird
Bo Baird5:50 PM

Thats cool. @Dana Batali I'm glad we didn't go with that idea now. They had a far superior prototype and it still didn't work as well as the roller intake.

Enrique Chee
Enrique Chee5:56 PM

fyi, I purchased this: http://www.andymark.com/product-p/am-3471.htm

Enrique Chee
Enrique Chee5:58 PM

This is one option for our bumpers. We can also customized our bracket system for the bumpers as we have in the past. Between this Lucas'posting about bumper http://www.robopromo.com/categorys/1825.htmand this kit , the bumper team have enough to work on. Bumper team ?

Lucas Rininger
Lucas Rininger5:59 PM

I can't tell based on the page whether or not this is meant to be used with reversible bumpers. It just says "can be used to make a set of red and blue bumpers" Can anyone tell one way or another?

Riyadth Al-Kazily
Riyadth Al-Kazily9:24 PM

Details of the field, in photographs.

2017-01-18
Lucas Rininger
Lucas Rininger10:48 AM

Does anyone know which file in our Fusion 360 is the current chassis configuration?

Lucas Rininger
Lucas Rininger10:48 AM

With the cut made

Will Hobbs
Will Hobbs10:49 AM

It has blue bumpers on it

Lucas Rininger
Lucas Rininger10:49 AM

ok, thanks

Dana Batali
Dana Batali6:43 PM

snow blower is: am-2235, window is: denso 262100-3030

Enrique Chee
Enrique Chee9:02 PM

for the intake team, instead of building rollers from scratch I suggest you look at Mcmaster

Lucas Rininger
Lucas Rininger9:02 PM

Thanks for the suggestion

Lucas Rininger
Lucas Rininger9:02 PM

I'll look into it

Enrique Chee
Enrique Chee9:02 PM

Let me know what will work so we can order. It takes about a week to get from Mcmaster.

Enrique Chee
Enrique Chee9:09 PM

Also for those on the intake team (Sophie, Fiona, Ashton, Lucas) please do research on which polycord we want, texture ? diameter (based on minimum pulley size), hollow vs solid, Let me know by Friday so I can order.

Enrique Chee
Enrique Chee9:14 PM

Forgot Andrew in intake for CAD

John Sachs
John Sachs9:32 PM

Pretty good thread on chief Delphi; suggests using flat Polycord: https://www.chiefdelphi.com/forums/showthread.php?t=153426&highlight=Polycord

Lucas Rininger
Lucas Rininger9:47 PM

Thanks John!

Enrique Chee
Enrique Chee9:54 PM

Launcher group: Do we want to do some more prototyping on different flywheels ? Currently we are using green Banebot wheels (about 6 inches) . Those green wheels will wear out easily and will need to be replace. We only have 2, so we may need to order more. How about some research on CD for the best and different types of wheel for the fly wheel ? Check out AM, and Banebots site.

Enrique Chee
Enrique Chee9:59 PM

check out this site for video and robots parts

Enrique Chee
Enrique Chee10:15 PM

back to intake options for rollers:

Enrique Chee
Enrique Chee10:16 PM

2815 used polycord in 2009 and 2012. Both times, we used some ABS or Delrin rod from McMaster, cut the necessary grooves on a lathe, then broached it for 1/2" hex.

Enrique Chee
Enrique Chee10:16 PM

2nd option: We used a lathe to throw some grooves onto these. http://www.andymark.com/product-p/am-1305.htm

Nowadays I'd just 3d print them

Enrique Chee
Enrique Chee10:20 PM

@Lucas Rininger , you can stick to your original hex bar and and use the above hex spacers which we have a few (we need more). http://www.vexrobotics.com/shaft-stock.html , I ordered some already.

Enrique Chee
Enrique Chee10:23 PM

FROM John again. Do your HW and read !!!! Intake team and captains.

Enrique Chee
Enrique Chee10:27 PM

or simply use pvc as rollers and cut some grooves and use these bearings

Enrique Chee
Enrique Chee10:36 PM

Green wheels are 4 7/8 inch not 6 inch. Green means ? Durometer scale , the softest. Do research on what durometer means and report back about color and meaning ?

Enrique Chee
Enrique Chee10:57 PM

We need to order some polycarbonate from online metal of various thickness to bend for launcher and for the hopper box.

Enrique Chee
Enrique Chee10:58 PM

Someone please give me order ASAP from http://www.onlinemetals.com/merchant.cfm?id=270&step=2&topcat=181

Enrique Chee
Enrique Chee10:59 PM

20% sale till Friday from onlinemetals.com

Enrique Chee
Enrique Chee11:11 PM

What should we use as our base for our electronics this year ?

Enrique Chee
Enrique Chee11:53 PM

Nevermind on the online metal order request. Done.

2017-01-19
Enrique Chee
Enrique Chee12:06 AM

We have a $40 voucher from Inventables ? What do we need ?

Chris Rininger
Chris Rininger10:18 PM

I happened to be around the evening they traded the mini cim for the full cim on the shooter prototype and saw a significant improvement in flywheel rpm recovery time after each ball shot. Lucas has told me a cim won't be needed for the intake motor, nor will one be needed for the climber, which I think means there is one cim left to use. A hypothesis worth testing might be that the flywheel rpm recovery time could be improved even more by using two cims to drive the flywheel... If the hypothesis were proven true, it would allow for shooting at a faster rate and/or with greater precision due to less falloff, either of which would improve effectiveness. Regarding testing with another more resilient wheel, could be worth doing if the current soft-surface wheel will require frequent replacement due to wear.

Riyadth Al-Kazily
Riyadth Al-Kazily10:21 PM

Do we need to run the launcher CIM at 100%? I am hoping not, since battery drop will result in shorter shots at the end of the match. If we are not at 100%, then the inclusion of an encoder on the launcher shaft will allow the motor controller to perform PID speed control, resulting in much faster speed recovery after each shot.

Chris Rininger
Chris Rininger10:23 PM

It was not running at close to 100% I don't think, but others will know for sure. Question: is it a viable idea to run two CIMs on one wheel (wire serially maybe). I still have a lot to learn about those motors.

Chris Rininger
Chris Rininger10:36 PM

Also on shooter, GREAT points from user
Ekcrbe (post 4) in this thread: https://www.chiefdelphi.com/forums/showthread.php?threadid=153955

2017-01-20
Riyadth Al-Kazily
Riyadth Al-Kazily7:50 AM

It is fine to couple two CIMs mechanically together. That's how the drivetrain is powered - the CIMs are driving the same gears, and cannot spin independently. In this configuration, we would run two motor controllers together, either with one in "follower" mode (CAN Talon), or just splitting the PWM control cable to control two standard speed controllers. But still, you'll get better bang for your buck by adding the encoder and letting the control system do the work of maintaining shooting speeds.

Dana Batali
Dana Batali10:09 AM

@Riyadth Al-Kazily : the thinking in the launcher programming subteam is that we'd run in constant velocity control mode... For this to work at all we'd definitely not be running/targeting 100% VBus in order to have extra juice to recover. There is a target RPM that we need the flywheel to spin at, so it's possible that a gearing stage would need to be introduced to balance all this out.

Enrique Chee
Enrique Chee1:14 PM

see this video, another robot reveal

Harper Nalley
Harper Nalley2:09 PM

Indiana seems to have a robot somewhat similar to ours, that bodes well.

Will Hobbs
Will Hobbs2:12 PM

But they are not very accurate

Kenneth Wiersema
Kenneth Wiersema2:56 PM

Indiana couldn't shoot, and what I thought was a launcher would be inaccurate.

Clio Batali
Clio Batali9:13 PM

Hey guys! For anyone interested in thinking about the scaler and what something like that might look like, head over to #climber for some brainstorming and discussion. If you have ideas, that's the place to post them!

Enrique Chee
Enrique Chee9:27 PM

Enrique Chee
Enrique Chee9:29 PM

intake, hopper, launcher, gear grabber (passive), climber

2017-01-21
Enrique Chee
Enrique Chee2:01 PM

FYI reminder again from FIRST: A quick heads up – for the first time in my experience with FIRST, this year’€™s sizing of your robot INCLUDES the required bumper assemblies! What this means is that when your robot is inspected, the maximum volume specified in R03 of the Game Manual will include the bumpers required by Section 8.5 of the Game Manual! Plan accordingly!

Further, the maximum volumes indicted in R03 and shown in the Figure at G04 enclose the dimensions your robot can extend to. That means if you have scoops, funnels, lips on hoppers, etc. that are contained within your frame perimeter at the start of the match (as they must be by R02), these items can extend no further than the bounds of the indicated maximum dimensions. You are advised to built your robot smaller than the volume in order to give your extensions room to expand beyond your bumpers, if necessary, after the start of the match.

Don’t think of these volumes as the size to which you need to cut your chassis!

Start thinking NOW about your bumpers. As soon as you assemble your chassis frame, go ahead and cut your plywood bumper backing and attach it to the chassis. That way, you will know how your bumpers will be attached, what spaces you have to work with, and where you can attach other robot components.

2017-01-22
Chris Rininger
Chris Rininger12:36 PM

interesting thread on how much power teams are allocating to different systems: https://www.chiefdelphi.com/forums/showthread.php?t=153965

Enrique Chee
Enrique Chee7:56 PM

@Enrique Chee pinned a message to this channel.

Enrique Chee
Enrique Chee7:59 PM

CNN folks with X-carve. We have a $40 voucher. Do we need something ? https://www.inventables.com/

Lucas Rininger
Lucas Rininger8:00 PM

What is the RPM of our drive train? Asking for intake gearing. Apparently our intake should be geared twice as fast as our drive train.

Kenneth Wiersema
Kenneth Wiersema8:01 PM

Posted this a while ago: Just thinking about the cnc, here's a replacement waste board that I found https://www.inventables.com/technologies/waste-board-with-threaded-inserts we would want the 1000mm board. Just thinking whether we want to replace the waste board or not.

Lucas Rininger
Lucas Rininger8:04 PM

Correction on my previous comment. The intake should be geared to move twice as fast as you expect your robot to be moving

Lucas Rininger
Lucas Rininger8:04 PM

Do we have a rough estimate of that yet?

Kenneth Wiersema
Kenneth Wiersema8:05 PM

The gear ratio is 8.45:1

Lucas Rininger
Lucas Rininger8:06 PM

What does that bring the output rpm to with 2 cims?

Kenneth Wiersema
Kenneth Wiersema8:07 PM

Not sure with the two cims, but I was getting 471 rpm with cims running at 75% power

Lucas Rininger
Lucas Rininger8:08 PM

Thank you

Riyadth Al-Kazily
Riyadth Al-Kazily9:31 PM

@Kenneth Wiersema How were you measuring RPMs on the CIMs? And I assume that 75% power was based on the motor controller PWM, correct?

Kenneth Wiersema
Kenneth Wiersema9:32 PM

I was using the specs found on the websites, I haven't done any actual measurements

Riyadth Al-Kazily
Riyadth Al-Kazily9:32 PM

I ask because CIMs should run at above 5000rpm unloaded, and your measurement is an order of magnitude smaller. Maybe it's on the output of the 8.45:1 gearbox that you measured 471?

Enrique Chee
Enrique Chee9:33 PM

I dont think we anotherwaste board.

Riyadth Al-Kazily
Riyadth Al-Kazily9:34 PM

OK, that makes some sense. But I expect that with any load at all, your RPM out of the motors will be significantly reduced. Friction of the gearbox will slow it down quite a bit by itself.

Kenneth Wiersema
Kenneth Wiersema9:35 PM

Yes, 75% of 5310 is 3982, and 3982 divided by 8.45 is 471

Kenneth Wiersema
Kenneth Wiersema9:35 PM

I didn't measure anything, I did some math with the specs

Riyadth Al-Kazily
Riyadth Al-Kazily9:35 PM

Got it. OK!

Lucas Rininger
Lucas Rininger9:36 PM

The actual question that needs an answer is the ground speed of the robot. This is because when the speed of the intake is <2x the speed of the robot, the balls will bounce off rather than get sucked in

Lucas Rininger
Lucas Rininger9:36 PM

Is there a solid way to measure that?

Lucas Rininger
Lucas Rininger9:37 PM

I if there is, then measuring it when the weight of the robot is the lowest it will possibly be would be ideal

Riyadth Al-Kazily
Riyadth Al-Kazily9:37 PM

Ground speed of the robot will be limited by the ability of the drivers, more so than the motors. But Kenneth's computations give you an absolute maximum speed.

Lucas Rininger
Lucas Rininger9:38 PM

Because the speed of the intake needs to be at least twice the ground speed of the robot

Riyadth Al-Kazily
Riyadth Al-Kazily9:38 PM

We would have to put the chassis on the ground with some weight on it (to represent the finished bot) and run it over a distance while timing it.

Lucas Rininger
Lucas Rininger9:38 PM

So doubling up on the speed when the robot is light would give some room for error

Riyadth Al-Kazily
Riyadth Al-Kazily9:38 PM

Remember, the driver can slow down (or programmers limit the speed) while collecting balls.

Lucas Rininger
Lucas Rininger9:39 PM

True- i doubt that we'll be driving full speed while intaking balls

Kenneth Wiersema
Kenneth Wiersema9:39 PM

Just calculate the circumference of the wheel and multiply that by the rpm and do a few unit conversions to get the ideal ground speed, and reduce it by what ever amount you think is appropriate

Riyadth Al-Kazily
Riyadth Al-Kazily9:39 PM

I guess the question is, what should the speed of the robot be while collecting balls? Maybe we can estimate that based on how many balls we want to collect in how much time..

Will Hobbs
Will Hobbs9:39 PM

With the current gear reduction you are supposed to get 12.7 ft per second

Will Hobbs
Will Hobbs9:39 PM

Max speed

Alex Larson Freeman
Alex Larson Freeman9:40 PM

I'm just gonna jump in and say I don't want to collect balls at max speed

Lucas Rininger
Lucas Rininger9:40 PM

Ok, ideally we want to be able to intake while going at our max speed, because time is everything. I'm going to use that estimate to decide on the gear reduction for the intake

Lucas Rininger
Lucas Rininger9:41 PM

Not always intake balls at max speed, but have the ability to

Alex Larson Freeman
Alex Larson Freeman9:41 PM

ok that sounds good then

Riyadth Al-Kazily
Riyadth Al-Kazily9:42 PM

If we have a 'best speed' for collecting balls, we can have the programming team make a mode of the drivetrain where it can't go over that speed. (Override-able by the driver)

Lucas Rininger
Lucas Rininger9:43 PM

Question- would "ideal" speed of the intake = pidiameter of shaftrpm?

Lucas Rininger
Lucas Rininger9:44 PM

Rather, would that be how you would calculate the speed of the intake

Lucas Rininger
Lucas Rininger9:44 PM

then set that equal to twice the ft/s of the robot

2017-01-24
Chris Rininger
Chris Rininger7:26 AM

@Alex Larson Freeman I remembered this question & answer:
Paul Vibrans [10:43 AM]
What is the shooter's angle from the vertical for hitting the high goal from right in front of the…
Alex Larson Freeman [11:52 AM]
About 8.3 degrees from the vertical

I wanted to double check: Is that the angle assuming the shooting mechanism is butted up against the boiler? If the shooter is at the rear of the robot, will the angle need to be a bit less steep?

Chris Rininger
Chris Rininger7:31 AM

Request: If you have a few minutes (study break?), please go to the climber channel (join if you haven't already!) & help crowdsource the pre-design analysis. There's a Google sheet in which knowns, requirements, & solution options are being captured. Thanks!!!

Enrique Chee
Enrique Chee4:32 PM

Enrique Chee
Enrique Chee4:32 PM

Chris R. recommended this for our pits. and maybe our robotic room. If someone is interested please research in Amazon and send me link for pricing .

2017-01-25
Chris Rininger
Chris Rininger6:24 PM

I saw this CD thread a while back, and it seems like there are some tips & recommendations that could be helpful: https://www.chiefdelphi.com/forums/showthread.php?threadid=153999

Lucas Rininger
Lucas Rininger6:56 PM

Ideas for mounting a motor/gear reduction to drive this shaft?

Lucas Rininger
Lucas Rininger6:57 PM

Lucas Rininger
Lucas Rininger6:58 PM

2017-01-29
Chris Rininger
Chris Rininger11:35 AM

Climber update: team update 5 clarified that Velcro is absolutely usable and a loop around the davit fingers may be used as a retaining feature. reposting some things from the climber channel here - the net is that while LIA is current top priority, reserving space for the climber is a requirement for LIA - this is my opinion - see below...

Chris Rininger [10:52 AM]
With these and other clarifications, they have really made climbing doable. The most prominent field pieces are the airships - even in district matches they want the spectacle of robots ascending for takeoff! And so they're making it doable. I thought the hard part was going to be connecting the robot to the rope, but Velcro works for that. Now I think the hardest part is stopping at the top so there is sustained pressure on the plate (without burning out the motor & without breaking the dang plate). From looking at Chief Delphi, I believe over 90% of teams will attempt to climb and I believe over 50% of teams will be able to do it reliably - too many points to leave them on the table - better believe teams are investing in this. I personally view this as a must-have. Viva la escalador! (edited)

Enrique Chee [11:17 AM]
Good to see you are reading rules. Hope the students are . Again, I agree about having a climber but the priority is LIA right now .

Chris Rininger [11:28 AM]
agree... just need to reserve some volume somewhere on the robot for the climber... can't afford to achieve LIA in a way that prevents climber IMO - should be on the list of requirements for LIA

James Sovick
James Sovick12:18 PM

But you also have to account for the weight of everything. Mr Chee was talking to everyone yesterday about the weight of the robot and with all the things were putting on the robot it's probley going to be close.

Enrique Chee
Enrique Chee6:06 PM

If we cut with Michaels CNC on mon , you guys need to get the wood out of the robotic room and store it in the hallway outside my class . Please do asap .

2017-02-03
Chris Rininger
Chris Rininger10:06 AM

Comments welcome. If overall robot designers have ideas about potential locations for the climber & associated volume constraints, that will really help the team working on this prepare for next steps - very likely a 2nd prototype closer to the final design will need to be built & tested

Dana Batali
Dana Batali10:07 AM

curious what the implications of this placement are for driving/approaching the rope

Chris Rininger
Chris Rininger10:10 AM

yes, definitely a consideration

Alex Larson Freeman
Alex Larson Freeman10:13 AM

That version of the CAD doesn't include a final gear holder, so that's going to take up some of the space along the back of the frame

Alex Larson Freeman
Alex Larson Freeman10:13 AM

But I like the placement, we should make sure no electronics are going there before we make a decision

Alex Larson Freeman
Alex Larson Freeman10:15 AM

From a driver perspective, it would be nice to have the gear side camera on the same side as the climber so it's easier to line up

Chris Rininger
Chris Rininger10:17 AM

If the climber is low there might be a way to place a visual reference higher up on the robot for drivers to use to "aim" the robot at the rope

Alex Larson Freeman
Alex Larson Freeman10:18 AM

In the past we used a small flag from a bike, maybe something similar?

Chris Rininger
Chris Rininger10:18 AM

something like that - maybe a little yellow propeller

Alex Larson Freeman
Alex Larson Freeman10:18 AM

Yeah that would be perfect

Chris Rininger
Chris Rininger10:22 AM

if need that spot for gear (because there needs to be open space behind for the spring to thread through), then could look at one of the corners on the intake side as well - they seem like pretty small spaces though

Alex Larson Freeman
Alex Larson Freeman10:26 AM

Not sure you'd have enough room there but we can probably make the back corner work

2017-02-04
Chris Rininger
Chris Rininger9:50 PM

Interesting thread on CD about maximizing shooting rate... there are a lot of advocates of increasing flywheel mass (along with closed loop control). One recommendation I thought was good (in post 10) was to set up gearing so the motor rpm at shooting speed is around 60%, allowing controller to spike power for recovery after each shot. https://www.chiefdelphi.com/forums/showthread.php?threadid=154712

Dana Batali
Dana Batali10:44 PM

fyi - this is more or less our plan without specific percentages for recovery rate... good to hear we're not on a bad path

2017-02-05
Chris Rininger
Chris Rininger10:08 PM

Hi, I was going to look at the "final" F360 assembly because Bo told me some volume is now reserved for the climber, but I can't seem to open the file - says it is in the middle of saving, & it also fails when I try to open a past version. Any advice?

Chris Rininger
Chris Rininger10:19 PM

Also, from a link to FRC2877's pictures of the Steamworks unveiling that Riyadth shared, I copied some key pictures of the gear spring and lift.

Alex Larson Freeman
Alex Larson Freeman10:32 PM

It is probably failing to open because someone else is saving the file or is editing it

Alex Larson Freeman
Alex Larson Freeman10:33 PM

You can try just waiting for it to update locally, the latest version may already be saved but not on your computer yet

Chris Rininger
Chris Rininger10:56 PM

Will Hobbs
Will Hobbs11:05 PM

My guess is someone shut off their CAD staton today while the file was still saving when you do that fusion has issues

Chris Rininger
Chris Rininger11:05 PM

ah, makes sense - Lucas said something like that also - thnaks

2017-02-07
John Sachs
John Sachs9:39 PM

Was anyone able to clean up and finish the CAD over the snow days? Seems like there are still open questions that will slow us down if not dealt with soon. Like how are all the currently freestanding posts tied together to make a stiff and solid structure? Mounting of the climber? And finalizing the details of the intake, like the curved backplate?

John Sachs
John Sachs9:39 PM

At tomorrow's meeting, do we need to go team by team and detail how we get to done? Maybe team leads can come to the meeting with a starting list?

Enrique Chee
Enrique Chee9:43 PM

Great suggestion ! I we repost in leadership .

Enrique Chee
Enrique Chee9:46 PM

Bo ? Will ? Alex ? CAD ?

Enrique Chee
Enrique Chee9:46 PM

Lucas ?

Alex Larson Freeman
Alex Larson Freeman9:46 PM

I haven't been able to finish what I was doing but hopefully I can get it done before the meeting tomorrow

Lucas Rininger
Lucas Rininger9:46 PM

I'm in the same boat

Enrique Chee
Enrique Chee9:47 PM

What have you been doing ? 2 extra days of no school !!

Alex Larson Freeman
Alex Larson Freeman9:50 PM

the file is currently being saved by one of the CAD computers which was not shut down properly

Alex Larson Freeman
Alex Larson Freeman9:50 PM

so we can't edit it

Enrique Chee
Enrique Chee10:06 PM

WHAT !!!!

Enrique Chee
Enrique Chee10:10 PM

Why did you not mention this so we could have gone to school and correct this problem ?

Enrique Chee
Enrique Chee10:12 PM

There must be a way around this CAD issue. Bo ? Will ?

Will Hobbs
Will Hobbs10:14 PM

I do not know of a way around it

Alex Larson Freeman
Alex Larson Freeman10:16 PM

I just found a way

Enrique Chee
Enrique Chee10:16 PM

I don't know why you or Alex did not suggest going to school the last 2 days and correct this .

Alex Larson Freeman
Alex Larson Freeman10:16 PM

We can work off version 40 of the assembly which is the latest one to be saved properly. Versions 41 and 42 are mid-save

Alex Larson Freeman
Alex Larson Freeman10:18 PM

If I remember correctly those two versions are only different in that they include some climber parts and the agitator system I was working on

Alex Larson Freeman
Alex Larson Freeman10:19 PM

but that agitator system is built elsewhere and can be dropped into the assembly

Enrique Chee
Enrique Chee10:20 PM

Who was working on the climber part ?

Alex Larson Freeman
Alex Larson Freeman10:20 PM

Bo and Chris R

Enrique Chee
Enrique Chee10:21 PM

Bo ?

Will Hobbs
Will Hobbs10:21 PM

I was not aware it was an issue again

Alex Larson Freeman
Alex Larson Freeman10:22 PM

Neither was I until earlier today but it looks like it's not too bad

Alex Larson Freeman
Alex Larson Freeman10:22 PM

the climber CAD was mostly blocking out space

Will Hobbs
Will Hobbs10:23 PM

Tommorow we need to go over how to save everything properly so we do not have this issue again

Enrique Chee
Enrique Chee10:24 PM

Chris our mentor posted back on Sun. pointing a problem. Did you guys not think about a solution. See his post and yours (Alex on Sun) .

Enrique Chee
Enrique Chee10:25 PM

Will, you also commented back on Sun.

Alex Larson Freeman
Alex Larson Freeman10:25 PM

I didn't think to roll back the version, no

Alex Larson Freeman
Alex Larson Freeman10:25 PM

that was a mistake on my part

Enrique Chee
Enrique Chee10:27 PM

Alex Larson Freeman
Alex Larson Freeman10:28 PM

This is exactly what I see now. By opening v40 the file will work.

Enrique Chee
Enrique Chee10:28 PM

Ok, lets see what can be done before our meeting on Wed.

Alex Larson Freeman
Alex Larson Freeman10:30 PM

I think we should also go over making separate assemblies then dropping them into the main robot assembly rather than always working off of the final robot. This would make it way easier for us to share files without overwriting each other.

Alex Larson Freeman
Alex Larson Freeman10:30 PM

The agitator is built this way, so I can drop in the parts I'm working on whenever

Enrique Chee
Enrique Chee10:31 PM

Maybe contact Parker and Andrew. Parker was not there on Sun. Looks like Parker was messing with it. and Andrew version 42.

Alex Larson Freeman
Alex Larson Freeman10:31 PM

It's also possible they were never logged out of their computers

Enrique Chee
Enrique Chee10:31 PM

V41 by Bo ?

Alex Larson Freeman
Alex Larson Freeman10:31 PM

no clue what happened there

Alex Larson Freeman
Alex Larson Freeman10:33 PM

I will see what I can do before the meeting tomorrow. Signing off for the night.

2017-02-08
2017-02-09
Chris Rininger
Chris Rininger7:30 AM

Chris Rininger
Chris Rininger7:33 AM

In the next meeting or two the team will be making design decisions about the final climber for the robot (as soon as we know location/volume constraints). If you want to be in on that, please join the climber channel if you have not already AND please review the "All Things Climber..." compilation of rules and Q&A answers I created.

Chris Rininger
Chris Rininger7:34 AM

@Paul Vibrans Please see above

Bo Baird
Bo Baird5:01 PM

Thanks Chris!

2017-02-10
Chris Rininger
Chris Rininger9:38 PM

Quick question: Given the functions on the robot this year, how well are people thinking the battery is going to hold up by the last 30 seconds when it is time to climb? Paul mailed me his assumptions and calculations about the climber motor, etc. including projecting an optimal gear ratio, and one of his assumptions is the battery will be somewhat low on power by climbing time. Just testing that assumption. Thanks

2017-02-11
Chris Rininger
Chris Rininger12:14 PM

While analyzing the climber I learned that many teams use JVN's Mechanical Design Calculator as they work on design of motor-powered robot mechanisms. It basically includes all the FRC motors, data from tests of the motors, and frameworks for different mechanical scenarios using the motors you can plug into. Here's the latest one from early 2016.

Chris Rininger
Chris Rininger8:18 PM

Related: Paul's comment about battery drain made me curious, and I've been reading a bit about batteries, the need to test (including drain patten) them regularly, and also some stories about batteries having some cells not working optimally after impacts (seems like there were a lot of impacts last year via defenses). What's the team's battery management/test/refresh approach?

2017-02-15
Chris Rininger
Chris Rininger9:53 AM

I want to raise a risk related to the climber... With the location of the climber being the corner at the chassis level, we need to think about (& we'll need to test) how the robot will tip up & how it will hang (& potentially swing). I think there's a fair risk that the opposite corner of the robot, specifically the top of the intake, will contact the ground. It is possible we'll need to structurally reinforce that part of the robot, and I would not recommend locating anything (e.g. camera, wireless tranceiver, etc.) potentially sensitive to impact in that area either. The climber may climb fast enough that this risk doesn't turn into an actual issue, but when I visualize the climb in my head I do see an impact - just not sure how forceful.

Alex Larson Freeman
Alex Larson Freeman11:46 AM

Right now the radio and the RSL are going to be located at the opposite corner from the climber

Alex Larson Freeman
Alex Larson Freeman11:48 AM

Those can be moved but right now the part of the robot that is most likely to be damaged is probably the intake, since if it gets out of alignment it will not work, whereas the radio and RSL can still function if they are knocked around

Terry Shields
Terry Shields7:37 PM

@Terry Shields has joined the channel

2017-02-18
Conrad Weiss
Conrad Weiss9:08 AM

@Conrad Weiss has joined the channel

2017-03-14
Alex Larson Freeman
Alex Larson Freeman5:19 PM

Alex Larson Freeman
Alex Larson Freeman5:23 PM

Launcher: Kenneth and Rose
Agitator: Jack C and Julian
Intake: Lucas R and Fiona
Climber: Conrad and Samantha
Gear: Sophie and Andrew
Bumpers: Robert and Lucas N
CAD: Bo and Kaedric
Electronics/Pneumatics: Adrianna and Peter

HELIOS: Cruz
ATLAS: James S

James Sovick
James Sovick5:25 PM

Sovick or Slattery?

James Sovick
James Sovick5:26 PM

Nevermind.

Alex Larson Freeman
Alex Larson Freeman5:27 PM

It's you

Alex Larson Freeman
Alex Larson Freeman5:27 PM

Go fast

James Sovick
James Sovick5:27 PM

Sanic fast?

Alex Larson Freeman
Alex Larson Freeman5:31 PM

Faster

John Sachs
John Sachs7:13 PM

Uh, room plan for open house looks crazy crowded. I'm trying to imagine 60+ visitors in that space, which is smaller than Mr. Chee's room. Any way to move bumpers and climber out to hallway or another room? Then you would have more circular flow. Just a suggestion....

2017-03-15
Finn Mander
Finn Mander2:26 PM

@Alex Larson Freeman should I help with the agitator?

Alex Larson Freeman
Alex Larson Freeman2:29 PM

looks like you're selling t shirts but you can negotiate with Jack Chapman or Julian to trade

Finn Mander
Finn Mander3:11 PM

Ok! Thanks

2017-03-19
Andrew Peterson
Andrew Peterson11:13 AM

I will not be able to make it to the meeting today due to a sickness that I picked up yesterday

2017-03-22
Ethan Rininger
Ethan Rininger10:11 PM

@Ethan Rininger has joined the channel

2017-04-23
Rose Bandrowski
Rose Bandrowski9:27 AM

Hey guys, I never got Fusion 360 on my computer and I wanted to try tinker with it but the autodesk site is being rude and not letting me download the free student version, how should I go about getting it?

James Sovick
James Sovick9:29 AM

How is it not letting you download it?

Rose Bandrowski
Rose Bandrowski9:30 AM

It's like log into the site and you can download it but when I log in it just keeps saying the same thing lol

Rose Bandrowski
Rose Bandrowski9:30 AM

And I signed into it as a student

James Sovick
James Sovick9:30 AM

Did you verify the account

Rose Bandrowski
Rose Bandrowski9:31 AM

...maybe?

Rose Bandrowski
Rose Bandrowski9:31 AM

I'll check

Rose Bandrowski
Rose Bandrowski9:33 AM

Okay I stupid it needed me to verify something (to my credit, they weren't being clear). Thanks sovick

James Sovick
James Sovick9:34 AM

No prob

2017-04-24
Kaedric Holt
Kaedric Holt10:39 PM

I can help if you need help actually using it.

2017-05-02
Chris Rininger
Chris Rininger10:10 PM

One of my robotics photography projects this year involved gathering ideas for custom robot controls & drive station. Here's a collection of pictures from district champs and worlds. I really like the ones that are modular in that they keep the same drive station from year to year, but a section of the drive station is a robot control module specific to that year's game. Each year - new game - new control module. Some of the controls at worlds were really slick, and from talking with the teams that created them, the projects to create the custom controls were surprisingly doable. Hope y'all like these :slightlysmilingface:. https://1drv.ms/f/s!AikCDwtdoW5Lqj66386jgdCOtXj

Chris Rininger
Chris Rininger10:39 PM

here's the Customer Control Interface (CCI) several of the teams used - there are probably others... https://www.estoprobotics.com/estore/index.php?a=viewProd&productId=33

2017-05-03
Dana Batali
Dana Batali8:33 AM

i've built a few devices around this processor: https://pjrc.com/teensy/index.html

at around $12 each, I think its a far better deal. Perhaps there are differences that justify the extra $28 - i didn't deeply peruse the spec.

2017-05-04
Chris Rininger
Chris Rininger8:29 PM

Closing out 2017 robotics photography projects. Here's a set of high performing shooting robots from Houston. This could be helpful to the summer BARN project... https://1drv.ms/f/s!AikCDwtdoW5LrRy1-yYJ9ExJlWAk
Of course, it would be a good idea to also check out online pictures of the top St. Louis shooters. :slightlysmilingface:

2017-05-06
Chris Rininger
Chris Rininger2:51 PM

Speaking of St. Louis, here's a high res pic (you can zoom in to see up close) of 254's bot: https://media.team254.com/2017/03/902d07bd-misfire.jpg

2017-05-20
Chris Rininger
Chris Rininger11:45 AM

Per Rose's suggestion, copying this here from marketing
I was looking for a contact on Chill Out to send some pictures I took during the Worlds quarterfinals we shared with them, when I ran across this Facebook post on their page from someone on the Skunkworks team. Considering the fact that our team has learned quite a bit from Skunkworks, from their pre-season workshops & other interactions, I think it would be a good thing for a couple students to write supportive emails as requested. Here's the post:

Thomas DeSilva (May 2 at 10:11pm)
Skunk alumni, family, and friends of the team:
We need your help. For those of you who haven't been in the loop, we've had a rough year. We no longer have the same amount of support we once had, chiefly from the school's and the district's administrators. We need to show them the value that our team has to our students and to our community, and we need your help to do it. If you're an alumnus, a parent, a mentor, a FIRST volunteer, a member of another team, or anyone else with a story to tell, please leave us a note (or an essay!) at . Tell us who you are and about the positive impact that our team had on you. It doesn't need to be long; we know that you're busy and we appreciate anything you can do for us.
Please try to let other people know about this--especially those whom I'm not connected with or aren't on Facebook at all--as it's important. There's a lot on the line here. We want to hear from you.
We need to hear from you.
Thanks for reading, and remember: "Once a skunk..."

2017-06-07
2017-06-15
2017-06-21
2017-06-23
Bo Baird
Bo Baird8:19 AM

Thats amazing!

Enrique Chee
Enrique Chee9:30 AM

Dana, thanks for sharing.

2017-07-08
Paul Vibrans
Paul Vibrans11:13 AM

@Paul Vibrans has joined the channel

2017-07-13
Alex Larson Freeman
Alex Larson Freeman4:05 PM

Alex Larson Freeman
Alex Larson Freeman4:05 PM

2017-07-28
Chris Rininger
Chris Rininger11:55 AM

Cool! It looks to me a little like a flying transformer. Structures that expand/contract like this seem to be a trend. I heard on NPR a couple days ago about a space station module being tested that is compressed during launch and then expanded once in space.

Rose Bandrowski
Rose Bandrowski4:19 PM

Thats so cool oh my gosh I love this idea

2017-08-04
Harper Nalley
Harper Nalley9:17 PM

The future of mobile homes looks good.

2017-08-05
Bo Baird
Bo Baird12:13 AM

True!

Bo Baird
Bo Baird12:16 AM

What impressed me was the quality of the space despite its extreme capability for compactness. To relate to what you said lucas_nalley I think this puts RV's to shame.

Harper Nalley
Harper Nalley2:52 PM

Yay! No more caravanists!

Bo Baird
Bo Baird6:54 PM

I just wish they looked better. The paint job on those things is straight off of a 1980s disposable paper cup.

2017-08-08
2017-08-13
Harper Nalley
Harper Nalley9:15 AM

I would assume that one can paint them.

2017-08-17
Harper Nalley
Harper Nalley4:15 PM

2017-08-31
Harper Nalley
Harper Nalley9:21 PM

Will Hobbs
Will Hobbs9:41 PM

How has barn been going?

2017-09-01
Rose Bandrowski
Rose Bandrowski9:09 AM

Kenneth can better answer this question as I've been gone for the past few sessions due to college visits but last I saw the shooter was doing well and the design coming along. Apparently we have some 3D printed gear covers now for safety. We had the gearbox lock up due to lack of lubricant but that was fixed. The shooting accuracy seems to really depend on how the balls are fed in and I think that was tested some by putting some scrap wood on it to make a fixed feeding system however I wasn't there to see so I'm unsure how well that was working. Regardless, if you fed the balls on right they'd go quite far/high and was generally very successful.

Rose Bandrowski
Rose Bandrowski9:11 AM

I may be disillusioned but I think if we get a good feed-in system the shooter could do quite well as it's really only supposed to be an adjustment to the trajectory and speed of the ball.

Rose Bandrowski
Rose Bandrowski9:12 AM

Rather unsure at this point whether we will be able to finish it before girls generation though.

Will Hobbs
Will Hobbs11:12 AM

Thanks

Rose Bandrowski
Rose Bandrowski11:15 AM

Yup

2017-09-10
2017-09-14
Dana Batali
Dana Batali8:02 AM

better than legos! A 19th century guide to mechanical devices.

http://507movements.com

for example:
http://507movements.com/mm140.html

2017-09-17
Rose Bandrowski
Rose Bandrowski3:11 PM

I don't want to assume so I'm asking. We are not going to attempt finishing the shooter for Helios before girls generation, correct?

Rose Bandrowski
Rose Bandrowski3:11 PM

@Paul Vibrans

Kenneth Wiersema
Kenneth Wiersema3:13 PM

I thought the leadership team's general consensus was that we weren't going to finish it, as we would need far too much time to do so, that we don't have.

Rose Bandrowski
Rose Bandrowski3:13 PM

Okay I wanted to confirm, thank you.

Rose Bandrowski
Rose Bandrowski3:14 PM

Curious, will be want to finish after girls generation?

Rose Bandrowski
Rose Bandrowski3:14 PM

We didn't discuss that I don't believe

Kenneth Wiersema
Kenneth Wiersema3:15 PM

I would ask why, but we can, if we think it would be educational for the new people.

Rose Bandrowski
Rose Bandrowski3:15 PM

My thought exactly

Rose Bandrowski
Rose Bandrowski3:15 PM

Could be cool for showing off the robot (outreach), and good for teaching newbies.

Kenneth Wiersema
Kenneth Wiersema3:17 PM

I still think Atlas is the better show robot, but with ~4 meetings to do so, I doubt we could finish it.

Rose Bandrowski
Rose Bandrowski3:18 PM

True. We can consider it, lets discuss it at leadership next week

Kenneth Wiersema
Kenneth Wiersema3:19 PM

As an separate assembly maybe, but not mounting. Taking apart Ares would be easier

Rose Bandrowski
Rose Bandrowski3:19 PM

That would be interesting (for lack of a better word, sorry), but I think building is more valuable than disassembling.

Rose Bandrowski
Rose Bandrowski3:20 PM

Since in the long run that is what we need to be teaching them how to do.

Rose Bandrowski
Rose Bandrowski3:20 PM

I'm all in for murdering Ares regardless

Rose Bandrowski
Rose Bandrowski3:21 PM

Disassembling is intuitive and comes with the knowledge of assembling, but the opposite is not true.

Kenneth Wiersema
Kenneth Wiersema3:21 PM

True, but still we'll discuss it at the leadership meeting, and our track record for planning multi-meeting things is poor.

Rose Bandrowski
Rose Bandrowski3:21 PM

Agreed

Enrique Chee
Enrique Chee6:22 PM

We might also need the electronics from Aries.

2017-09-18
Paul Vibrans
Paul Vibrans9:43 AM

Would it help if the remaining complex parts for the new shooter were premanufactured?

2017-09-21
Bo Baird
Bo Baird7:16 AM

That Is AMAZING! that is such a cool resource! Thanks for sharing that!

2017-10-01
Chris Rininger
Chris Rininger9:57 AM

I was looking around for something that covered the major types of mechanisms I have not seen the past two years, and I found this on AndyMark. Some may have seen it before, but it seems worth sharing as an introductory reference. http://files.andymark.com/ManiupulatorDesign.pdf

2017-10-02
Paul Vibrans
Paul Vibrans10:33 AM

A good presentation overall but I disagree with his recommendation against scissor lifts. Their limitations have easy solutions.

2017-10-15
Darwin Clark
Darwin Clark4:07 PM

@Darwin Clark has joined the channel

2017-10-17
Mark Tarlton
Mark Tarlton7:17 PM

@Mark Tarlton has joined the channel

2017-10-25
Jules Blythe
Jules Blythe9:02 PM

@Jules Blythe has joined the channel

Micah C. Glasby
Micah C. Glasby9:51 PM

@Micah C. Glasby has joined the channel

Sean Williams
Sean Williams9:58 PM

@Sean Williams has joined the channel

Anna Banyas
Anna Banyas10:34 PM

@Anna Banyas has joined the channel

2017-10-26
Martin Vroom
Martin Vroom10:43 AM

@Martin Vroom has joined the channel

2017-10-28
Dana Batali
Dana Batali11:25 AM

lower rpm than I would have predicted.. Interested to hear others' thoughts on these specs:

2017-11-10
Paul Vibrans
Paul Vibrans9:01 AM

Much better efficiency than comparable brushed motors from the approved list and nice low speed operation but very bulky for the power or torque.

2017-11-13
Aiden Grayson
Aiden Grayson5:56 PM

@Aiden Grayson has joined the channel

2017-11-16
Chris Rininger
Chris Rininger8:43 AM

Sharing this thread for two reasons: 1) some intriguing new strong, lightweight construction products are introduced and 2) there is an interesting conversation about how a 6 miniCIM single speed has some major advantages over alternatives - this is an option that can readily be used with a kitbot & might be worth a look. https://www.chiefdelphi.com/forums/showthread.php?threadid=160093

2017-11-18
Enrique Chee
Enrique Chee7:26 PM

Mechanics, great team website for all engineering relate topics.http://www.team358.org/files/mechanical/

2017-11-20
Violet Advani
Violet Advani9:33 AM

@Violet Advani has joined the channel

2017-11-29
Brian McKinnon
Brian McKinnon6:35 PM

@Brian McKinnon has joined the channel

Tanner Nalley
Tanner Nalley7:18 PM

@Tanner Nalley has joined the channel

Kenneth Wiersema
Kenneth Wiersema8:51 PM

So basic resources for what was discussed tonight:

My slideshow: https://docs.google.com/presentation/d/1eJjTbcgL963iIE-crkDxifbasIihyMDhWBfanfzC8v4
Vex robotics motor page: http://motors.vex.com/introduction
Chief Delphi: https://www.chiefdelphi.com/forums/portal.php

I’ll be posting a more in-depth article over the weekend on the subject.

Kenneth Wiersema
Kenneth Wiersema8:51 PM

2017-11-30
David Ard
David Ard3:57 PM

@David Ard has joined the channel

2017-12-08
Harrison
Harrison4:36 PM

@Harrison has joined the channel

2017-12-10
Terry Shields
Terry Shields1:07 PM

Looking for help tomorrow after school - - on Monday Dec. 11 at 1:45pm - - Need 1 student to help me carry an FLL game table from Physics store room down to St. Cecilia School. This will only take 15 minutes.

James Sovick
James Sovick1:07 PM

I'll help you terry

Terry Shields
Terry Shields2:51 PM

Awesome James. We will meet in Mr. Chee’s room around 1:45 tomorrow. Thanks.

James Sovick
James Sovick3:17 PM

Ok!

2017-12-12
Nora Wilson
Nora Wilson9:00 PM

@Nora Wilson has joined the channel

2017-12-13
Chris Rininger
Chris Rininger12:47 AM

Seems like a quite relevant Behind the Lines episode coming up: when to use COTS vs custom designed/built items. https://www.chiefdelphi.com/forums/showthread.php?threadid=160463

2017-12-16
Chris Rininger
Chris Rininger8:01 AM

Good thread on pros/cons of including a belly pan in robot design. Electronics mounting / space efficiency / structural stability seem to be key strengths. https://www.chiefdelphi.com/forums/showthread.php?threadid=160489

2017-12-20
Kirsten Martel
Kirsten Martel1:05 PM

@Kirsten Martel has joined the channel

2017-12-21
Chris Rininger
Chris Rininger11:30 PM

Excellent new resource just shared: https://www.chiefdelphi.com/forums/showthread.php?threadid=160602

2017-12-22
Dana Batali
Dana Batali10:49 AM

Nice - I really like slides 35-36... We should consider using this table for prekickoff

2017-12-27
Chris Rininger
Chris Rininger8:00 PM

Very well done set of test data shared concerning 4 CIM vs. 6 CIM vs. 6 miniCIM vs. 6 775pro vs. 8 775pro drivetrains. It's a lot to look through, but I think the following statement from a recent post is a pretty good summary of applicable results: "4 CIMs have been good enough to run fully-weighted robots for a decade now, and they're still good enough moving forward. Teams who use different types or quantities of motors are optimizing for sprint time (8x775, 6xMiniCIM, or 6xCIM are better), weight (6x775 or 8x775 are better), or thermal buildup during finals (6 MiniCIMs are better)." Of course, with 6 CIMs or 8 775pros, special measures must be taken to avoid brown out failures. Also, the tests were all done with a 2-speed transmission (though it is COTS). On the topic of 2-speeds, if the programming team ends up adopting some/all of 254's drivetrain code, then I suspect there is auto-shifting software in there that could be used if the team is interested in trying a 2-speed now or in the future.

Here's the thread with the paper / test results: https://www.chiefdelphi.com/forums/showthread.php?t=160387

Declan Freeman-Gleason
Declan Freeman-Gleason8:24 PM

@Chris Rininger You're correct that 254's codebase includes auto-shifting, but it's not exactly a plug-n-play type of thing to get working, so we should carefully evaluate the benefits of such a system before we commit to it.

Terry Shields
Terry Shields9:01 PM

I agree. These tables are simple but can covey a lot of information. Especially if all our sub teams use the same format.

One last note to the engineering team. The above link that Chris found has a lot of slides (and I mean a lot!) but it is packed with good information and good engineering practices throughout. Also, take a look at some of the close-up photos of their previous robots - their mechanical construction is beautiful.

2018-01-06
2018-01-07
Riyadth Al-Kazily
Riyadth Al-Kazily10:35 AM

Here is a great overview of "hobby" servos to give some background on their capabilities. I recommend watching this to see where we can apply them in our mechanisms. They are small, inexpensive, and can be very precise -- just right for fine, detailed motion control applications. https://youtu.be/iH9xtulyws

Enrique Chee
Enrique Chee11:31 AM

Thanks Riyadth and Katie. Katie, I have ordered 10 Game piece cover.

Harper Nalley
Harper Nalley8:38 PM

When we get to engineering modules, we might be able to look at this year’s FTC robots because they also had to lift cubes.

Chris Rininger
Chris Rininger8:57 PM

I think our standard is 6-inch wheels, so we're probably fine... but, depending on wheel size & how wheels are configured with chassis, folks have pointed out the risk of beaching / high centering on the climbing ramp corners. Since chassis work is coming up, seems good to share: https://www.chiefdelphi.com/forums/showthread.php?threadid=161090

Dana Batali
Dana Batali9:05 PM

https://www.youtube.com/watch?v=m75h9VW4S2s&feature=youtu.be&t=207

Shows many interesting grabbers and a very unique interpretation of the climber rule where a helper elevates two teammates

Apologies for the headbanger backing track

2018-01-08
Paul Vibrans
Paul Vibrans2:54 PM

High centering on ramps is not a function of wheel diameter, just wheel spacing and ground clearance. Ground clearance is 2" maximum from Rule R24 and Figure 8-6. It could be less with sloppy construction.

Chris Rininger
Chris Rininger6:09 PM

@Ethan Rininger: best “climb on me” ramp from 2007 evidently: https://www.chiefdelphi.com/forums/showthread.php?threadid=161021

Dana Batali
Dana Batali6:53 PM

2:58 in above youtube

Dana Batali
Dana Batali6:53 PM

ideally ours might be less bulky

Grant
Grant7:45 PM

@Grant has joined the channel

2018-01-09
Chris Rininger
Chris Rininger1:40 PM

See post 7 if we end up looking at a COTS elevator component: https://www.chiefdelphi.com/forums/showthread.php?threadid=161189

Enrique Chee
Enrique Chee2:08 PM

We have about 3 COTS system already.

Cruz Strom
Cruz Strom5:25 PM

Chris Rininger
Chris Rininger11:20 PM

Not sure whether to put this in engineering or programming. This CD thread is talking about how to maximize elevator speed via controls tech. The 4th post mentions using a PID on Talons, which I believe we already use (with drivetrain?), but also Motion Magic and Motion Profiling. Anyway, given elevator direction is likely, maximizing lift speed while sustaining control seems like a timely topic. https://www.chiefdelphi.com/forums/showthread.php?threadid=161185

2018-01-10
Kenneth Wiersema
Kenneth Wiersema7:35 PM

Something to keep in mind https://frc-qa.firstinspires.org/qa/1

Rose Bandrowski
Rose Bandrowski7:57 PM

ultimate POWER!

Rose Bandrowski
Rose Bandrowski7:57 PM

(but that's good to know)

2018-01-11
Kenneth Wiersema
Kenneth Wiersema1:16 PM

Another thing to keep in mind https://frc-qa.firstinspires.org/qa/82

John Sachs
John Sachs10:52 PM

If the team does decide to proceed with placing cubes accurately, we will need some lateral capability to do fine adjustments quickly. Given mecanum wheels seem to be a no go, another approach could be to replicate a capability that many forklifts have, called a sideshifter, which allows the operator to move the tines or arms laterally for easier and quicker placement of the load without repositioning the forklift.

John Sachs
John Sachs10:55 PM

Lots of other real-world forklift attachments at this site to give you some other ideas for end-effectors (l like the layer picker): www.cascorp.com/Americas/en/home

2018-01-12
Dana Batali
Dana Batali9:08 AM

interesting - seems to suggest a powerless version of the park+double-"climb". Specifically if going up the ramp causes bumpers to exceed the 12 in limit, then no lifting would be required.

Harper Nalley
Harper Nalley9:14 AM

I think would also be relatively easy to integrate into any design.

Riyadth Al-Kazily
Riyadth Al-Kazily4:33 PM

I have seen some interesting mechanisms recently (not much on FRC bots) that use ball bearing drawer slides for linear guides. It seems that we could use some of those to mount our mechanism to the robot base and get reliable side-to-side motion capability.

Riyadth Al-Kazily
Riyadth Al-Kazily4:36 PM

Here is a video of a guy making modifications to drawer slides for use on a home made milling machine: https://youtu.be/mPkwIG7og44

Tanner Nalley
Tanner Nalley10:26 PM

Tanner Nalley
Tanner Nalley10:26 PM

Tanner Nalley
Tanner Nalley10:26 PM

Kenneth Wiersema
Kenneth Wiersema10:40 PM

If anyone is curious on why scissor lifts are not more common, or why the experienced students are hesitant of them https://www.chiefdelphi.com/forums/showthread.php?t=132364&page=2&highlight=Scissor+lift

2018-01-13
Enrique Chee
Enrique Chee12:39 AM

We have this lift system that was used for Gaia. https://www.competitionrobotparts.com/designs/

Enrique Chee
Enrique Chee12:56 AM

We can also take this system,http://www.andymark.com/product-p/am-3844.htm and design it like the GAIA system above.

Enrique Chee
Enrique Chee2:05 AM

Maybe we should remove the intake from ARIES to prototpye our intake on Sun. Someone please get Aries off the shelf.

Randy Groves
Randy Groves10:07 AM

@Randy Groves has joined the channel

Chris Rininger
Chris Rininger10:20 AM

I was just about to post that one. I am finding examples of successfully used high-reaching scissor lifts. I think the warnings may be in the context of teams running into problems by not designing/manufacturing carefully enough. I actually think if the compactness of a scissor lift (when down) would allow other things to be built (shooter on top) without top heaviness when running around on the field, then it could be pretty cool.

Another scissor lift from the past:
https://www.youtube.com/watch?v=FWHihn28gxA

And check out these monstrosities from 2000 - one of them is a scissor lift, but there are other designs as well. If pictures from 2000 can be found, it might be a good year to look at closer for ideas: https://www.youtube.com/watch?v=YCcBXMrR8DY

Chris Rininger
Chris Rininger10:30 AM

Scissor climber from 2016: https://youtu.be/3ukMPN73LB0?t=146

Chris Rininger
Chris Rininger10:38 AM

SnowProblem's day 1 prototyping is interesting - they compare elevator and scissor lift (& they ended up with shooter, right?): https://www.youtube.com/watch?v=fwJRZdVmfHM

Paul Vibrans
Paul Vibrans11:23 AM

Snow Problem's scissors lift prototype is too crude to use as an example for value judgements. Our prototype is made of suitably sized pieces of wood, not 2x4's.

Bill Bandrowski
Bill Bandrowski11:28 AM

I believe Grant's design has merit and deserve's more attention. Below is his original drawing. The link below is to an FRC robot that used a similar design/system. Grant's counter balance design could accelerate the arm up even more rapidly with little motor force. An elevator system could work in place of the telescoping arm. I think it is worth prototyping.

Bill Bandrowski
Bill Bandrowski11:30 AM

Here is the link to an FRC robot that uses a similar design: https://www.youtube.com/watch?v=SZ7jTKJNLzg

Paul Vibrans
Paul Vibrans11:36 AM

Why prototype it. Clearly it can work. The time spent prototyping would be done better working out the details if that is the mechanism the team wants to use.

Chris Rininger
Chris Rininger11:50 AM

I wasn't using the video to knock on the scissor lift option; I just thought it was a good walkthrough of lots of different prototype options with good dialog. One of the students even made a statement similar to yours about elevator lifts ("we know elevators work - we don't need to prototype one"...)

Harper Nalley
Harper Nalley11:55 AM

This is the ramp bot Harrison and I looked at from 2007.

Bill Bandrowski
Bill Bandrowski12:04 PM

Interesting ramp idea - but it looks like they had to sacrifice all other mechanisms (from what I could see in the video, not sure).

Bill Bandrowski
Bill Bandrowski12:09 PM

Regarding the Monkey Wrenches' robot design above, it looks like they were successful that year: "Robotics Team 2016 was very successful at both their regional competitions in Trenton and Washington, DC. They were awarded the prestigious New Jersey Regional Chairman’s Award as well as the Judges Award in Washington, D.C. ...their great accomplishments have launched them to the International Championships, which will be held in St. Louis, April 2011."

Bill Bandrowski
Bill Bandrowski12:19 PM

Mighty Monkey Wrenches 8th match on Archimedes in St. Louis: https://youtu.be/X0An5xCH0hU

Bill Bandrowski
Bill Bandrowski1:55 PM

The above video also provides a look at vertical elevators and how they compare in competition.

Dana Batali
Dana Batali2:18 PM

https://www.twitch.tv/videos/216920302 (see around 7:06:15 - 2 ramp plus intake). Still haven't found fully functional reveal video.

Harper Nalley
Harper Nalley3:06 PM

Yeah. I think having a ramp could make us very useful at lower competitions ESPECIALLY if we can then get 3 climbs without using levitate. If this were last year, i wouldn’t say lifting 360lbs was a feasible option, but this year there is no limit on the number of CIMs we can use.

Chris Rininger
Chris Rininger3:55 PM

If we're talking ramps it might be good to look at mobility ramps to get ideas since wheelchairs have a roughly similar size, weight, and center of gravity to robots, and the height to climb up to a van or porch are also roughly similar to our climbing task. The middle hinging ones seem interesting from a pre-endgame space perspective. https://www.discountramps.com/wheelchair-ramps/c/3100/pgsize/All/

Riyadth Al-Kazily
Riyadth Al-Kazily4:30 PM

Just saw this video of a triple-climber: https://youtu.be/Psj4JItCh4c

Riyadth Al-Kazily
Riyadth Al-Kazily4:34 PM

This follow-up may be important: https://youtu.be/-CwEBfPGTPw

Paul Vibrans
Paul Vibrans5:02 PM

Way less complicated than the side ramps I was thinking of. An idea worth stealing. I would fill in the rectangular space with polycarbonate or something like it for carrying sponsors' names and for deflecting cubes thrown up by low shooter bots.

Darwin Clark
Darwin Clark5:04 PM

It seems like their climbing system took very minimal space on their robot. Is it reasonable to assume that there is enough room for a cubes manipulator on the rest of the bot?

Harrison
Harrison5:05 PM

Maybe

Harrison
Harrison5:06 PM

The only problem is that the rope is going at a diagonal being in the way of the cube lifter

Harrison
Harrison5:06 PM

So if we were we would need to make a small compact lifter

Riyadth Al-Kazily
Riyadth Al-Kazily5:12 PM

The second video shows a space that they think might hold a cube handling system. But they only worked on the climber, and didn't design the robot to manipulate cubes.

Harper Nalley
Harper Nalley7:03 PM

I think we should take that idea (ground level plates) rather than taking the whole mechanism. I think this does prove that this system can lift 3 robots though which is (in my opinion) very important. Why? Because it means we don’t HAVE to waste 3 cubes on Levitate so we (or our alliance) can put those on switches and on the scale, or devote them to other power ups.

Harrison
Harrison7:04 PM

That is true

Harrison
Harrison7:05 PM

Plus possible alliance if we don't make it to playoffs

Harper Nalley
Harper Nalley7:21 PM

Yeah. Furthermore, there is no longer a limit on the number of CIM motors, so we could use a dual CIM climber, meaning we won’t be nearly as slow as we were last year (potentially).

2018-01-14
Charlotte Larson Freeman
Charlotte Larson Freeman3:47 PM

Harper Nalley
Harper Nalley4:51 PM

Skip to 5:50

Enrique Chee
Enrique Chee7:48 PM

Thanks Chris !!

Will Hobbs
Will Hobbs8:51 PM

Does anyone have a picture of the prototype scissor arm?

Harrison
Harrison8:52 PM

I may

Will Hobbs
Will Hobbs8:53 PM

If you do please send it

Harrison
Harrison8:53 PM

Is this good

2018-01-15
Chris Rininger
Chris Rininger8:37 AM

118 released their "everybot" - a fast cycling exchange/switch placing bot. Check out how the intake can take cubes in any orientation. https://www.youtube.com/watch?v=RQNCeHsOeJE&feature=youtu.be

Chris Rininger
Chris Rininger8:46 AM

Updated intake examples PDF - now includes Robonauts' "Everybot" intake, which can intake cubes in any orientation

Justice James
Justice James10:27 AM

@Justice James has joined the channel

Andrew Peterson
Andrew Peterson11:03 AM

Here is the list of steps and requirements for the climber. Feel free to add comments.
https://docs.google.com/spreadsheets/d/16UsQbuSxHZaBjMxUQS0OeBaFg87fXKBlKat4cA1Hs

Kenneth Wiersema
Kenneth Wiersema4:26 PM

I added three new channels for each of the modules in slack today. All mechanics should join the channel of the sub team team that they are on, and I would strongly recommend joining the other ones for communication purposes.

Kenneth Wiersema
Kenneth Wiersema4:26 PM

Will Hobbs
Will Hobbs8:56 PM

FYI I have put together the basics of the scissor lift and attached it to a chassis in CAD

Will Hobbs
Will Hobbs8:56 PM

It is under the scissor lift tab\

Bill Bandrowski
Bill Bandrowski9:45 PM

Is that in the cad file system?

Will Hobbs
Will Hobbs9:45 PM

Yes

Will Hobbs
Will Hobbs9:45 PM

I can send a screenshot if you want

2018-01-16
Kenneth Wiersema
Kenneth Wiersema7:00 PM

Currently what the space allocations look like.
8” x 27.5” for scissor (blue)
20.5” (really the entire front of the robot right now) x 4.5” (red)
2 (6”x12.5”) space for Climbing ? I still don’t get the set up right now. (interior grey boxes)

Battery goes in the back of the robot next to the scissor. (up being front in the image)
There looks like a possible interference with the climbing, but the space is supposed to be mostly empty space?

As well, I would like Dimensioned Drawings for each of the modules by the end of the meeting, and the beginnings of a CAD file. (The CAD file is to be completed by the beginning of the meeting on Friday ideally).

At the very least, show me what you’re talking about in a large, detailed drawing, so I can start sorting issues out tomorrow, rather than when the CAD’s are done.

2018-01-17
Chris Rininger
Chris Rininger7:34 AM

Kenneth, I have an ask: Could we get two perspective views (maybe looking down from back left and looking down from front right) instead of just the top down? Reason: systems will probably need to share space from a top-down perspective. For example, the climbing winch may need to be above the intake - looking at what you have so far, it seems likely.

Kenneth Wiersema
Kenneth Wiersema7:43 AM

I haven’t really done height allocations, mostly due to the robot starting height can be 55in, and I was having a hard time placing the climbing volume, due to them being directly intergraded with the scissor lift. As well, this is the first I think I heard of the winch being located above the intake, as what I heard at the meeting it was going to be under the scissor lift.

That’s why I was also waiting for the drawings of the modules, so I can start seeing how everything is going to fit together, as the scissor lift was the only thing I have a semi-understanding of how it is going to go together and placed on the robot.

Anna Banyas
Anna Banyas8:28 PM

@Anna Banyas has left the channel

2018-01-20
Binnur Alkazily
Binnur Alkazily11:23 AM

@Kenneth Wiersema gentle reminder to keep camera in mind. we have 4 years of experience that tells me it can’t be an after thought that we can decide the bag day. thanks!

Kenneth Wiersema
Kenneth Wiersema11:27 AM

I currently have no idea where I can even put it, as if it needs to as close to the center of the robot as possible, but still not getting in the way of the intake, which I haven’t seen a solid design for yet, and it’s not in cad yet. And it can’t go on the scissor lift so, there are not a lot of places left. I need Intake designs before placing it.

Chris Rininger
Chris Rininger11:58 AM

How will driver/operator aim where to place cube on scale without a camera on the lift? I was assuming a cable would be run up to a camera on the lift for the purpose of aiming. Let's discuss.

Chris Rininger
Chris Rininger11:59 AM

Unless we have a separate way to mount a camera high

Kenneth Wiersema
Kenneth Wiersema12:00 PM

This to my understand was for vision not for driver use. The camera that you are discussing would be for driver use only, but I got confirmation from Darwin that they don’t want it on the scissor lift.

Chris Rininger
Chris Rininger12:02 PM

ah, ok, makes sense - please do plan on a camera on the lift though. Without it, I don't see how we'll achieve precision that would be better than a low shooter.

Chris Rininger
Chris Rininger11:15 PM

Following up: I played around in Synthesis & from that I do believe having a high camera view will be super helpful - we will perform better at placing if we have one IMO. Here's a picture: https://1drv.ms/i/s!AkoZXdKPoojXjqN6UuFUPzRoafjQ

Chris Rininger
Chris Rininger11:16 PM

I think locating it all the way at the back of the lift, somewhat higher than the top of the lift, will be the way to go.

Chris Rininger
Chris Rininger11:18 PM

I remember last year there was a way to look at the latest working version of the full robot in Fusion 360 - is that possible this year? The climbing design will be constrained by the lift & intake, so good for us to be able to always look at the latest. thanks

Chris Rininger
Chris Rininger11:25 PM

Full inspection video: https://www.youtube.com/watch?v=W-biy-NLmWQ

2018-01-21
Will Hobbs
Will Hobbs10:03 AM

Kenneth or I can show you where to find the most recent file on fusion at today’s meeting

Paul Vibrans
Paul Vibrans10:52 AM

We can mount the camera on the scissor lift. Creativity is required.

Chris Rininger
Chris Rininger10:59 AM

From working in the simulator, the higher the better. If the top of the scissor lift platform is 40 inches at the start of the match, for example, it'd be good to have the camera at the back behind everything, as close to the 55 inches as we're comfortable. I'm not sure if you saw the screen shot from the simulator - here it is: https://1drv.ms/i/s!AkoZXdKPoojXjqN6UuFUPzRoafjQ

Enrique Chee
Enrique Chee11:14 AM

@Chris Rininger it is under a folder call Spartronics and then a folder called Power Up

Enrique Chee
Enrique Chee11:15 AM

In fusion 360

Will Hobbs
Will Hobbs8:59 PM

This is a link to our inventory sheet for reference.
https://docs.google.com/spreadsheets/d/1bmWkvP3pyDZnIK-7-0UKK7PyeKFqyp173MM4soqi8

Will Hobbs
Will Hobbs9:00 PM

@Will Hobbs pinned a message to this channel.

Enrique Chee
Enrique Chee9:01 PM

Please make sure @Kaedric Holt and @Jack Chapman and @Peter Hall is updating. Thanks

2018-01-22
Chris Rininger
Chris Rininger1:19 PM

Idea concerning the climb with friends dropdown forks... in the rules figure 8-2 indicates chassis sides are not required to be covered by bumpers... only the corners are required. I could see it being advantageous to leave our robot sides uncovered so the forklift platform could wrap tight around the chassis when they are in the lowered position. In fact, a robot shared by Bill B on the climbing channel is set up just like that. Thoughts?

Chris Rininger
Chris Rininger1:56 PM

Chris Rininger
Chris Rininger1:57 PM

now that I look at the picture, the things on the corners are pretty clever as well for being able to track the robot when other robots or field pieces are obscuring it

Binnur Alkazily
Binnur Alkazily5:47 PM

we added something like that to our robot 2 years ago after the 1st day of the competition. Through experience, we also learned about bendy pieces extending beyond the frame perimeter

2018-01-23
Chris Rininger
Chris Rininger7:00 AM

Lucas, I'd like to not just dismiss having openings in the bumpers because there are advantages to consider in addition to the disadvantages of the bumper mounting being different. Here's a picture to illustrate the advantages.

Harrison
Harrison1:16 PM

I talked about this to Lucas and, it is a good idea but those kind of bumpers fall off the robot very easily.

Harrison
Harrison1:17 PM

Most teams do that because they are easy to build but they are easy to fall off

Enrique Chee
Enrique Chee4:45 PM

FYI. We have constant force springs. Maybe we can use for intake. These springs are similiar to a tape measure that rewinds itself.

Enrique Chee
Enrique Chee4:48 PM

We have some from previous years. We can get 6 more free ones. Please let me know and I will order them. @Chris Rininger @Paul Vibrans @Mark Tarlton @brian_bonifaci

Chris Rininger
Chris Rininger6:17 PM

@Harrison: @Harper Nalley It appears Team 16 did the corner bumpers last year... https://m.imgur.com/YUkFvkb

Dana Batali
Dana Batali6:25 PM

good thing they only have 2 digits in their team number :slightlysmilingface:

2018-01-24
Harper Nalley
Harper Nalley12:18 AM

@Chris Rininger Corner bumpers would require us to completely rebuild the mounting hardware. Essentially we’d be starting from scratch. Also, I’ve seen several teams use them, and they simply don’t work.

Chris Rininger
Chris Rininger6:58 AM

@Harper Nalley: I hear that it would require an updated approach & it would be a challenge, but I question the “simply won’t work” assertion. If the “climb with friends” platforms/forks will be more stable, simpler, and possible lighter if butted against the chassis rather than against bumpers, then does it make sense to prioritize avoiding a bumper design challenge over that? I did some research myself last night indicating corner bumpers can be done in a way that they work and don’t fall off. Let’s discuss live next meeting.

Paul Vibrans
Paul Vibrans8:11 AM

Have the bumper attachment points on the chassis been located yet or have any of them been installed? They should be shown on the CAD model if and when they are.

Paul Vibrans
Paul Vibrans8:13 AM

Does the plywood backing on the bumpers have pockets to clear the bolt heads that project from the chassis?

Paul Vibrans
Paul Vibrans8:14 AM

Put another way, does the plywood fit tight to the aluminum sides?

Will Hobbs
Will Hobbs11:15 AM

The plywood will sit flush to the chassis

Will Hobbs
Will Hobbs11:16 AM

And the locations for the brackets are taped onto our chassis but I don’t know if it is in cad yet

Harper Nalley
Harper Nalley2:15 PM

@Chris Rininger the reason I said that was based off of watching other robots use them.

Enrique Chee
Enrique Chee2:29 PM

@Harper Nalley I suggest we stop construction on the bumpers until we finalize the different mechanisms.

Harper Nalley
Harper Nalley2:29 PM

I agree

Mark Tarlton
Mark Tarlton7:06 PM

I'd like to see what we have. They could be used with the arm that connects the grabber to the lift to help counterbalance the weight of the cube. They should be in the relaxed position when the arm is laying back on top of the lift and then under tension when reaching forward and down.

Cruz Strom
Cruz Strom7:20 PM

Here is how the Scissor Lift works: According to Paul: Two air cylinders working in parallel raise the lift. Air is admitted to the cap ends while the rod ends are open to the atmosphere with no tube connections at all. Two solenoid valves are required; they should not be the spring offset type.

Valve 1 has the pressure input connected to the tank and the A output connected to both cylinder cap ends and the B output plugged. Sending air to the A output raises the scissors and sends air to Valve 2. Sending air to the B output does nothing.

Valve 2 has the pressure input tapped into the tube(s) between the cylinder cap ends and the A output of Valve 1. The A output of Valve 2 is blocked and the B output vents to atmosphere.

To raise the scissor, shift both valves to the A position. To hold the scissor in the up position, shift Valve 1 to B and Valve 2 to A. To drop the scissor, shift both valves to the B position.

A third, small, spring retract air cylinder actuates a toggle on one of lift cylinder rods to stop the scissor at any height. It will not stop the scissor from collapsing. One solenoid valve is required to admit air to the cap end.

Valve 3 has the pressure input connected to the tank and the A output connected to the small cylinder cap end. The B output of Valve 3 is blocked. To stop the scissor at a particular height, shift Valve 3 to A. The toggle will not release to let the scissor rise higher until Valve 3 is shifted to B and the scissor is allowed to drop slightly.

Position indication for the scissor is by a single turn potentiometer mounted at mid-height on the scissor and connected between one outer link and the shaft that is rigidly attached to the inner link.
The range of rotation is 123 degrees.

The cylinders have magnetic pistons that can activate switches, if installed on the outside of the cylinder body, that can be used to send a signal to the RoboRio to operate solenoid valves. The switches mount with a band around the cylinder at whatever position where something is supposed to happen. More than one switch can be mounted on a cylinder as long as they do not interfere physically. With two cylinders working together, a switch that otherwise can’t be mounted because another switch is in the way can be mounted on the second cylinder. At this time there is no plan to use these switches. One thing to consider is that trying to stop the cylinder just by closing the air valve may not be successful because the air may continue to expand in the cylinder after the valve is closed, pushing the cylinder farther. This is the case when a Power Cube is released and the weight supported by the scissor is reduced; the scissor will go up. A possible use of these switches would be to shut off the air before the scissors reach full height but with still enough pressure to carry the scissors to their maximum elevation; this will save air.

Binnur Alkazily
Binnur Alkazily9:21 PM

@Binnur Alkazily pinned a message to this channel.

Binnur Alkazily
Binnur Alkazily9:22 PM

WOW! Nice set of details, thank you @Cruz Strom The message is pinned to the channel, and lets keep any discussion on scissor lift design to this thread.

2018-01-25
Declan Freeman-Gleason
Declan Freeman-Gleason1:37 PM

This is a great model for what the other subsystems need to post!

Dana Batali
Dana Batali2:59 PM

a picture would be worth 1000 words for my brain

Rose Bandrowski
Rose Bandrowski5:38 PM

Harvester:
The first thing the cube interacts with with the robot is going to be the harvester. The purpose is so that it allows for our grabber to be more accurate when grabbing the cube and reduces alignment time for the driver.

At the beginning of a match, the two arms will be folded in (I wanted to dub it the origami mechanism because it folds… hah) so they fit within the frame perimeter. We’re using a 7 inch pneumatic piston to do this. I’m forgetting on how it’s attached, I will update this eventually and if it’s important, ask me at the meeting tomorrow.

Note:
Piston Open - arms close
Piston Retract - arms open

For auto, we’re likely going to want a sensor to able to align with/detect a cube (if we’re doing a two cube auto, that is). We thought limit switches might work for this, but some sort of distance detector would be better.

To physically interact with the cube, we have pulleys on each arm of the harvester which will be individually run by bag motors with 10:1 gearboxes.

The cube will be pulled in close to the frame and will theoretically set off a sensor that will either (unsure on which is better): automatically have the grabber come grab it if the sensor says it’s well aligned or will let the driver/mechanism controller know the cube is aligned so they can tell the grabber to get the cube. Undecided, depends on what the driver/mechanism controller want.

Once the cube is aligned, the arms will open and the grabber will grab onto the cube. Timing is going to be interesting here. Especially since we’re going to likely be moving with the cube in the harvester and a quick handling of the cube to the grabber from the harvester may be strategically important. Tweaking involved.

It’ll be important to be able to open up the arms and be able to close them because if we’re being defended against we’re going to want to apply pressure (open piston) to be able to hold onto the cube better, or if we’re moving. It’s a method to be able to hold the cube better.
Then, if we have no cube in the harvester, and we want to get a cube off a second stack, we can’t control the bottom cube because that would result in a foul so the harvester needs to close - fast. Driver is going to have to do more work to align with the cube that’s on the second level of the cube stack.

Grabber:

Piston Open - arms open
Piston Retract - arms close

Grabber will be rotating up and down from the scissor lift from a winch system (?) that Paul devised. It’s powered by a CIM. Cruz should have more details than me.

It’s powered by a 10 inch pneumatic and is designed to grab the cube the same way time the same way. It should be grabber onto the handles of the box if in the short position, but pneumatics are strong and the grabber arms will also be able to grip if it’s in the tall position. We tested this.

Grabber will lift the cube up to its highest point and open the pneumatic to release the cube. Because of how the grabber is designed with the backplate, the cube will slide off the backplate if fully lifted.

There’s not a lot of sensor consideration here, but perhaps a pressure sensor to make sure the cube is well grabbed. Can be discussed further.

Rose Bandrowski
Rose Bandrowski5:39 PM

This should be a good summary - I can further explain details if they're unclear or need explanation.

Rose Bandrowski
Rose Bandrowski5:39 PM

@Rose Bandrowski pinned a message to this channel.

Jack Chapman
Jack Chapman7:06 PM

How climber will work:
1. Scissor lift will extend and grabber arm on the scissor will swing until hooks latch onto ring
2. Forward stabilizers (driven by 2 pneumatic pistons) will extend, either simultaneously or one staggered after another
4.climbing motors will engage (2 CIMs 1:64 gearbox ) until robot has reached sufficient height (approximately 50 in spooled in

2018-01-26
Mike Rosen
Mike Rosen4:33 PM

What Dana said. +1. I'm a visual learner.

Josh Goguen
Josh Goguen5:12 PM

@Josh Goguen has joined the channel

Michelle Dalton
Michelle Dalton5:17 PM

@Michelle Dalton has joined the channel

Kenneth Wiersema
Kenneth Wiersema7:32 PM

Mounting could possibly change still, so things can change to accommodated additional mechanisms.

Chris Rininger
Chris Rininger9:52 PM

Quick question: Is there a constraint that absolutely blocks us from climbing with the hook on the back / opposite side of the lift from the grabber? I ask because there's nothing on that side of the robot and a lot of stuff on the "front". How high can the the circled spot go with the fully extended?

Binnur Alkazily
Binnur Alkazily10:01 PM

@Binnur Alkazily pinned a message to this channel.

Will Hobbs
Will Hobbs10:31 PM

I think you can mount there but it will be much closer to the front of the robot when fully extended

Chris Rininger
Chris Rininger10:42 PM

Right... Probably more than 8 1/4" away from the bumper edge?

2018-01-27
Will Hobbs
Will Hobbs6:31 AM

There should be a cad with the scissor funny extended where you could look

Paul Vibrans
Paul Vibrans8:22 PM

The pivot point where the flipper attaches to the top of the scissor is 9.3 inches back from the bumper line and 0.8 inches above the top of the rung when the scissor is extended to full height. The corresponding end of the scissor that you are considering for attaching the hook is 22.2 inches back from the rear bumper line and 2.5 inches below the top of the rung when the scissor is extended to full height. We can put a hook or hooks where you would like if we put them on a second flipper so the hook(s) do not hang over the back of the robot when the scissor is all of the way down. This means adding a second flipper with some kind of drive. This would put the crosshead guides on the end opposite from the gatherer, which is good. Getting the geometry to remain satisfactory as the scissor collapses during the climb is key.

Chris Rininger
Chris Rininger10:36 PM

Thanks @Paul Vibrans. My motive of considering the back for climbing was simplification (it's out of the way) & minimizing risk to the highly important grabber. What you described seems like it would add considerable complication to the scissor lift, and as far as geometry the back is a worse spot for the hook to catch the rung as well. Partway up the flipper arm (i.e. existing plan) seems like it will be a nearly perfect place for the hook given the measurements you shared. Best risk mitigation is likely to not place the hook any further up the flipper arm than necessary so there is a bit of a space buffer. So let's stay the course with the hook on the existing arm unless others would like discuss further.

2018-01-28
Paul Vibrans
Paul Vibrans7:12 AM

We need to put the grabber in the 3-D model to make a final judgement

Kenneth Wiersema
Kenneth Wiersema10:21 AM

Here's the scissor lift more or less extended. The climbing hooks cannot be placed on the back of the scissor lift, so I agree that they should be kept where they are, (under the grabber) however there needs to be some talking with the grabber group to sort out the placement of the hooks, and to potentially make the grabber arms longer

Ted Larson Freeman
Ted Larson Freeman1:42 PM

@Ted Larson Freeman has joined the channel

Riyadth Al-Kazily
Riyadth Al-Kazily2:34 PM

Cory_Houser
Cory_Houser4:54 PM

@Cory_Houser has joined the channel

Binnur Alkazily
Binnur Alkazily7:28 PM

@Binnur Alkazily pinned a message to this channel.

2018-02-02
Mark Tarlton
Mark Tarlton6:40 PM

I did some testing of the x-carve using a 1/4" carbide endmill. The results are very encouraging. I'll post the details later, but the attached video shows 1" holes being cut in thick walled aluminum.

Enrique Chee
Enrique Chee6:48 PM

Great !!! Thanks !

Will Hobbs
Will Hobbs7:19 PM

That looks really good

Will Hobbs
Will Hobbs7:19 PM

Thank you

Paul Vibrans
Paul Vibrans8:09 PM

That is truly exciting!! Great work.

Mark Tarlton
Mark Tarlton8:46 PM

It sliced through sheet stock easily as well. It was less than a minute to cut a simple bracket with a single bearing hole. The other surprise was it wasn't very noisy when it was cutting properly. The next step will be to have fusion 360 generate the g code. This test was done using Easel only. Drilling small holes is still pretty painful. The small mills we have don't cut nearly so well. With recommended speeds and feeds it's 5 minutes per hole for 3/16" dia. I think we should try using short drill bits instead if we can find ones that fit the chuck on the router.

Kenneth Wiersema
Kenneth Wiersema9:36 PM

I'd want to do some research on that, as if the cnc tries to cut how it typically would, we would be breaking a drill bit.

Mark Tarlton
Mark Tarlton9:51 PM

Right, that's why I want to use Fusion for g code generation. It offers drilling as an explicit type of cnc operation. It can generate paths that are exclusively plunge cuts with no lateral movements. You specify drill bit and diameter as the cutter.

Kenneth Wiersema
Kenneth Wiersema9:52 PM

Okay, I haven’t looked much into the Fusion cnc interface, but if we can do we should try it.

Will Hobbs
Will Hobbs9:55 PM

You can also use the v carve program to generate g code

Mark Tarlton
Mark Tarlton10:02 PM

Yeah, I looked at it this afternoon. The first problem I ran into is the file export/import hassles. It would be nice if we could stay in fusion all the way to gcode generation. Fusion seems to support a lot of milling techniques but the user is responsible for figuring out how to go about making the part. My gut feel is that it's with the effort to figure it out.

Kenneth Wiersema
Kenneth Wiersema10:04 PM

Okay, I think we might want to table this til a little later in the season when there’s not as much work to be done, depending on when we get the robot done. But I’d like to keep this in mind for next year

Kenneth Wiersema
Kenneth Wiersema10:23 PM

Here’s the inspection checklist for this year, please take some time to look it over https://firstfrc.blob.core.windows.net/frc2018/Manual/2018FRCInspectionChecklist.pdf

Will Hobbs
Will Hobbs10:27 PM

Thanks Kenneth

Riyadth Al-Kazily
Riyadth Al-Kazily10:59 PM

Kenneth is asking nicely, but really everyone who is contributing to the build of this robot should read the inspection checklist, and get some attention on any issues that may result in inspection problems. If you're working on a subsystem, find the checklist items that address your design, and if you think there might be an issue then tell your team lead or a mentor. Let's try to pass inspection on the first try!

Enrique Chee
Enrique Chee11:49 PM

Thanks ! @Riyadth Al-Kazily for the great suggestion .

Chris Rininger
Chris Rininger11:57 PM

Back on 1/20 I shared a full inspection video done by a robot inspector on one of the RI3D bots, in case that is helpful

2018-02-03
Jim Carr
Jim Carr11:26 AM

Thanks Mark for the effort on the Carver, that’s what we had in mind to begin with for capabilities. The climbing team could carve a hook if the CAD file is complete.

Ronan Bennett
Ronan Bennett2:05 PM

@Ronan Bennett has joined the channel

Sean Lafer
Sean Lafer3:06 PM

@Sean Lafer has joined the channel

2018-02-05
Binnur Alkazily
Binnur Alkazily3:33 PM

@Ronan Bennett @Noah Martin ^^^ pls review from programming perspective

Ronan Bennett
Ronan Bennett3:45 PM

@Binnur Alkazily the only programming considerations I found were making sure the roborio and driver station are up to date, and the team number is in the driver station correctly.

Binnur Alkazily
Binnur Alkazily3:47 PM

Yup - that pretty much covers it. for our internal checklist, we also want to make sure we validate the latest versions of the fw as well. thanks

2018-02-11
Dana Batali
Dana Batali2:05 PM

@Kenneth Wiersema: i see there are longer picam cables in lengths 100 and 200 cm... Preference?

Kenneth Wiersema
Kenneth Wiersema2:06 PM

100 cm is more than enough, I don't need 2 m of cable, something shorter would be nice too, maybe triple the current cable length would be best

Dana Batali
Dana Batali2:07 PM

current one is 4-5in

Kenneth Wiersema
Kenneth Wiersema2:08 PM

How I'm thinking right now, that should be good, so don't worry about it

Dana Batali
Dana Batali2:08 PM

12" v 24"

Dana Batali
Dana Batali2:09 PM

so to confirm, you don't want me to buy longer ones?

Kenneth Wiersema
Kenneth Wiersema2:09 PM

Yes, I don't want you buying longer ones now, I'll work around it right now

Dana Batali
Dana Batali2:09 PM

okie dokie

2018-02-12
Chris Rininger
Chris Rininger7:44 PM

I think we’re ok on this, but posting anyway: https://www.chiefdelphi.com/forums/showthread.php?threadid=162478

Kenneth Wiersema
Kenneth Wiersema7:48 PM

We don’t need to worry about it, the chassis is 27.5 as recommended, so we don’t have to worry about the minor protrusions fitting in that volume. And they shouldn’t cause a problem with the starting configuration.

Kenneth Wiersema
Kenneth Wiersema7:51 PM

Read it a bit further, and we might want to check bolt heads, but it sounds like that most teams were having issues with mounting the bumpers more than the stuff sticking out of the chassis

2018-02-13
Mark Tarlton
Mark Tarlton11:51 AM

I came across a recommendation for this cutting fluid for aluminum that helps avoid breakage when tapping holes. Anybody have thoughts about whether this is worth getting? http://www.tapmagic.com/product/2/tap-magic-aluminum

2018-02-14
Dana Batali
Dana Batali9:07 AM

my notes from first testing:
0. an exciting night with all systems actuating and sensing (with the exception of cameras, lights and IRsensor)

1. air leaks are a real issue. The three that we found were fixed but my sense is that was a testing bandaid.

2. the amount of time to fill the air tanks is substantial (minutes). Programming needs to provide team with a means to fill the tanks while in queue. (@Declan Freeman-Gleason proposed a new autonomous method). The testmode menu could also be applied.

3. the limit switch mounts for the flipper are mission critical, we need to make sure they are locked down. It's possible programming can mitigate failure by establishing current limits for this motor.

4. the scissor was very fast to get to the top with no load, less so with a cube. We haven't tested the key capability of stopping the scissor at various setpoints.

5. the entire machine feels dangerous. The battery access is perhaps the worst offender. Probably need to put some "danger" tape on access points that represent risk to limbs. The harvester's flipper in and out are rather intense. The scissor has lots of space to catch things. @Charlotte Larson Freeman found a torque wrench lying unattended in the chassis.

6. @Peter Hall reversed a couple of tubing channels to obtain correct "rest" behavior. Its possible that we should do this also with the harvester. I'm not certain if peter was keeping notes regarding the "official" tubing diagram. As changes are made an official diagram should be updated.

7. we need to get the IR sensor wired into the AnalogPort 2

8. it would be great if the pneumatics & electronics spreadsheet matched the diagram that peter worked off to build-out the first system. I believe @Ronan Bennett was updating it live last night, but we need to make sure that as things change, we are all on the same page.

Riyadth Al-Kazily
Riyadth Al-Kazily10:09 AM

It is extremely critical that the pneumatics/electronics/control spreadsheet be updated with all information before bag day, as we will not be able to make a duplicate robot without it. I believe that we should add additional information and diagrams to clarify plumbing subtleties. @Peter Hall please coordinate your team to gather the information.

brian_bonifaci
brian_bonifaci1:17 PM

The flipper needs a valve in the air line to reduce speed.

Riyadth Al-Kazily
Riyadth Al-Kazily2:20 PM

By flipper do you mean grabber? (The flipper is run by a motor)

Will Hobbs
Will Hobbs2:21 PM

I believe @brian_bonifaci is taking about the harvester

brian_bonifaci
brian_bonifaci2:24 PM

It was referred to by Dana above as "harvester flipper",

Will Hobbs
Will Hobbs2:29 PM

Got it

Peter Hall
Peter Hall2:48 PM

We can get that done this evening

Dana Batali
Dana Batali2:54 PM

By flipper I usually mean the articulator (wrist) part of the grabber. I also used (incorrectly) flipper in the context of the harvester. The hugging arms could be a little gentler, but this may not be a priority. Sorry for my flipper confusions.

2018-02-15
Kenneth Wiersema
Kenneth Wiersema2:47 PM

For anyone that saw Chris's post earlier about concerns about our frame perimeter, the team update 11 resolved that issue by allowing the small protrusions to be outside the 28" by 33" envelope this year, as how the rules has been previously made this illegal. We really didn't have to worry about it on our end, with the chassis's 27.5 by 32.3 outside perimeter, but it is something that should be kept in mind for previous years, as something like this could fowl us up. Team Update 11 details the change and the reasons for it. https://firstfrc.blob.core.windows.net/frc2018/Manual/TeamUpdates/TeamUpdate11.pdf

Mark Tarlton
Mark Tarlton4:07 PM

anyone interested in diving into the X-Carve / CNC may want to take advantage of this free slide rule offer. http://www.niagaracutter.com/speed-feed-slide Slide rules are handy tools for doing table lookups. This one in particular, can be used to determine cutting parameters based on router speeds, cutter diameter, material being cut, and the number of cutting flutes on the tool. To get the tool, signup at the link above. I can show people how to use it if interested.

2018-02-26
Will Hobbs
Will Hobbs9:12 AM

This is my list of what we need to do at today’s meeting. Please add in anything I missed.

Mount camera on harvester
Secure hooks in starting position
Make sure the flipper is fully functioning
Cut out the top of the second harvester
Bling???
Mock inspection
Single cable
Hardened steel rod on linear actuator
New bottom pulley

Paul Vibrans
Paul Vibrans10:51 AM

We should change to single cables on the competition robot's flipper and put a hardened guide rod on the linear actuator.

Kenneth Wiersema
Kenneth Wiersema10:53 AM

Does changing to a single cable require the pulleys to be changed again?

Declan Freeman-Gleason
Declan Freeman-Gleason11:17 AM

If engineering is considering changes to the robot, please focus on improving speed. As the robot is now, in my opinion (and from observation during testing), the flipper and scissor lift are not fast enough. Additionally, the harvester cannot eject far enough to work well in the exchange (but cube cycling to the switch and scale are higher priority).

Kenneth Wiersema
Kenneth Wiersema11:22 AM

That’s not something that can be easily addressed right now, especially with the current configuration of the robot, as I don’t think we can do those changes even with the mechanics getting all 6 hours of unbag time to do it, at least for Mt. Vernon. Depending on usage of the second robot there might be some solution we can work out on it before Glacier Peak, but I’m not confident about that.

Binnur Alkazily
Binnur Alkazily11:32 AM

can we speed up the motors for harvester eject? Increasing the speed by 25% might be a good test for now...

Mark Tarlton
Mark Tarlton11:35 AM

If that's not enough, we can try to fit larger wheels. Robot perimeter dimensions will limit the max wheel size.

Mark Tarlton
Mark Tarlton11:37 AM

The grabber wasn't picking up cubes on edge last time. The plate was interfering. Has that been resolved?

Rose Bandrowski
Rose Bandrowski11:42 AM

No, @Will Hobbs should we cut down the plate?? It sounds like it’s probably worth our time.

Rose Bandrowski
Rose Bandrowski11:42 AM

I haven’t cut carbon fiber myself nor have seen it done so I don’t know the time frame on that

Will Hobbs
Will Hobbs11:43 AM

I know we cut down one of the plates but we may need to cut a little more off

Will Hobbs
Will Hobbs11:44 AM

I think there are more important things we need to do first

Rose Bandrowski
Rose Bandrowski11:44 AM

Okay

Paul Vibrans
Paul Vibrans11:44 AM

Changing from double to single cables does not require different pulleys. It does require a change of parts on the linear actuator.

Kenneth Wiersema
Kenneth Wiersema11:47 AM

Ok, it should be first priority once the robot is un bagged is getting the linear actuator replaced and then getting the pulley system redone with the single cable

Declan Freeman-Gleason
Declan Freeman-Gleason12:03 PM

Harvester eject is at max speed

Dana Batali
Dana Batali1:40 PM

looking at line 80,81 of Harvester.java, i see that max output is currently set to +- .75... Bumping that to 1 should produce %25 more power.

Tanner Nalley
Tanner Nalley3:04 PM

@

2018-03-05
Mark Tarlton
Mark Tarlton6:07 PM

X-Carve update. I installed the new X beam and the new Z slide. The Z movements are way out of calibration and X-Carve has changed how they mount the rollers to the frame pieces. When I upgraded the X Axis beam, I followed the new instructions. I would like to remount the slide rollers on the Y-Axis to match but I ran out of Nylock nuts. I'll try to get in on Tuesday afternoon to address the remaining problems and test it all out.

2018-03-06
Chris Rininger
Chris Rininger8:55 AM

Mark Tarlton
Mark Tarlton9:59 AM

Were you proposing extending the telescoping pole during the match? It has to fit within the 55" max height at the start of the match. We could attach a lightweight, fixed height pole to the back of the scissor so that it goes up as the scissor lifts.

Chris Rininger
Chris Rininger9:55 PM

sounds like Paul also has an idea for attaching to the center of the lift - overall I think there's an opportunity for a high cam & I do think with practice that could help Will and James avoid misses when trying to place on the scale. Hard to say how much practice alone would help vs. having a camera, but you can bet the majority of elite teams have high cameras and practice using them

2018-03-25
Chris Rininger
Chris Rininger6:32 AM

After seeing the time we repeatedly spend tuning the latex tubing springs, I thought to myself there must be products that allow a more efficient process (I.e. without needing knots in the tubing). I found this as an interesting start. https://www.spearitco.com/ https://www.easierliving.com/exercise-tubing-by-rep-band.html?utmsource=bing&utmmedium=cpc&utmcampaign=PLA%20-%20Shopping&utmterm=4584551171165519&utmcontent=All%20Products

2018-03-27
Mark Tarlton
Mark Tarlton9:10 AM

Theraband is a well known provider of bands. A study was conducted on the material properties of the bands. one finding is that after pre-stretching, the force produced was less than before.. BUT, pre-stretching as few as 20 times will stabilize its performance. If we take this into account, we should be able to reduce the number of times we re-do the bands

Mark Tarlton
Mark Tarlton9:11 AM

https://academic.oup.com/ptj/article/81/8/1437/2857666 the link to the theraband study

Enrique Chee
Enrique Chee9:13 AM

@Mark Tarlton Thanks

Mark Tarlton
Mark Tarlton9:23 AM

Also, the bands produce more force during "loading" than "unloading". This explains why the lift may struggle to go up (bands are unloading) and then get stuck on the way down (loading).

Chris Rininger
Chris Rininger9:31 AM

@Mark Tarlton: that is super useful - thanks. New task for underclassmen: pre-stretch all latex tubing

Paul Vibrans
Paul Vibrans12:28 PM

Theraband is probably designed to have a lot of hysteresis. Spear gun rubber probably does not because energy release is on contraction.

2018-04-06
2018-05-04
Chris Rininger
Chris Rininger5:47 PM

I've heard several people are interested in swerve drives (2910's success this year may have something to do with that, though a LOT of that success was from excellent, well-practiced driving :slightlysmilingface:).

Here's a really good intro to swerve drive design (link to presentation within Chief Delphi post): https://www.chiefdelphi.com/forums/showthread.php?threadid=165331 ENJOY!

2018-05-05
2018-05-13
Kenneth Wiersema
Kenneth Wiersema7:51 PM

We still have spots open for the BARN class, please fill out the survey to say whether you are going https://docs.google.com/forms/d/e/1FAIpQLSedWLGtDQLSnP7B3P8E9-0Wm4eUxX7ucnet16Lk68qxgCS19Q/viewform?usp=sflink

2018-05-14
Chris Rininger
Chris Rininger1:53 PM

Hey, I was thinking the last mainstream shooting game was 2016, and we're due for another one in 2019. You could say 2017 had shooting (WE had a shooter), but so many teams skipped fuel that I would not say it was mainstream. Power Up had shooting, but it was quite limited.

So let's say there's a good chance shooting will be part of the upcoming game. As interesting as swerve drives are, I think vision assisted turret shooters are as or more cool. Seeing robots driving across the field, while using vision automation to move their turret automatically & make shots, is amazing.

If anyone else is interested in this, IRS created one in 2012 for Rebound Rumble, and they cover it in their engineering notebook from that year here: team1318.org/resources/ IRS did sort of OK that year at competitions, but their engineering notebook is really well done. Actually, all of the engineering notebooks are worth reading. Enjoy!

Darwin Clark
Darwin Clark4:16 PM

@Chris Rininger I could bring up the idea of vision-assisted 'shooting' in #atlas-restoration. After we hit the deadline for 4th of July parade we are looking to add more features to Atlas, and that would be a good training exercise.

Chris Rininger
Chris Rininger6:59 PM

@Darwin Clark It might be fun to get a vest with a distinctive reflective tape pattern detectable by a vision system, and then have the robot spin around to find the person wearing the vest & toss him/her the ball. Or demonstrate the robot picking the vest wearer from a small group formed into an arc.

2018-05-15
Darwin Clark
Darwin Clark8:42 AM

@Chris Rininger Yeah, we we thinking a smaller-scale application of that, such as a reflective sign, and passing that around the crowd. I do think the 'picking' from the crowd would be a fun exercise to do.

Chris Rininger
Chris Rininger11:18 AM

Sounds good - start simple, and then you could go in lots of directions from there. Maybe in a couple years you might have 3 different signs on lanyards (an X, a bullseye, and a smiley face, for example), and with a microphone integrated you could get Atlas to understand and execute commands. "Atlas, toss the ball to the bullseye"... And then there would be the opportunity to explain each element of that solution.

2018-05-22
Kenneth Wiersema
Kenneth Wiersema9:28 PM

Paul is offering to teach a class on making circular objects with bearing in the middle. The class is over 4 Mondays or Fridays starting in the first week of June. Each class only has two students with potentially one mentor overseeing the process. The class has a materials fee of $20. To sign up please email Paul and deliver the permission slip and fee at the first class. Please read through the document to find more details.

2018-05-30
Paul Vibrans
Paul Vibrans11:21 AM

The two spots in the Friday session are still available. Both spots must be taken or there will be no Friday session. The Monday session is filled.

The last chance to sign up is 10 AM, Thursday, May 31 for the Friday session that will take place from 3:45 to 5:45 PM on June 1, 8, 15 and 22.

Darwin Clark
Darwin Clark1:09 PM

Paul: I'm planning to sign up for the Friday class, just haven't sent an email to you yet. Sorry!

2018-06-02
Chris Rininger
Chris Rininger1:09 PM

Interesting breakdown of 3D print materials. Looking across it all, polycarbonate seems the most intriguing to me for FRC applications, though it requires more printer features for reliable prints than other materials. https://www.simplify3d.com/support/materials-guide/properties-table/?highlight=polycarbonate

2018-06-07
Kaedric Holt
Kaedric Holt9:45 AM

Pic of Mean Machines mill CNC.

Kaedric Holt
Kaedric Holt9:46 AM

And one of their router CNC, 8'*4' cutting table.

Enrique Chee
Enrique Chee10:01 AM

Thanks for sharing @Kaedric Holt

2018-06-12
Chris Rininger
Chris Rininger7:27 AM

A while back, I decided to learn some Fusion 360 fundamentals. I found Autodesk's own beginner tutorial videos to be mystifyingly poor, and so I looked around for other options. Paul McWhorter's series called "Learn Fusion 360 or Die Trying" worked well for me. The video production is imperfect, but the sequencing and the pace of the lessons is very well done in my opinion. By the time you get through the dozen or so lessons, you have some skills. Here's a link to the first lesson in case anyone's interested in starting to pick up F360 this summer: https://www.youtube.com/watch?v=y5tp4QXciK4

Harper Nalley
Harper Nalley9:10 AM

@Chris Rininger Do you think it would be a good offseason project to make videos for Fusion 360? Perhaps focusing more on the aspects of Fusion that are more applicable to robotics?

Chris Rininger
Chris Rininger9:13 AM

Good idea. Learning to do instructional videos like that, including recording presenter video/audio, recording on-screen video, etc. is a great skill. I think a quick win might also be to just find a bunch more existing videos that teach relevant skills.

Harper Nalley
Harper Nalley9:15 AM

True, but I have only found robotics centred videos for Inventor, none for Fusion.

Harper Nalley
Harper Nalley9:16 AM

I have screen recording software on my computer and I could try to make a video and see how it goes.

Enrique Chee
Enrique Chee10:14 AM

Great ! @Harper Nalley

Kenneth Wiersema
Kenneth Wiersema10:45 AM

I was going to write a series of topics on how I want CAD done during the summer. Videos might be good for basic skills but my primary issue is getting people to CAD properly and efficiently. I’m probably going to be learning a few things from BARN over the summer, so there might be changes to my ideas. Also robotics applications are simple modeling, assemblies and creating drawings, which all fall into the generic skills catagory

2018-06-16
Chris Rininger
Chris Rininger10:35 AM

@Kenneth Wiersema maybe you could start with an outline of the approach you want the team to align on, and for each step of the approach indicate the skills (e.g. 2D drawings with constraints, using parameters perhaps) needed to execute. And then the team can find videos teaching those skills OR if none can be found, then the team could create its own. And it sounds like @Harper Nalley is interested in contributing to that

Chris Rininger
Chris Rininger10:57 AM

Here's a new set of videos on CAM with CNC Routers created by a student from team 3647 (Aluminum Falcons). The team uses HSMWorks with Solidworks for CAM, but I've heard the CAM side of Fusion 360 is actually a slightly more robust version of the same software. Since there will be some CNC classes (though they'll be with a mill rather than a router) at BARN later this summer, this seems good to share: https://www.chiefdelphi.com/forums/showthread.php?threadid=165777

Chris Rininger
Chris Rininger8:34 PM

Regarding what to teach, here's a Behind the Lines episode on CAD that discusses whether to teach assemblies or drawings. I've (I think) linked to the relevant Q&A topic. It seems to me that assemblies may be the focus when parts are designed (or pulled in from COTS), but every team will need at least a couple people who know the software at the 2D drawing / constraints level as well, and that series I shared a few days ago really does a nice job of introducing the 2D side of things & parametric design. Video link I mentioned: https://youtu.be/cbB8qGlLKGU?list=PLIY-TB1MAu-X9ZcNqt-ot6JM2Z02zZ6L&t=4161

2018-06-20
2018-06-28
Chris Rininger
Chris Rininger11:08 PM

I ran across this mechanical linkage design/simulation software this evening - seems pretty neat! http://blog.rectorsquid.com/linkage-mechanism-designer-and-simulator/

2018-06-29
Chris Rininger
Chris Rininger12:20 PM

Could be used to figure out dimensions and geometry given constraints in the rules (e.g. designing a robot arm that follows the Power-Up rule of staying within 16" of robot perimeter)

2018-07-22
Chris Rininger
Chris Rininger10:54 AM

Hi, I'm not sure if there is interest, but I noticed there is an established CAD-athon for FRC folks from August 2nd 6pm to August 5th 8pm. Teams of 2 to 3 people participate - mentors & students welcome. Individuals can also sign up, in which case they'll be partnered with someone by the organizers. Here's a link to more information: https://www.chiefdelphi.com/forums/showthread.php?threadid=166041

2018-07-29
Chris Rininger
Chris Rininger3:13 PM

Here's a software-agnostic presentation on CAD / 3D Model & Drawing Fundamentals from team 254. It seems well done & it even includes worksheet-type exercises for skills building. I think the points made about the importance of 2D drawings in addition to 3D and the suggestion at the end of the presentation that a top-down design approach works better in FRC than a bottoms-up approach seem spot on. Top-down ~ start with rough whole robot design concept and iteratively update/refine it as components are refined. Bottoms-up ~ refine components and then figure out how to integrate them. Here's the link - hope some of you like it: https://www.team254.com/documents/cad-fundamentals/

Jack Chapman
Jack Chapman3:59 PM

Thanks for finding this, the 2d modeling section covers a lot of the material taught in technical graphics, I would really recommend reading if you haven't taken technical graphics yet

Kenneth Wiersema
Kenneth Wiersema5:31 PM

It's a good overview, but for 2d drawings it comes down to readability in the end. You really don't have to know the rules for dimension, but it needs to be readable by anyone, and enough dimensions should be included for any other necessary ones to be found. It does do a good job of describing basics, but not quite the main purpose for it.

2018-08-12
Chris Rininger
Chris Rininger11:11 AM

254 released their tech binder and build blog. The tech binder is an enlightening read. Several PNW teams like IRS and Shockwave create similar docs after each season to record what they did & why. Is this something our team might consider? https://www.chiefdelphi.com/forums/showthread.php?threadid=166176

2018-08-16
Harper Nalley
Harper Nalley10:46 PM

I’m trying to create one of these; I have a basic outline for.

2018-08-17
Chris Rininger
Chris Rininger10:04 AM

Thanks Lucas! I'm wondering if there isn't a way to link engineering notebooks created by students taking robotics as a class to the effort of creating something like this each season. Future Spartronics teams will benefit a lot from having a written-down reference of what past teams did. Otherwise, mentor memory is all we have, and (speaking for myself at least) I'm not sure how much will be retained that way.

Chris Rininger
Chris Rininger10:13 AM

I recommend looking at IRS's engineering notebooks (http://team1318.org/resources/) as well

Harper Nalley
Harper Nalley10:17 AM

I was thinking about compiling it from the leadership team’s notebooks. I’ll send you the outline I made.

Harper Nalley
Harper Nalley10:18 AM

THE NOTEBOOK SHOULD COVER

WHAT
What module did you do? Include a basic drawing and/or printed out isometric CAD view

WHAT ELSE?
What were the other ideas you played around with? Include a basic drawing and/or printed out isometric CAD view (this only applies if a CAD model already exists AND is detailed enough to use as a visual reference)
Also go over why you DIDN’T choose the other design(s). Try to include the pros and cons of each design and why, in spite of the pros, it wasn’t chosen.

WHY
This is similar to ‘WHAT ELSE’. You should go into why you chose the design you went with. Explain the pros and cons and why the pros outweighed the cons.

DESIGN
This should include full CAD drawings of the final design and any paper and/or CAD drawings of earlier iterations. Explain what changed and why.

MATERIALS
This should cover what materials you used, why, and where they came from.

IMPROVEMENTS
This should cover two parts: what improvements that were made through the competition season (if any) including CAD and/or hand drawings, why these improvements were made, and how.
The second part should cover redesigns and/or semi-major to major improvements that were planned but ended up being scrapped. Also, cover why they were scrapped.

TAKEAWAY
The final section should cover what went well, what went poorly, how you should have done things differently, and why.

2018-08-19
Harper Nalley
Harper Nalley6:17 PM

They fixed their robot with a hair drier

2018-08-27
Chris Rininger
Chris Rininger10:52 PM

Rev robotics announced some interesting products: https://www.chiefdelphi.com/forums/showthread.php?threadid=160494

I think the ultrahex shaft with the 5mm hex inside bore could be great for prototyping things like intakes and shooters. A drill + 5mm hex bit + a length of the ultrahex shaft seems like a quick and easy way to power a wheel.

And the 1" linear motion system seems like a good way to elevate something lightweight (like a high camera :slightlysmilingface: or maybe a climbing winch hook)

The other stuff seems pretty cool too (like the LED bling blinky controller)

2018-09-05
Kenneth Wiersema
Kenneth Wiersema4:56 PM

Chief delphi thread on drilling bearing holes with a drill press. https://www.chiefdelphi.com/forums/showthread.php?t=166372 Some of these might be worth looking into

2018-09-26
Mark Tarlton
Mark Tarlton1:55 PM

The team should consider getting a subscription to "G-Wizard" from www.cnccookbook.com to support our CNC work. This is a tool that helps select the right feeds and speeds for CNC, milling, and lathe work. You build up a tool library with all the mills, bits, cutters, etc. Then when you have work to do, you select the machine you're working with, the specific cutting tool, the material you're working with, and the quality of finish you're looking for. It will provide a set of recommended feeds and speeds plus an indication of how close to the 'edge of the envelope' you're running. You can then make adjustments interactively to zero in on the cutting settings. I did a 30 day free trial over the summer and thought it was pretty useful.

Mark Tarlton
Mark Tarlton2:00 PM

@Kenneth Wiersema -- Regarding the ownership of the Spartronics project in Fusion 360, I came across a post on changing project admins. https://forums.autodesk.com/t5/fusion-team-forum/how-do-i-change-or-add-a-project-administrator/td-p/6533906 It sounds like we can request help from Autodesk to get the admin switched. I suggest adding Coach as one of the admins plus one or more students. Then we can maintain the project over multiple seasons.

Kenneth Wiersema
Kenneth Wiersema2:56 PM

Doesn't apply to us, I found that or something similar, and that's using a team hub system, which we don't have. Will created the project in his name, and the projects are non-transferable between admin.

Kenneth Wiersema
Kenneth Wiersema2:57 PM

And to set one up would cost us money, and the big plus for Fusion 360 is that it's free

2018-10-14
Chris Rininger
Chris Rininger9:08 PM

@Cruz Strom & I were discussing the possibility of getting a grinding wheel that works for aluminum, and that drove me to refresh my memory about why a normal grinding wheel doesn't work with aluminum. I found an article that sums it up pretty well: "Compared with other metals, aluminum has a much lower melting temperature, so it melts easily. This low melting temperature causes the material to coat the abrasive disc [or grinding wheel] during grinding, covering the grit and exposing only bits of aluminum. This results in increased heat generation at the point of contact. Continued grinding produces even more heat, which produces more melting, which in turn causes the grinding operator to want to push down harder. Not only is this more labor-intensive, it results in more heat that causes loading. Longer aluminum chips coat the abrasive, which prevents the grain from doing its job."

Here's the article: https://www.thefabricator.com/article/finishing/gearing-up-to-grind-aluminum. It discusses several tools for grinding, deburring, and finishing aluminum. I did also find this deburring wheel on Amazon: https://www.amazon.com/dp/B00OXI1KZ4/ref=bissdptasn. And also this on the broader internet: https://www.sparkyabrasives.com/alumacut-wheels?gclid=EAIaIQobChMI27Gj4pCH3gIVkPhkCh3gCQwDEAAYASAAEgKMXvDBwE

2018-10-24
Camden Greenhalgh
Camden Greenhalgh7:17 PM

@Camden Greenhalgh has joined the channel

Miles Vilke
Miles Vilke7:38 PM

@Miles Vilke has joined the channel

Noah Solomon
Noah Solomon7:41 PM

@Noah Solomon has joined the channel

Max Hays
Max Hays8:14 PM

@Max Hays has joined the channel

Jack Scheiderman
Jack Scheiderman8:53 PM

@Jack Scheiderman has joined the channel

Merrill Keating
Merrill Keating10:25 PM

@Merrill Keating has joined the channel

2018-10-25
Kate Swietlik
Kate Swietlik7:29 AM

@Kate Swietlik has joined the channel

Jacob Preston
Jacob Preston12:55 PM

@Jacob Preston has joined the channel

Emerson Nicholas
Emerson Nicholas6:27 PM

@Emerson Nicholas has joined the channel

2018-10-26
Lane Johnson
Lane Johnson2:24 PM

@Lane Johnson has joined the channel

2018-10-28
Dana Batali
Dana Batali11:07 AM

here's the the latest version of affordable cnc milling machine we saw at tahoma hs:

https://www.tormach.com/1100m/

2018-10-29
Paul Vibrans
Paul Vibrans5:26 PM

Does it have capability to be used as a manual mill or must all actions be programmed first?

Paul Vibrans
Paul Vibrans7:54 PM

It surely looks possible, but who will spend the year to get the necessary experience to use the machine effectively and be able to train students?

Dana Batali
Dana Batali8:07 PM

not sure what your point is... are you saying that any cnc milling machine is a bad idea? Clearly we don't have funds to buy this tomorrow, but my sense is, this is a forward-looking tech that it would be unwise to ignore.

2018-10-30
Paul Vibrans
Paul Vibrans2:52 PM

It should be a part of a manufacturing class at the high school where there is a full time instructor and students learn to run it sometime other than during build season and the runup thereto. Multiply the difficulties of getting the X-carve running by the ratio of spindle horsepower.

2018-11-02
Thomas Eckhardt
Thomas Eckhardt10:49 AM

@Thomas Eckhardt has joined the channel

Stephen Reinhardt
Stephen Reinhardt10:51 PM

@Stephen Reinhardt has joined the channel

2018-11-03
Alexander Perkins
Alexander Perkins9:09 AM

@Alexander Perkins has joined the channel

Adam Rideout Redeker
Adam Rideout Redeker9:09 AM

@Adam Rideout Redeker has joined the channel

Jeffrey Tappen
Jeffrey Tappen1:36 PM

@Jeffrey Tappen has joined the channel

2018-11-04
Chris Rininger
Chris Rininger10:58 AM

For anyone new or who hasn't seen how the kit robot chassis we usually use is constructed, this video is well done in my opinion. https://www.youtube.com/watch?v=IKioQEbpZ9g

And a good reference for mechanisms is this presentation (just noticed this has been updated for 2018!): http://files.andymark.com/Appendages%20and%20manipulators%20in%20FIRST.ppt

Finally, for an experienced perspective about deciding what to do and how to do it, I'm a fan of this Strategic Design presentation: https://www.youtube.com/watch?v=dSXDV-UhhxU&t=779s

Mark Tarlton
Mark Tarlton12:51 PM

The BARN has just aquired a CNC lathe and upgraded the big mill with new CNC controls. Both machines use hardware and software from http://www.CentroidCNC.com . The machines are controlled through a touchscreen UI that support four modes of use: loading gcode programs (e.g from fusion 360), line by line entry of gcode commands, direct movements using the touchscreen and an interactive programming mode where users compose sequences of operations via a "conversation" with the controller. Here's a video of conversational programming of the lathe. The mill supports a similar functionality. https://www.youtube.com/watch?v=rEY3uKOuPZQ

2018-11-05
Dana Batali
Dana Batali10:56 AM

Company in north bend supplies FRC teams

https://youtu.be/8OTwT0WFBmg

Includes plasma cutting options

2018-11-07
Ulysses Glanzrock
Ulysses Glanzrock9:12 PM

@Ulysses Glanzrock has joined the channel

2018-11-08
Chris Rininger
Chris Rininger9:43 PM

Here is the best new FRC resource I’ve seen in a while. *Roboting: A Guide for Total Noobs.” Learn to connect the thing to the thing and make it move and do the thing... LOTS of pictures, and relatively few words. It says for noobs; it’s really for everybody. Take a look! https://www.chiefdelphi.com/forums/showthread.php?threadid=167193

2018-11-09
Dana Batali
Dana Batali8:25 AM

This should be required reading for everyone on the team. Best single resource I've seen!

Mark Tarlton
Mark Tarlton11:19 AM

I believe that the BARN's plasma table is from cncrouterparts. Unfortunately, it's still not working properly but I think that's next on the list of work for the CNC repair team now that the mill and lathe are coming in line.

Chris Rininger
Chris Rininger2:49 PM

We might even think about getting a couple copies printed & bound and set them out in the robotics room for reference and incremental perusing/learning. Sound reprographics is a sponsor. :slightlysmilingface:

2018-11-14
Dana Batali
Dana Batali2:07 PM

new brushless motor this year ($40) with 3-phase hall sensors

http://www.revrobotics.com/rev-21-1650/

and controller ($75)

http://www.revrobotics.com/rev-11-2158/

Enrique Chee
Enrique Chee6:28 PM

Thanks @Dana Batali

Mark Tarlton
Mark Tarlton7:32 PM

Here's a new 3d printer component announcement for printing with stronger materials. https://3dprintingindustry.com/news/lulzbot-releases-hs-series-tool-heads-for-high-strength-3d-printing-143335/

Chris Rininger
Chris Rininger10:59 PM

“NEO Brushless Motor is a sensored brushless motor with mechanical mounting and output power similar to a CIM motor. You can find more info about these devices on the REV Robotics website.” Interesting!

2018-11-15
Chris Rininger
Chris Rininger1:51 PM

@Kenneth Wiersema @Cruz Strom @Jack Chapman Did we pre-order some samples of the new powerful brushless motor & controller? It sounds like they're going to be as significant a new addition to the FRC robotics kit as the 775pros (for which we were late the party). With the weight difference vs. CIMs/miniCIMs and monitoring/control via the hall sensors, they could become the new drive train standard, though this year it is more likely teams will use them for mechanisms to get used to them. Anyway, I recommend pre-ordering some (maybe 4 motors & 4 controllers to start?) - the USB connectivity/configuration makes it seem like these could be really useful when prototyping as well.

Chris Rininger
Chris Rininger1:53 PM

I recommend someone monitor this thread: https://www.chiefdelphi.com/forums/showthread.php?t=181035 Teams are testing them out, sharing data & videos, etc. Good idea to be in on a major new innovation like this. It doesn't need to be one of you - I recommend delegating to another leadership team member & have them report back to you. Perfect kind of task to delegate.

Chris Rininger
Chris Rininger2:36 PM

Couple pictures to share:
1) PC client UXs of the new Rev SPARK MAX Motor Controller for motor config and also real-time control.
2) Picture of the new NEO brushless motor side-by-side with other legal FRC motors

2018-11-23
Cruz Strom
Cruz Strom9:19 PM

Hello Mechanics Subteam,
I hope all of you have had a wonderful Thanksgiving. The other captains and I have decided that we would like to put together extra meeting dates in the Mechanics shop to help get things done before Build Season. The Mechanics, Electrical and CAD subteams all have tasks that need to be finished. All of these meetings are optional. Below are the dates:
Monday 11/26 1:45-4:00
Monday 12/3 1:45-4:00
Wednesday 12/5 3:10-5:00
Monday 12/10 1:45-4:00
Please fill out the survey to whether or not you can come to the meetings by Sunday at 12:00 P.M. (Noon). Please fill out the survey even if you are not planning to come to the meetings.
Here is the link to the survey:
https://goo.gl/forms/OD3h6wo5xbVugC8L2
If you filled out the link in the email I sent out, please do not fill out the survey again.
Thank you,
Cruz Strom

2018-11-26
Mitchell Teresi
Mitchell Teresi3:41 PM

@Mitchell Teresi has joined the channel

2018-12-01
Jack Chapman
Jack Chapman5:16 PM

Info on motors/gearboxes
Sorry about the delay, here are the resources I said that I would provide:

Here is my presentation
https://docs.google.com/presentation/d/1oztXHVjQB4rdA4rZxF8mlQ1BllLrTajUi9ej9kmxozA/edit?usp=sharing

Here is Kenneth's original presentation
https://docs.google.com/presentation/d/1eJjTbcgL963iIE-crkDxifbasIihyMDhWBfanfzC8v4/edit?usp=sharing

the jvn motor calculator
link.vex.com/vexpro/jvn-design-calculator

The versaplanetary instructions on how to assemble a gearbox
https://docs.google.com/gview?url=http://link.vex.com/vexpro/pdf/VersaPlanetary-v2-User-Guide&embedded=true

The vex article on how to spec motors
http://motors.vex.com/introduction

Here is the presentation that Chris found, that you all should read. I found slides 1-61, 74-122 122-132, 138-139, 141, 148-177, 219 especially relevant to mechanics
https://www.chiefdelphi.com/media/papers/download/5585

Here is a good presentation that Chris found on the math needed for making different engineering design decisions, including how to use a tool like the JVN calculator. https://www.chiefdelphi.com/media/papers/download/5607

2018-12-02
Chris Rininger
Chris Rininger12:21 PM

Another good calculator similar to JVN but covering some different bases is the AMB Design Spreadsheet v2: https://www.chiefdelphi.com/media/papers/3485?

Andrew Peterson
Andrew Peterson10:10 PM

I will not be able to make it to the meeting tomorrow

2018-12-05
Chris Rininger
Chris Rininger1:43 PM

Here’s 2910’s CAD release from last season. As cool as their swerve drive is, they were successful because they had a great overall design. Their intake was “touch it ownit”, and their lift/climber performed consistently great. There are things we can learn from studying their design. The CD post has some good renders you can zoom in on... https://www.chiefdelphi.com/media/photos/46673

Chris Rininger
Chris Rininger2:37 PM

Here is a good presentation on the math needed for making different engineering design decisions, including how to use a tool like the JVN calculator. https://www.chiefdelphi.com/media/papers/download/5607

Andrew Peterson
Andrew Peterson3:14 PM

I will not be at the meeting for Mechanics today until 5:10

2018-12-10
Mark Tarlton
Mark Tarlton1:24 PM

I will be late today .

Mark Tarlton
Mark Tarlton6:37 PM

Sorry I wasn't able to make it at all today.

2018-12-13
Mark Tarlton
Mark Tarlton2:58 PM

First print with the new Onyx 3D printer just started. Should take 35mins.

Chris Rininger
Chris Rininger3:33 PM

times up; let's see it :grin:

Mark Tarlton
Mark Tarlton3:36 PM

This is it

Paul Vibrans
Paul Vibrans3:37 PM

Can you break it?

Chris Rininger
Chris Rininger3:38 PM

yes, agree, please get out the hammer & take some video

Mark Tarlton
Mark Tarlton3:46 PM

Not easily. It's pretty stiff. I can only twist it slightly, and if I try to break it in to, it deflects about 45 degrees but it takes a fair bit of force to make it bend that much.

Mark Tarlton
Mark Tarlton3:48 PM

Slack is already complaining about being out of storage :whitefrowningface:

Jack Scheiderman
Jack Scheiderman3:50 PM

What was your infill?

Mark Tarlton
Mark Tarlton3:52 PM

Triangular infill, 37% density, 4 layers on floor & roof, 2 layers on the walls. layer height is 0.125mm

2018-12-14
Doña Keating
Doña Keating5:10 PM

@Doña Keating has joined the channel

Mark Tarlton
Mark Tarlton6:52 PM

Here's a look at Paul's gear. I can't see any layer lines but I do see a gap between the interior and exterior surface for both the shaft an gear rings. I expected to see a cap on those surfaces. Also, the teeth appear to be more rounded than the model shows. I tried squeezing the outer ring with thumb and forefinger and get a small deflection. Surface finish is pretty nice.

2018-12-15
Mark Tarlton
Mark Tarlton2:38 PM

https://photos.app.goo.gl/ffijTGMMFAfm5SiP7. Kenneth's part plus support structure. The right side of the object is the face attached to the support in base. That's why it looks rough. The left side is what the other faces look like.

Mark Tarlton
Mark Tarlton2:43 PM

I think Paul's going to queue up another set of parts tonight. If others have something they want printed, put it in the print queue and I'll lay them out and get them started later tonight. The one constraint is that the layer height has to be the same on all parts that are printed together, so I may need to do multiple batches if there are differences.

Chris Rininger
Chris Rininger5:08 PM

@Paul Vibrans please try adding to the print I already have queued rather than creating a new one to see how it works (if possible)

Mark Tarlton
Mark Tarlton6:18 PM

I did that with Kenneth and Dana's models. It works fine. Once all the models are added together, it repeats the slicing operation. Then I prep the bed and launch the print operation.

Mark Tarlton
Mark Tarlton6:19 PM

There's a firmware update that I need to apply before I do the next print.

Mark Tarlton
Mark Tarlton6:20 PM

I will also look at the job queue and do another merge if possible.

Chris Rininger
Chris Rininger7:14 PM

ok, thanks. I removed my build from the queue, and I created a Build called "Multi-part Build - Add to This". One thing learned: it seems like you need at least two parts in a build to save the build to the library.

I'm curious about something: Can another person update the build I added to the library? Hope so. Also, can another person remove a model from the build I initiated (i.e. in favor of something higher priority that came up & needed to be printed). Worth trying out.

Mark Tarlton
Mark Tarlton7:15 PM

The story with the print queue is that printing can be initiated either from the Eiger webpage OR from the printer's built in user interface. So far, everything I've done used the web page. I just tried the Printer UI buttons and I see the job that Chris has queued up. In either case we don't have to have a PC/laptop dedicated to the printer (which is very nice!).

Mark Tarlton
Mark Tarlton7:30 PM

Re: saving builds -- A "Build" is a collection of two or more parts". If you create a build and then delete all but one part, it will go back to being just a single part -- and it may be a COPY of the original part. ( This isn't how I originally thought it worked )

Mark Tarlton
Mark Tarlton7:34 PM

When I saved the modified build, a COPY of the build was saved. Your original build was left unchanged. I was then able to "Print --> Add to Queue" your version of the build. In the queue, it shows my name (since I'm the one that added it).

Mark Tarlton
Mark Tarlton7:35 PM

All in all, it seems to behave in a reasonable fashion. :+1:

Mark Tarlton
Mark Tarlton7:44 PM

... and the version of your build that I added to the queue was yet another fork of your build. So, only you can change your stuff. Any changes get done to a personal, forked version of the original. If you try to make a change to my version of your original, I think it will create a fork of my version with the same name and keep your original version unchanged. The number of "builds" can grow pretty quickly. I've started deleting the extras to reduce clutter.

Mark Tarlton
Mark Tarlton7:50 PM

Ok, I'm changing my opinion. A "Build" is a collection of two or more parts. A single part won't be saved in the list of builds.

Mark Tarlton
Mark Tarlton7:57 PM

Caution: When laying parts out on the build plate, try to keep the back 1 cm or so clear. The printer uses that area when it's clearing the print head.

Paul Vibrans
Paul Vibrans8:11 PM

I added 6 spacers in front of everything. My layer height must have been OK because it accepted the parts.

Chris Rininger
Chris Rininger8:20 PM

As I look at the illustrated build area in Eiger, it seems like the back is unavailable. Take a look at the Multi-part build in queue... Do you think I need to move the parts forward some?

Mark Tarlton
Mark Tarlton8:22 PM

I think leave it as is and then we'll know for sure. You're probably right.

Mark Tarlton
Mark Tarlton8:22 PM

Ok, Ready for the print to start?

Chris Rininger
Chris Rininger8:23 PM

I don't see Paul's spacers

Chris Rininger
Chris Rininger8:25 PM

Also, you have another SpaceX coaster in queue - if you want two of them could just drop a second one into the next print since there is space

Chris Rininger
Chris Rininger8:25 PM

I just had it in there to try out multi-part... plus it's cool lookin

Mark Tarlton
Mark Tarlton8:26 PM

If you open the build up, you'll see it. I just started the slicing process -- I think that's when the thumbnail gets rendered. -- Yeah, I'm going to delete the extra stuff from the queue.

Chris Rininger
Chris Rininger8:28 PM

yep, you're right - I see them now

Mark Tarlton
Mark Tarlton8:28 PM

I launched the print job.

Chris Rininger
Chris Rininger8:29 PM

looks like there are rafts under the spacers (?) - doesn't seem like that should be needed

Mark Tarlton
Mark Tarlton8:34 PM

There's a brim but I don't think a raft. The 3D guys at the barn recommend using brim always since initial adhesion is critical and one of the common failure modes. It adds just a few minutes. I left it off the coaster as an experiment. Since the spacers are small, I think they should be printed with a brim.

Chris Rininger
Chris Rininger8:36 PM

got it - thx - I'll have to look up the difference now LOL... UPDATE: I found the explanation here: https://www.simplify3d.com/support/articles/rafts-skirts-and-brims/

Mark Tarlton
Mark Tarlton8:44 PM

It's printing the first layer now. On the Spartronics thing, the corners of the gears are lifting just a bit. That's probably an important heuristic -- if there's a sharp corner, it probably needs a brim.

Mark Tarlton
Mark Tarlton8:47 PM

First layer. Note the bubbling at the corners. No brim used.

Mark Tarlton
Mark Tarlton8:48 PM

.. The "purge line" is visible in the background. There's no interference with the eiger print region.

Paul Vibrans
Paul Vibrans8:58 PM

The projection of that unsupported first layer is not stable. A brim can curl and we don't care.

Paul Vibrans
Paul Vibrans9:04 PM

Is it printing the first layer of all parts before it moves on to subsequent layers? If so, that means a "cold joint" between all layers. On critical parts, we may want to make one part builds or assure the critical load paths are parallel to the layers.

Mark Tarlton
Mark Tarlton9:16 PM

That's right, a cold joint. There's also a built in fan to cool the material so that it stays in place after it comes out. The tradeoff is between cold joints and sagging. Taking load paths into account when orienting the part on the build plate is recommended.

Chris Rininger
Chris Rininger10:36 PM

I added the brim option to the part for next time - raised the cost from 66 to 76 cents BTW. Thanks for explaining that.

Chris Rininger
Chris Rininger11:10 PM

Learned something: I changed the logo to have a brim, but in the build with the parts currently being printed, the part was not updated. That could be because a print is in progress and the part will eventually refresh. Or it could be that, to include an updated part in a build, one has to remove it from the build and re-add it back. Something to keep an eye on & confirm how it works for sure.

Mark Tarlton
Mark Tarlton11:21 PM

Right. The build belongs to me. I had to go back to that build, delete the old logo part and add your new version. Then I see the brim. My impression is that the system uses more of a 'version control' model rather than a 'file name' thing. The older version is happily printing while I created a new version of the build.

2018-12-16
Mark Tarlton
Mark Tarlton12:02 AM

https://photos.app.goo.gl/kibAk3Qyi96gWt3Y6 photos of latest parts. Features with an inner and outer wall that's close together don't get capped very well. It seems to be a chronic problem. We need to look into this and see what others are doing about this.

Chris Rininger
Chris Rininger9:49 AM

I’ll be interested in hearing how easily those spacers separate from the brim. The logo looks decent, but not as precise as the ABS prints - maybe it’s just a tad too small in scale. The SpaceX coaster looks great IMO!

Mark Tarlton
Mark Tarlton10:32 AM

If you zoom in on the SpaceX piece, you'll see gaps between the hexagons that shouldn't be there. That's what's really troubling me. I think it's a problem in how the slicer works.

Chris Rininger
Chris Rininger11:02 AM

I see what you mean. I looked at the Internal View of the part, and it appears as it was printed. There's an "expand thin features" option, explained as "Select this if your part has extremely thin walls you need to preserve at the expense of dimensional accuracy". I tried it on a clone of the coaster, and the Internal View looks better as far as the walls of the hexagons being butted more closely together. Could probably send a picture to MarkForged support & ask how to address the issue.

2018-12-18
Chris Rininger
Chris Rininger9:50 PM

Seems like the printer is set up other than researching or working with MarkForged support on the gap issue discussed in this thread (which may not even really come into play on a lot of parts). As far as a workflow including a different printer (presumably our ABS-printing Makerbot Replicator 2x) in front of the MarkForged for prototyping/perfecting a part prior to printing in Onyx, it seems like we'll need to develop that on the fly in January. Coach showed me that we have an earlier original Replicator, and research indicates we could get that one up and running as well (see posts by CrazyHamSales in this thread for how: https://www.3dhubs.com/talk/t/help-printing-with-makerbot-1-dual-extruder/13984). Would probably need to buy Simplify3D software, and I have a contact for an edu discount if we want to go there.

2018-12-19
Chris Rininger
Chris Rininger2:37 PM

Spectrum (team3847) publishes a lot of great info, and this latest on Minimum Competitive Concept is worth a read. It covers very well how to keep things relatively simple and still be very competitive. https://www.chiefdelphi.com/media/papers/3514?

Dana Batali
Dana Batali2:56 PM

@Mark Tarlton: regarding the spaceX between the walls: it is my sense that this is where wall-thickness intersects with infill. If you had a 100% infill you wouldn't need the wall and top/bottom thickness settings. Similarly, if you had a larger wall thickness, one hopes that the holes go away. Sorry if this is old news or off-the-mark.

Chris Rininger
Chris Rininger5:36 PM

I think, as you say, wall thickness and infill need to be tweaked until the internal layered view in Eiger looks right. I asked the question (plus a question about gear applications) on Chief Delphi, and there were a few helpful responses we should review and incorporate into our practices. @Mark Tarlton @Paul Vibrans @Dana Batali @Kenneth Wiersema @Chris Stanley https://www.chiefdelphi.com/forums/showthread.php?threadid=186613

Chris Stanley
Chris Stanley5:37 PM

@Chris Stanley has joined the channel

Mark Tarlton
Mark Tarlton7:11 PM

The gears were printed with wall thickness of 4 and floor/roof of 4 ( I think). Solid fill would obviously eliminate the problem but it would be better if we could get a handle on capping narrow regions. AFAIK, the fill settings apply to the entire part -- so the SpaceX coaster would fill the entire base just to get the top hex grid to look right. Going to thinner walls would be worth trying but, once again, it would apply to the entire part.

Another thing to try is thicker layers. I think Paul used very thin layers to get fine details.. thicker might fill better and not droop in on the top. If we had more control of slicing, I think we could dial in the individual regions better.

Regarding tapping of screw holes, I just received an assortment of threaded brass inserts that I was going to test. Sounds like they should work nicely.

2018-12-23
Chris Rininger
Chris Rininger10:18 AM

Here's a video playlist on FRC prototyping, in case any of you get spare time & are interested. There are a bunch of really short videos at the beginning, which (I think) makes it fun to watch: https://www.youtube.com/playlist?list=PLsiEJAZgdF8LPWDAYBeQJ-EvkUpK295ra

2018-12-27
Mark Tarlton
Mark Tarlton11:08 PM

The Stirling Engine is nearly complete. Just needs final adjustments and it will be ready for it's first run. This was a summer project by some team members at the BARN. It started out as lumps of brass and aluminum.

Mark Tarlton
Mark Tarlton11:10 PM

https://photos.app.goo.gl/hVsBCwTmXRKckzRp9. More photos from tonight's work.

2018-12-28
Violet Advani
Violet Advani6:20 AM

Awesome! Looks great :+1::skin-tone-3:

2019-01-04
Mark Tarlton
Mark Tarlton5:22 PM

The MarkForged 3D printer is up and running in the team room. @Paul Vibrans gears are printing and should be finished tonight. It doesn't show up on the network right now because I changed network connections after launching the print job in hopes that the school IT folks would enable the ethernet jack by the printer. If you want to read up on how to use the printer, go to https://support.markforged.com/hc/en-us/articles/115000051710 Look under "Desktop printers" --> "Onyx One" --> "Operation" and read the individual topics.

Enrique Chee
Enrique Chee5:28 PM

Thank you Mark !

Declan Freeman-Gleason
Declan Freeman-Gleason5:34 PM

If you're trying to connect to an ethernet jack by where the filing cabinet was, then there is one jack that actually works there. It is currently plugged into the CAD desktop computer. I think the team has some ethernet switches in the programming drawers, so it might make sense to just attach a switch and share the one working jack (if we can't find more working ones). Sorry if this isn't applicable for the situation, I just thought I might be able to save an email to the school IT department.

2019-01-05
Harper Nalley
Harper Nalley8:19 AM

Harper Nalley
Harper Nalley8:19 AM

Size rules

Sunny Gregson
Sunny Gregson11:21 AM

@Sunny Gregson has joined the channel

Chris Rininger
Chris Rininger7:36 PM

Pretty sweet velcro hatch panel ejecter from team RI3D FIRST Capital. https://www.youtube.com/watch?v=QIcJUxHfVe4

Want more like this? Here's the link to a Robot In 3 Days teams spreadsheet (with links to their youtubes, etc.): https://docs.google.com/spreadsheets/d/1Yubvuo6aWE8AHZ0so7Tl3DviPnLrRayZYgGGljWgL78/edit?usp=sharing

Enrique Chee
Enrique Chee8:41 PM

@Chris Rininger thanks!

Riyadth Al-Kazily
Riyadth Al-Kazily10:03 PM

Interesting concept for climbing "stairs". Maybe adaptable to a wheeled robot, by adding a "belt drive" system that can flip out over the front to pull the robot up on a step (or platform): https://youtu.be/VoqLz2RHDR0

2019-01-06
Chris Rininger
Chris Rininger1:05 AM

LOL RI3D Snow Problem did almost exactly the same thing - seems like a winning design for grabbing and placing hatch panels using the velcro: https://www.youtube.com/watch?v=i0jOJpt9V4

Chris Rininger
Chris Rininger1:08 AM

And then there's also this :slightlysmilingface: https://twitter.com/i/status/1081760261969719297

assets/img/USLACKBOT
assets/img/USLACKBOT1:18 AM

This message was deleted.

Mark Tarlton
Mark Tarlton10:48 AM

@Chris Rininger - I get a 'video unavailable' link

Chris Rininger
Chris Rininger11:21 AM

I shared this in a thread with Mark earlier, but I think it's really good, so sharing here more broadly. This is the day 1 review with RI3D team FIRST CAPITAL (from Philly - get it?). This group is clearly very experienced and they cover what they're thinking and what they're doing for all aspects of the game. I think there are a lot of insights generally about things we can stand to learn & develop on our team from this: https://www.youtube.com/watch?v=rRVNAJKsZ28

Chris Rininger
Chris Rininger11:35 AM

Another RI3D video from University of Waterloo: https://www.youtube.com/watch?v=0KkqVasvWPM

Chris Rininger
Chris Rininger11:37 AM

Today into next week, there will be a lot more coming out from RI3D, and it is sort of like free prototyping. Links to the teams are in this spreadsheet: https://www.youtube.com/watch?v=0KkqVasvWPM

Chris Rininger
Chris Rininger8:07 PM

Let's make this the climbing thread (?). Here's one someone found on CD: Climbing system video someone shared on CD: https://www.chiefdelphi.com/t/climbing-robot-system/337801

Riyadth Al-Kazily
Riyadth Al-Kazily8:11 PM

I am very interested in the robot built by Team 100 for 2016 - Stronghold. Their drivetrain incorporates wheels and a belt to climb over obstacles. I think if combined with a lifting mechanism (ie, pushing down with our elevator or something) to get the front wheel up to the step level, then the belt drive will carry the robot up without it getting stuck. Images here: https://www.team100.org/robots/ And video here: https://youtu.be/Vu9n-GHdGZ8

2019-01-07
Binnur Alkazily
Binnur Alkazily7:55 AM

RI3D FIRST Capital Hatch Angular Displacement Test: https://youtu.be/ZSrDXWIV6cg

Andrew Peterson
Andrew Peterson10:18 AM

I can only stay to help out with game elements today until 3:30

Mark Tarlton
Mark Tarlton11:01 AM

The new 3D printer is a little unusual in that the printer bed is not heated. Instead, the print bed is made of "Garolite" -- a composite material that works well when printing nylon. MatterHackers shared a 4 minute video on Garolite print beds at https://www.youtube.com/watch?v=w0uz26FN9mw It has info on the material itself, how to use it, and problems to watch out for.

Jake Benjamin
Jake Benjamin12:27 PM

@Jake Benjamin has joined the channel

Paul Vibrans
Paul Vibrans2:00 PM

It looks like we can climb to the second level in the HAB if we choose the correct chassis dimensions. I have attached a layout that shows this with a 34 inch wheelbase, 4" wheels, and the mid wheels displaced 2" from the longitudinal center. Center of gravity for the climb must be between the closely spaced wheels.

Dana Batali
Dana Batali2:25 PM

curious what this means to the width of the robot assuming we max out our perimeter?

Paul Vibrans
Paul Vibrans2:28 PM

Obviously it gets smaller. I am working with 42" long by 18" wide in my layouts going forward.

Paul Vibrans
Paul Vibrans2:32 PM

Climb to the third level requires special equipment, but the same frame geometry provides sufficient bumper clearance to the HAB when the robot is tipped back to get wheels on the top surface.

Dana Batali
Dana Batali2:35 PM

How, in your experience, will an 18" width affect maneuverability? If fast pickup/dropoff is high-priority, is this a concern? (I imagine this may be hard to predict in advance)

Dana Batali
Dana Batali2:37 PM

in any event this is a great option to consider!

Mark Tarlton
Mark Tarlton3:49 PM

Yes, we used that one to make sure we could get out ok and that no ports were blocked. We wanted the printer by the other wall without draping cables. The new wall port got hooked up today so we're now good to go. Connecting a hub over there with some patch cords might be better than school wifi... especially for people like me that just occasionally need to connect a laptop to the net.

Paul Vibrans
Paul Vibrans3:58 PM

Turning will be more difficult because of the narrow track and greater rotational inertia from the long chassis. Omni wheels are recommended for the wheels at the ends to reduce scrubbing forces in turns and to make the rotational center consistent depending on which end is on the floor as a result of center of gravity shifts resulting from the game piece handling gear.

Paul Vibrans
Paul Vibrans7:51 PM

Working on a layout of an articulated arm that can reach everything and carry a spinning roller grabber and a hatch holder.

Cruz Strom
Cruz Strom8:04 PM

Hello Mechanics team, tomorrow and Wednesday after school, we will continue to build the game elements. We will start tomorrow and Wednesday (Tuesday 8th and Wednesday 9th of January) at 3:15 (After School) and work until 4:30. The full team meeting does not start until 4:30. Please come if you can. Thanks, Cruz

Paul Vibrans
Paul Vibrans10:02 PM

My thoughts on an elevator vs. an articulated arm for handling game pieces in Deep Space.

Chris Rininger
Chris Rininger11:27 PM

Playing w/ F360 a little bit. Ramp bot concept. If you have an open front (for cargo balls), and if you could find a way to use the back ramp bottom for processing hatch panels, and if you could find a way to optimize where the joints are, something like this could be used for the "everything low + help another climb to L3" bot

Chris Rininger
Chris Rininger11:28 PM

has someone confirmed if L1 is a 11.5" ramp + 30" platform, or is it a 11.5" ramp + 18.5" deep platform = 30" total - this assumes the latter because the manual implies it

2019-01-08
Chris Rininger
Chris Rininger6:52 AM

One of the RI3D teams (FIRST CAPITAL I think) is doing single stage elevator + 4-bar, and it looks promising. Here's a video - you can skip the first 5:30, and the main walkthrough of the robot ends around 16:30 https://m.youtube.com/watch?v=Kj3O6i54gIw All of their mechanisms seems pretty simple & clever - recommended.

Chris Rininger
Chris Rininger7:03 AM

just want to double check: I'm getting a warning that storage space is used up... is the picture of the ramp bot concept I shared visible to you all?

Cruz Strom
Cruz Strom7:35 AM

Yes, I can see it

Chris Rininger
Chris Rininger8:10 AM

RI3D Roundup + 118's Everybot! This is free analysis & prototyping - let's use it! Watch these and reply to this thread with anything gleaned.
RI3D 1.0 - https://www.youtube.com/user/robotin3days
FIRST Capital: - https://www.youtube.com/watch?v=9SUDbN1HfjI
Big Orange Robotics - https://www.youtube.com/channel/UCh5q5xnOPqQFwtNC3XEa2Q
ZouKeepers - https://www.youtube.com/playlist?list=PLjd4bOKQZpgkmDuFL2kTmdiwtZCtmjaYs
Snow Problem - https://www.youtube.com/channel/UCBv8vHAnG1f9IeK1CrZCw
GreenHorns - https://www.youtube.com/channel/UCurV1YfezeLOlOivgYXlhgw
University of Waterloo - https://www.youtube.com/channel/UC5cf1P5wAczI1YubbbDKtxQ
University of Michigan - https://youtu.be/zlNXkQe0BQU
FRC 118's Everybot - https://ccisdrobonauts.org/?p=everybot

Chris Rininger
Chris Rininger8:12 AM

I've only watched FIRST Capital so far, and I'm really impressed. They're doing an elevator + 4-bar lift, and their panel and cargo handling mechanisms seem simple and effective. Their approach to climbing to L2 seems very, very effective. I think this might be the best RI3D robot I've ever seen - it could win a competition probably.

Riyadth Al-Kazily
Riyadth Al-Kazily9:40 AM

I think that lowest platform is not the correct dimension. The flat part should be wide enough for an entire robot to sit on it. Check the field dimensions on the drawings and other resources, available here: https://www.firstinspires.org/robotics/frc/playing-field

Mark Tarlton
Mark Tarlton10:12 AM

Lots of good ideas. I worry about that design tipping over backwards during the climb. Even though they've moved the battery forward, it could be tippy when they lift the front end off the ground.

Paul Vibrans
Paul Vibrans11:22 AM

The whole lower ramp is only 36" front to back, including the slope. Getting all of the wheels on it will be difficult.

Paul Vibrans
Paul Vibrans11:36 AM

Looks mechanically messy to me

Chris Rininger
Chris Rininger11:43 AM

That's how I read the drawing in the manual, but I think it is off (& Riyadth is right). If you look at drawing TE-19105 in the the following file, it indicates the flat platform is 36" deep, and ramps are in addition to that. https://firstfrc.blob.core.windows.net/frc2019/DrawingPackages/TeamDrawings-Reduced.pdf

Chris Rininger
Chris Rininger11:55 AM

Well, it is an ri3d robot... Do you think 1-stage elevator + 4-bar might work better (I’m thinking lateral extension) than 2-stage elevator or elevator/arm hybrid? The guy leading it is head mentor of 225 Tech Fire, and they were an elims alliance leader (picking team) in their division at World Champs last year, so there might be things to learn for us here.

Paul Vibrans
Paul Vibrans12:45 PM

I prefer an all arm configuration. And their lift cylinders are going to bend rods.

Paul Vibrans
Paul Vibrans12:53 PM

Drawing 19031 clearly shows the flat top to be 36" wide excluding the slope.

Chris Rininger
Chris Rininger3:36 PM

How hard are arms to program/tune? With all the different targets on the field and the likely need to use the white lines and reflective tape to line up to those targets, it seems like programming is at risk of being overloaded. It'd be good to get their take on doing an arm for the first time and handling all the things needed for high/med/low targets.

Ryan Olney
Ryan Olney6:42 PM

@Ryan Olney has joined the channel

Mark Tarlton
Mark Tarlton6:48 PM

@Paul Vibrans.. I think the dimensions of the hab platform are incorrect. The written rules have the dimensions of level 1 as 10'8"x 3' deep NOT including the ramp... The figure in the rules was changed today to match the text.

Mark Tarlton
Mark Tarlton6:51 PM

The rules document was updated today. Changes include a correction to the hab platform dimensions. This affects climbing designs

Enrique Chee
Enrique Chee7:14 PM

@Peter Hall @Harper Nalley rule changes ?

Justice James
Justice James7:37 PM

Here is the link to the rules PDF update. https://firstfrc.blob.core.windows.net/frc2019/Manual/TeamUpdates/TeamUpdate01.pdf

• The cargo ship / cargo ship hatch length and width were updated
• The Level 1 platform length and width were changed (this was an inconsistency pointed out on Chief Delphi)
• The depot (on either side of the climbing platform) length and width were updated
• The width of the loading zone was updated
• No precompressed air is allowed - `Throughout an event, compressed air on the robot must be provided by its one onboard compressor only.`
• Robot budget increased by $500 - keep in mind the budget was completely redone this year
• Several less important rules clarifications

Enrique Chee
Enrique Chee8:05 PM

@Justice James thanks

Lane Johnson
Lane Johnson9:29 PM

:spartronics: Good to take into thought, will definitely read :spartronics:

Paul Vibrans
Paul Vibrans9:42 PM

Easier than programming mecanum wheels and the same as programming a high speed elevator with a half arm on top.

2019-01-09
Chris Rininger
Chris Rininger8:03 AM

I am always looking at resources this part of the season, and I found these things that may help the three groups:
- For the team proposing the ramp, here's a Chief Delphi thread on that topic: https://www.chiefdelphi.com/t/is-it-possible-to-create-a-robot-to-work-as-a-ramp-like-this/339115/19
- For teams looking at cargo, here's a video showing team 254's intake in 2016: https://www.youtube.com/watch?v=tYHV3NP2UFs
- Speaking of intakes, here's an example of a single top roller ball intake with mecanum wheels on the sides for centering: https://www.youtube.com/watch?v=CMX4ynSQsyI --> My opinion: this is so simple yet effective, it is worth a taking a look. Here is the team’s tech documentation from that year as well, including close-ups of the intake: http://frc971.org/files/2016-TechnicalDocumentation-971.pdf

Chris Rininger
Chris Rininger8:30 AM

Picture of Team 971's intake from 2016.

John Sachs
John Sachs2:10 PM

Here's an example of a commercial stair climbing hand truck: https://www.youtube.com/watch?v=VRW-VLS-NOI or search for Escalera StairCat Hand Truck

John Sachs
John Sachs2:17 PM

You will find several variations of this by different companies; lots of good ideas!

Riyadth Al-Kazily
Riyadth Al-Kazily2:24 PM

Also note that some guy named Dean Kamen invented a stair climbing wheelchair: https://www.verywellhealth.com/stair-climbing-wheelchair-ibot-mobility-system-187962

John Sachs
John Sachs2:28 PM

Here's another climbing example that we might draw ideas from (a tail?!): www.amazon.com/Mattel-Terra-Climber-Control-Vehicle/dp/B01E7PGB8I

2019-01-10
Grant
Grant6:44 AM

Another good area to look at is stair cleaning robots. They typically have the same issue that we are running into, small wheels and an inflexible body

Chris Rininger
Chris Rininger6:51 AM

Interesting mechanism: reverse double 4 bar: https://youtu.be/CSvqpYRSb0k I think Chill Out did something similar last year & they said this is what they’ll do this year

Chris Rininger
Chris Rininger8:26 AM

Snow Problem ri3d final post. They did a low bot from reading their strategy paper (which is well done), so these materials could be quite valuable to review since the team is seriously considering going low. https://www.chiefdelphi.com/t/ri3d-snow-problem-2019/336114

Lane Johnson
Lane Johnson8:54 AM

@Chris Rininger that is a nice mechanism, my only complaint would be how flimsy/bouncy it is, however the cargo and hatch panels don't weigh a whole lot

Paul Vibrans
Paul Vibrans12:04 PM

The meshing gears at each end are an alternative to half the links in a scissor lift. The same number of bars in a different configuration, without the gears, would be a scissor and would not be as bouncy vertically.

Chris Rininger
Chris Rininger5:06 PM

Another way to do a centering ball intake: https://youtu.be/7EcA0DoLuc

Justice James
Justice James5:57 PM

Snow Problem's Ri3D video shows off a climber design unlike any other I've seen on Chief Delphi.
https://www.youtube.com/watch?v=qVEZoTRgkk

Their technical walkthrough (really well written up) has more details about the system.
https://drive.google.com/file/d/1Wl-wGhZO9JnNiRWyt73Sbki8ev0yqPRI/view?usp=sharing

Paul Vibrans
Paul Vibrans7:39 PM

Paul Vibrans
Paul Vibrans7:48 PM

I think we should look at suction cups and a simple vacuum system for gripping hatches instead of velcro or an expanding device that grabs the bore. Check out <https://vacmotion.com/Products/SuctionCups.aspx?SubCategory=Flat>. The model I would look at first is V-ZPT50US-G18F.

Chris Rininger
Chris Rininger7:50 PM

whatever is fastest and still reliable is what we should do - probably good to test some alternatives - cycle time is king

Chris Rininger
Chris Rininger7:50 PM

I like the look of the suction cups BTW :slightlysmilingface:

Chris Rininger
Chris Rininger8:02 PM

What an interesting and useful project! Thank you Paul. Given the results, what are examples of FRC robot applications (& what should we not do :))?

Darwin Clark
Darwin Clark8:33 PM

Good question for @Harrison or @Peter Hall, but I think suction cups might be illegal in rules.

Peter Hall
Peter Hall8:34 PM

Just so you guys know. Its Harrison and I that are the rule masters.

Justice James
Justice James8:37 PM

Rule master and rule goblin

Declan Freeman-Gleason
Declan Freeman-Gleason8:37 PM

Do you mean suction cups, or vaccums @Darwin Clark?

Peter Hall
Peter Hall8:38 PM

There is not a specific rule segment about suction cups or vacuums . It seems like they would be a legal option.

Justice James
Justice James8:42 PM

Through R84, vacuums are not considered pneumatics - does that change anything?

Chris Rininger
Chris Rininger8:42 PM

@Paul Vibrans, I assume your saying attach a pump to those, and suction on/off functionally, right? Seems like something fine to try - not sure how fast they would be shipped. As unsexy as velcro is, I think a solution that maximizes velcro contact surface area and has a reliable piston eject might be simpler and faster... need to test options.

John Sachs
John Sachs8:51 PM

Check out Q23 in the Q&A: "As per the Blue Box under R84, vacuum pumps are not considered a pneumatic item and are not disallowed or regulated per se. However, pay special attention to R34 as the motor within the vacuum pump is very likely not one of the allowed motors."

John Sachs
John Sachs8:53 PM

so unless we build our own vacuum pump, might be a no-go.

Chris Rininger
Chris Rininger9:09 PM

I've heard people buy pump then replace motor with legal one

Harrison
Harrison9:12 PM

I think a suction cup is a great idea. Even then, a suction pump sticks onto the hatch panel by creating a low pressure on the inside, were no air can escape. Wouldn’t the hole through the center of the hatch panel be a problem. So we would have to be fairly precise if we wanted to use a vacuum/suction cup. Or just keep the vacuum going on during the entire match and even then we still have to be fairly accurate.

I feel this idea would be good for a low bot if the cargo and hatch Panel were two separate mechanisms

Riyadth Al-Kazily
Riyadth Al-Kazily9:20 PM

The hatch-end of the suction device doesn't have to be a traditional "cup" shape. It is possible to make one that is "donut" shaped so that it can account for the hole in the hatch. As long as there is enough surface area of hatch such that the vacuum level overcomes the weight of the hatch, then it should work.

Harrison
Harrison9:23 PM

Oh I didn’t know that

2019-01-11
Binnur Alkazily
Binnur Alkazily9:53 AM

@Paul Vibrans I am curious as to ‘why’ suction cups/vacuum system over velcro. What pro/con discussion I missed on this?

Andrew Peterson
Andrew Peterson10:45 AM

I will not be able to make it to the meeting today until about 5:30

Declan Freeman-Gleason
Declan Freeman-Gleason10:47 AM

I would love to hear the pros and cons too. The only reason I've been told not to do velcro is because it might wear out, but I think if the velcro wears out then FIRST will need to fix it (because the panels won't even be able to attach to the field). The pro of velcro is simplicty of course.

Justice James
Justice James11:50 AM

As I understand it, the main pro is that one suction system can work with both balls and panels.

Riyadth Al-Kazily
Riyadth Al-Kazily11:58 AM

I challenge that assumption, in that the suction "cup" that is good at picking up balls will be a different shape than one to pick up disks with a hole in the middle of them.

Justice James
Justice James12:06 PM

https://www.chiefdelphi.com/t/would-a-ball-vac-be-a-plausible-idea-for-moving-cargo-around/336430/12
At the bottom of this thread, there's ideas for a unified suction system. I think that two separate systems would be less complicated than suction.

Binnur Alkazily
Binnur Alkazily12:37 PM

I like to see us evaluate the intake from the efficiency and effectiveness of acquiring game pieces (I watched too many games where we played cat & mouse…)
As an example, if we follow that logic, seems like one solution will require higher level of precision over another for efficient pickups

Paul Vibrans
Paul Vibrans12:43 PM

I am amazed at the interest generated by suction cups but I can't tell how serious people are about the concept.
I do not recommend suction cups for cargo because the surface is too rough to get a reliable seal.
I propose suction cups only for hatches, which are not mobile in either of their possible pickup orientations.
Multiple cups are desirable because of the hole in the middle of the hatch and the velcro on the side. I think I would start with four of the model I recommended. They are silicone rubber that, in my experience, has a high coefficient of friction that will not let the hatch drop when it is raised into position. They are 53mm diameter so will develop about 20 pounds of normal force with an internal pressure of a half atmosphere for each cup. Each cup should have its own vacuum source so leakage into one cup will not compromise the performance of the others. The vacuum source should be as close to the cups as possible and connecting tubing should be short.

Binnur Alkazily
Binnur Alkazily12:53 PM

:slightlysmilingface: I can see the implementation idea for multiple cups, but still don't see how it could help w/ efficient pickups. Velcro type solution seems simple mechanically (I know, talking as a programmer :smiley:) -- pick up can extend beyond the parameter of the hatch w/o requiring much precision. How much do we need to work within the parameter of the hatch for effective suction cup implementation?

Paul Vibrans
Paul Vibrans12:53 PM

I recommend using a dedicated pneumatic cylinder for each cup as a vacuum pump with a single pneumatic cylinder operated off the air system to stroke all of the pumps simultaneously. One solenoid valve would operate all pumps. I would place limit switches behind the suction cups that would close when the cups are compressed. The implement operator could see the status of all of the cups and decide whether to activate the solenoid valve to grab the hatch. Grabbing could be automatic if 2 of 4 switches indicate contact.
Each vacuum line would be connected to solenoid valve controlled air source through a spring loaded check valve having a cracking pressure of at least 20 psi. Air at greater than 20 psi will go through the check valve to release the suction cup reliably without having to force it off the hatch.

Mark Tarlton
Mark Tarlton12:54 PM

The advantage of the suction cups is that the suction would be much stronger than velcro and the release is easily controlled.

Mark Tarlton
Mark Tarlton12:59 PM

The other thing to think about is that many suction cup applications don't use any vacuum pump at all. The vac is formed when pressed on. The valve is only used to release the suction.

Paul Vibrans
Paul Vibrans1:02 PM

Velcro is not reliable so there needs to be some other way of securing a hatch for the potentially violent trip to the rocket. If the hatch is on the floor, a gripper for the inside or a grabber for the outside needs a way to get under the hatch, a difficult task from what I have observed. The hatches have a 6" wide ring that is smooth enough for suction cup attachment. The cups are 2" in diameter so the position accuracy required is +/- 2" to get all four attached. You really only need to get one attached to lift a hatch, but it will not be rotationally stable when carried.

Mark Tarlton
Mark Tarlton1:06 PM

@Paul Vibrans -- if we go with 4 cups, what are the chances we could go without the pump and instead rely on mechanical pressure to engage? if each cup has its own release valve, then there may be enough redundancy to cover partial engagements

Mark Tarlton
Mark Tarlton1:16 PM

For example: https://www.amazon.com/BabiQ-Puller-Suction-Handle-Remover/dp/B07GJG1XSJ/ref=sr120 It seems like we could do something similar using the cups that Paul suggested. The size is similar.

Justice James
Justice James1:29 PM

I have not seen anything suggesting that Velcro is unreliable.

Chris Rininger
Chris Rininger1:40 PM

Stumbled upon this paper that includes robotic arm suction cup tooling searching for something else. Could be helpful: https://ready-robotics.com/resources/end-of-arm-tooling-the-right-tool-for-the-job/

Chris Rininger
Chris Rininger1:44 PM

Btw, on reliability, I will say again testing is needed. Both speed and reliability of the overall solution are needed.

Chris Rininger
Chris Rininger1:48 PM

Even with suction cups the "flick forward" of an ejection piston may have better results than simply turning off suction cups. Would there be enough pressure to thrust the hatch panel forward? That would make placement positioning more forgiving, as we saw with the piston ejection of the velco-held panels on RI3D robots.

Chris Rininger
Chris Rininger2:04 PM

Rule change: robots can eject hatch panels up to 3 feet instead of 2 now. Fastest cycling robots will use this rather than a dock/detach approach. Also, “aggressive” hook Velcro (like the grip locking stuff) that damages the loop Velcro on the panels is disallowed... my read is they expect (not overly aggressive) Velcro + piston ejection to be commonly used. Here are the rules updates: https://firstfrc.blob.core.windows.net/frc2019/Manual/TeamUpdates/TeamUpdate02.pdf

Justice James
Justice James2:06 PM

"A robot may not be designed to shoot hatch panels more than three feet." If our robot has the capability to do this, will it pass inspection?

Chris Rininger
Chris Rininger2:24 PM

Good catch - sort of poorly worded. Inspectors will be looking for robots that obviously could shoot more than 3 feet (e.g. they use longer-throw pistons). I suspect they want robots to be able to flick panels 6 to 12 inches, but doing so might result in a missed flick (accidental eject button press enroute to target or whatever) traveling further than 2 feet laterally as it heads to the ground, so they bumped the number up to 3 feet.

Mark Tarlton
Mark Tarlton2:52 PM

@Justice James with regards to reliability, the two biggest areas of concern are pulling hatch panels through the bristles at the loading bay and ability to survive bumps or collisions when in-transit or when placing.

Mark Tarlton
Mark Tarlton3:00 PM

@Chris Rininger @Paul Vibrans Regarding ejecting panels, perhaps we can use suction to hold panels and then use air pressure to eject panels towards the target. The cups that Paul suggested could be used that way if we plumbed appropriately. I think the issue would be how quickly we could build up pressure in the cups. Another idea is a hybrid approach with velcro surrounding the cups to provide resistance against the ejection pulse. I think a prototype to explore the concerns and design options would be worth doing.

Riyadth Al-Kazily
Riyadth Al-Kazily3:05 PM

Custom pneumatic systems are not permitted. All parts must be off the shelf and rated for the pressures we use. I do not believe we could fabricate an ejection mechanism other than to use normal cylinders to push the hatch off. (ie, I don't think venting from a solenoid to a suction cup would be legit.)

Justice James
Justice James3:06 PM

@Mark Tarlton All of our tests with Velcro have shown that robots bumping into us will not make us drop it, and in all Ri3D videos I have seen the Velcro has more than enough grip to pull through the brushes reliably (provided our intake is angled properly).

I'm pretty concerned with adding something this complex, with almost no benefits.

Mark Tarlton
Mark Tarlton3:24 PM

@Justice James the issue of complexity depends on how you look at it -- as either a mechanism in isolation or the total robot solution. Paul is suggesting a single manipulator that's able to grab both cargo and hatch panels. The Ri3D examples I've looked at using velcro and pneumatic ejectors were panel-only solutions or panel solutions attached to the bottom of the cargo grabber. Those solutions have a lot of mass (motors and pistons) at the end of an arm. Increasing mass at the end of an arm increases torque at the arm base which in turn, affects robot stability and arm placement accuracy. As much as I like the ejecting capability of 3 pneumatic cylinders at the end of the arm, I would want to look at the total package before committing to a particular design direction so that all the costs, benefits and trade-offs can be considered together. At this point, I don't have a strong opinion as to which way we should go since we're still at the stage of evaluating design concepts. I'm happiest when I have good solid alternatives to choose from.

Mark Tarlton
Mark Tarlton3:33 PM

@Riyadth Al-Kazily -- I read the pneumatic rules again and <sigh> I think you're right. :persevere: Too bad, I was so looking forward to shooting hatches.

Chris Rininger
Chris Rininger4:12 PM

As already stated, let's be methodical. Identify alternatives, gather materials & make needed prototype parts, construct prototypes, test. On the other hand, let's also use what RI3D and other resource can teach us. We saw several velcro + piston ejectors already - enough that we have a feel for that type of solution, so maybe we should build the suction cup prototype and see how it compares. I do agree, some of the velcro + piston solutions were quite simple looking and effective.

2019-01-12
Chris Rininger
Chris Rininger10:17 AM

A few "Single Arm Bots" worth taking a look at:
Team 27 in 2011: https://www.teamrush27.net/history/2011-logo-motion
Team 694 in 2008: https://stuypulse.com/downloads/teamdocs/magazines/08mag.pdf
Team 2590 in 2014: http://frc2590.org/robots/bellerophon/
Team 5803 in 2018: apexfrc.com/level-red.html
Team 4613 in 2018: https://www.team4613.org/2018 (they also had a single big air tank)

Chris Rininger
Chris Rininger10:25 AM

Since prototyping is coming up, sharing...
1. Youtube FRC prototyping playlist (bunch of fun short videos at the beginning): https://www.youtube.com/playlist?list=PLsiEJAZgdF8LPWDAYBeQJ-EvkUpK295ra
2. FRC prototyping "how to" information + a bunch of pictures of intakes: https://drive.google.com/open?id=1JMOfwYPn0NeAqUxHljT5pBgLGqhw1lxW

Chris Rininger
Chris Rininger4:50 PM

118’s Everybot is out. Like last year, it is a great example of a robot that can make a considerable positive impact for its alliances, while being a relatively simple and inexpensive design. Scroll down a bit for the reveal video: https://www.chiefdelphi.com/t/the-robonauts-118-2019-everybot/337838/8 Also, tomorrow there will be match play with I think 4 simple robot designs including this one. Link to info (no time stated yet unfortunately, though FUN may have it): https://www.chiefdelphi.com/t/houston-week-6-mcc-event-this-sunday/338595

Riyadth Al-Kazily
Riyadth Al-Kazily5:54 PM

That's a sweet robot! I never knew about the Everybot -- what a great idea to enable new teams to compete and learn!

Paul Vibrans
Paul Vibrans7:06 PM

It can't pick up balls from the loading station but all we need to add to meet our requirements is the level 3 climber. Get the drawings and cut list.

Riyadth Al-Kazily
Riyadth Al-Kazily7:07 PM

I also note that it can't put hatch panels on the rocket at any level, due to the lack of bumper overhangs. But yes, analyze it and borrow all the ideas we can.

Paul Vibrans
Paul Vibrans7:21 PM

Engineering those changes could be quite easy compared to starting from scratch on a whole robot design.

Chris Rininger
Chris Rininger7:55 PM

One stated requirement is... Intake on one side and place on the other to reduce cycle time by eliminating turn around time from each cycle. Question for whomever cares to discuss: Is it better to be able to intake a given game piece on just one side and place on just the other side? Or is it better to be able to intake on either side and place on either side (reminds me of a ferry :))?

I suspect some people have been thinking the latter, but after thinking about controls, I think the "either side" approach doesn't buy much of anything as far as reduced cycle times, and the controls will probably be considerably more complex because the two sides would need to be managed. (This kind of thing is why I was hoping for mech controls mock-ups with the robot concepts.) Maybe someone has a clever way to do simple controls for "either side"? What do you all think?

Declan Freeman-Gleason
Declan Freeman-Gleason9:16 PM

I think you need one button to switch sides, and one button for toggling each intake type.

The reason (I think) the rough design ended up multidirectional was because you need to move the hatch panel from one side to another, and it seemed like a flipper arm was the best way to do that, and once you’re doing that you might as well attach the cargo intake to it.

Justice James
Justice James9:22 PM

@Chris Rininger Week -6 matches start at noon our time tomorrow.

Paul Vibrans
Paul Vibrans10:17 PM

Double ended ferries are a good analog. There is a mental issue that the ferry captains deal with by going to the pilot house at the other end. That can't happen with our robot. Apparent control reversal when the robot returns is always a problem. One solution I have thought of is having a modified joy stick that has a crank-like handle on the top that points in the absolute direction that the front of the robot points with deflection of the joystick stalk representing speed in the direction that the crank handle points. Deflecting the stalk in the direction of the crank would make the robot go frontward. Deflecting the stalk opposite the direction of the crank handle would make the robot go backward. Driving would be done by holding the end of the crank handle and "leading the robot by the nose." Letting go would center the stick and stop the robot. Rotating the crank without deflecting the stalk would rotate the robot in place. This scheme is not suitable for Mecanum wheels where there are two axes of linear motion plus rotation.

Mark Tarlton
Mark Tarlton10:30 PM

I think that reversing direction is easily done in software. For example, flipping direction may be as simple as having a "direction" variable that's either 1 or -1. You multiply Joystick X and Y values by direction. Flipping direction is done my flipping the sign of the direction variable . < This is where the programming team jumps in and says 'yeah, but....' >

Paul Vibrans
Paul Vibrans10:31 PM

If we use a modified version of 118's Everybot, there is no need to prototype anything because 118 has. We can shorten our construction period by one week.

Declan Freeman-Gleason
Declan Freeman-Gleason10:33 PM

We actually had direction switching as Mark describes on HELIOS.

Chris Rininger
Chris Rininger10:35 PM

There are going to be other such robots on display tomorrow, including this one by team 3847: http://blog.spectrum3847.org/2019/01/2019-day-6-spectrum-mcc.html

Paul Vibrans
Paul Vibrans10:49 PM

The 3847 robot requires much more engineering on the basic robot than the 118 Everybot. In theory you get the second level of the rocket for that, but you don't get the top level. That engineering and the prototyping that may go with it represents 1.5 weeks. Is it worth it?

Chris Rininger
Chris Rininger11:10 PM

I mean, as of now, decision is center arm pivoting on an elbow, with a manipulator on a wrist. Arm may be on a post. Acquire game pieces on one side & deposit on the other. And climb to L3. That's the decision that was made, and until the students decide to do something else, I assume that's the plan. So I've been trying to look for examples and resources that can help get to a design for that. I shared the Everybot because it is a cool thing in FIRST that hotshot teams do this for rookie and under-resourced teams, and also I think there might be ideas to borrow.

Chris Rininger
Chris Rininger11:33 PM

RI3D Murray State - seems closer to our arm idea (actually it's a 4 bar, right?), but only manipulates on one side because it's a tall bot. https://www.youtube.com/watch?v=GZXYIXbKnpM

2019-01-13
Paul Vibrans
Paul Vibrans6:30 AM

I am not sure what you mean by center arm pivot on a post, but if it is what I think it means, we won't save any engineering time at all.

Chris Rininger
Chris Rininger8:59 AM

Leadership decided, at the very least, on a lowbot strategy, and it was a strong majority. We need to get behind them.

The work of the strategy / scoring analysis group suggests the strategy is valid. Recap:
- There are 40 game pieces to score, more that most alliances will come close to scoring because that would require 10-second-cycles from all robots all match.
- The majority of the scoring locations are low, and there is no point advantage for high scoring locations vs. low scoring locations like in past years (other than the RP, and our L3 climb is a mitigation to that). This is key.
- In eliminations, "building a rocket" involves no bonus. Those scoring locations are worth the same as low scoring locations. If low locations are faster than high, low will be done before high.
- Add it all up, and the best lowbots (optimized for low tasks) will be picked for eliminations alliances at ALL levels, all the way up to Einsteins. The game is clearly designed for this to be the case, and I applaud the game designers because their game design creates an opportunity for non-hotshot teams to make it to a high level.
- I will state an assumption, in fact, that every elims alliance that can find a strong lowbot will pick one. If that is true, there are roughly 30% of elims alliance slots available to lowbots. Surveys indicate only 20% of teams are even going for the lowbot strategy. There are slots available for the taking.
- If you put it all together, building the best lowbot, optimized for those low tasks and (if we succeed) faster at those tasks than the majority of high robots, then we give ourselves the best chance to make it into elims at District Champs in Tacoma, to make it to Worlds, and to get picked at Worlds. I've looked at this over and over, and I agree with the student that our opportunity is better with this strategy than it is trying to be a high robot and competing for those slots with Shockwave, Bear Metal, Mean Machine, Error Code Xero, Circuit Breakers, Jack-in-the-Bot, IRS, etc. Those teams, who can all reuse and further refine their lift solutions from last year, are very likely going to take the high robot slots on elims alliances.

Of course, someone can disagree with all that I just said. If so, I would like to see the strategy and scoring analysis to back it up.

Paul Vibrans
Paul Vibrans9:35 AM

I don't disagree. I don't consider a robot that has the adjustment capability to reach the mid level of the rocket to be a lowbot. Once you add the articulating arm and the controls associated with it, you are more than half way to a rocket bot and you might as well go all the way to the highest level.

My concept design for a rocket bot used the arm for climbing to the 3rd level. My concept for adapting a 118 Everybot for 3rd level climbing uses the same jacks as my rocket bot concept plus some extending arms to substitute for the jointed arm that is no longer there.

To sum up, go low or go high, there is no in between. Not building a rocket bot means fewer opportunities to fail but fewer opportunities to learn. Building an enhanced 118 Everybot means even fewer opportunities to learn mechanical skills (and programming skills) but much greater assurance of finishing without extreme time pressure.

Chris Rininger
Chris Rininger10:01 AM

I’m not supporting or rejecting the Everybot path right now, but if the students decided to do something like Everybot + L3 climb, then are there not opportunities to improve/customize it that represent learning opportunities? Or really experimenting with intake options to get ours to be as fast as possible. Seems to me there will be plenty of opportunities to fail and learn whatever path we take. For example, there will be no limit to opportunities to reduce cycle times via sensors & programming, no matter what. Fewer tasks means more time to focus on and optimize each task.

Chris Rininger
Chris Rininger12:19 PM

Redoing this because I left the cargo ship placement target off the illustration. I created a draft of a document that holds key input information to a lowbot design with a simple arm + manipulator on wrist. There are other things that clearly could be added; it's a start. Here's a link: https://docs.google.com/document/d/10v8Ka60r9jYx90i6ICOdxpVIYmVNJunue6Je9cCkCBk/edit?usp=sharing Included in that is this pictured I've copied that shows the sizes and heights of the game piece acquisition and placement targets.

Chris Rininger
Chris Rininger9:49 PM

If you want an example of what "touch it own it intake" looks like, please watch the video of 254's intake in 2016 in my original post here. Since the balls that year were similar to this year in size, in my opinion we will need an intake mechanism that A) extends sufficiently outside our frame perimeter, B) is the width of our chassis for intake surface area, and c) centers balls very quickly into our open frame cargo channeller mechanism. Team 971 use mecanum wheels for centering as in the photo. It looks like 254 is also using small mecanum wheels for centering. If the Vex ones are too pricey or too big, we could find another source or even make our own.

Chris Rininger
Chris Rininger10:10 PM

There are lots of mecanum wheel designs on Thingiverse. Here's one from GrabCad community: https://grabcad.com/library/mecanum-wheels

Chris Rininger
Chris Rininger11:08 PM

Apparently the mecanum wheels on intakes thing began around 5 years ago. Here's a Chief Delphi thread, and I'll also share a quote from it. https://www.chiefdelphi.com/t/mecanum-wheel-intake-club/136572 "Once we switched to mecanums, the ball could enter the intake from literally any angle, including completely sideways (90+ degrees off center) and the ball would end up centered in the intake in less than a second. The mecanums had just as good of a grip as the Banebots wheels. We left two small traction wheels on in the center of the claw which actually provide the grip on the ball once properly seated, so we didn’t compromise our ability to hold the ball. All in all, it’s probably the single best upgrade we’ve made, at least in terms of effort to reward ratio." See also my post on Wednesday... In 2016, many of the very best teams used them, and I think we should seriously consider it. There is always talk about being like the Cheesy Poofs; well, in this small way we sort of could.

Chris Rininger
Chris Rininger11:14 PM

I recommend building our intake similar to 971's or 254's from 2016 (see my Wednesday post), with mecanums on the sides, grippy wheels in the center, chassis width roughly. And then we could put the hatch panel grabber on the same flip out extension. One module serving two purposes.

2019-01-14
Chris Rininger
Chris Rininger6:42 AM

Dana Batali
Dana Batali9:26 AM

Right! And yet there's more! We had a camera on each end and the DriverStation view automatically switched when the button was pushed. Also: the LED strips were blue when going one way and yellow when going the other!

Chris Rininger
Chris Rininger10:20 PM

Another simple low robot from University of Michigan RI3D: https://youtu.be/zlNXkQe0BQU. They decided to handle panels on one side and cargo on the other with a multi-level intake scoop / ejector. Overall, with a fast drivetrain, good driving, & some fairly minimal improvements (e.g. improve the panel handler), this could be a really good competitor.

Chris Rininger
Chris Rininger11:08 PM

Team 118 finally released ALL of their Everybot materials here: https://ccisdrobonauts.org/?p=everybot.

AND this "Behind the Glass" video is really worth watching to get a view of this game from the drive team perspective: https://www.youtube.com/watch?v=YeIbv-qbIHw&feature=youtu.be Actually, I'd say this is a must-watch video for everyone contemplating the robot.

2019-01-15
John Sachs
John Sachs10:42 AM

Put some small powered wheels on the bottom of that cargo intake and you could use it to help pull the robot up and onto the high step!

Terry Shields
Terry Shields9:16 PM

100% agree with Chris - Hey Team, as soon as you get Finals out of the way, WATCH THIS video. It’s a great way to see what a match looks like from the drivers perspective. Think you have a good idea how many game pieces we can successfully put away in 150 seconds? Watch this and see how time flies during a match.

Note John’s comment in the post above. After seeing this video, driving to Level 2 at end of match should not require a complicated system (we’ll save that for getting to level 3 :)

And early in the video they hint at Cargo balls getting in the way at the loading station. I’ve been saying that since Reveal Day. I hope someone can prove me wrong. Until then, beware!

2019-01-16
Paul Vibrans
Paul Vibrans12:13 PM

After working out a pretty good screw jack design for climbing straight up 19", I have concluded the amount of machining to execute the project requires outside help because of the sheer volume of repetitive parts. A pneumatic lift requires fewer parts that absolutely must be machined so I will be pursuing that solution.
The concept for the pneumatic jacks uses 4 cylinders with a 2:1 mechanical disadvantage to save space. Cylinders must be 1.75" bore by 10" stroke. Recommended source is American Air Cylinder and is their model 1750DNS-10 with a catalog price of $90.10 and a weight of 2.39 pounds. Each robot needs 4 of them.

Chris Rininger
Chris Rininger12:18 PM

Regarding repetitive parts for screw jack, would BARN CNC(s) help?

Enrique Chee
Enrique Chee1:00 PM

@Peter Hall ok, check if what we have matches the specs. that Paul has mentioned. If not please research vendor that Paul suggested or Bimba and lets put in an order. 8 of them will cost about $720 from American Air. Bimba ? cost ? get it sooner ?

Peter Hall
Peter Hall1:01 PM

Ok I'll check on the ones we have on Friday

Dana Batali
Dana Batali1:10 PM

fwiw: amazon has cylinders like this: https://www.amazon.com/Baomain-Pneumatic-Cylinder-SC-Bore/dp/B072VQ6SY2 (which don't match paul's specs exactly and might be overkill - 2kg each!)

Enrique Chee
Enrique Chee1:15 PM

@Dana Batali thanks

Enrique Chee
Enrique Chee1:17 PM

@Peter Hall please check with rules about pneumatic cylinders.

Riyadth Al-Kazily
Riyadth Al-Kazily1:18 PM

That one seems a little short, but this one is plenty long (~12" of stroke), while still being a little narrow (1.24" diameter): https://www.amazon.com/dp/B01F9YB578

Riyadth Al-Kazily
Riyadth Al-Kazily1:18 PM

And it's pretty cheap. If not needed for climbing, it may still be good to add to our inventory.

Enrique Chee
Enrique Chee1:19 PM

@Peter Hall we might need larger volume air tank reservoirs

Riyadth Al-Kazily
Riyadth Al-Kazily1:19 PM

I believe that all pneumatic components are fine as long as they are rated for the pressure we use, COTS (not custom), and not modified.

Riyadth Al-Kazily
Riyadth Al-Kazily1:21 PM

Note that these Baomain cylinders have metric threads, so we may need different fittings.

Dana Batali
Dana Batali1:23 PM

there are quite a few to choose from (some with unacceptable ship times)... Regarding length, Paul mentioned a 2x disadvantage scheme and called out the 10" stroke... I'm only acting like i understand what he's talking about :wink:

Peter Hall
Peter Hall1:23 PM

Rule R84 states that is allows "Pneumatic cylinders, pneumatic linear actuators, and rotary actuators," There don't seem to be any specific regulations on the types of cylinders. Also R84 allows "Pneumatic storage tanks (with the exception of White Clippard tanks P/N: AVT-PP-41)" The only tank that is against the rules would be the one specified there.

Riyadth Al-Kazily
Riyadth Al-Kazily1:36 PM

There are none with the same bore that Paul mentioned. Here is one that's way bigger: https://www.amazon.com/Baomain-Pneumatic-Cylinder-SC-Bore/dp/B072VQ6SY2

Dana Batali
Dana Batali1:37 PM

hey that's the one i originally linked! :robot_face:

Riyadth Al-Kazily
Riyadth Al-Kazily1:37 PM

The bore indicates how many square inches the cylinder is, which translates to how much force it can provide. With 60PSI from our pneumatic system, a 1 square inch cylinder will provide 60lbs of force. 2sq inch will provide 120lbs.

Riyadth Al-Kazily
Riyadth Al-Kazily1:37 PM

So it is! I thought that one was small...

Riyadth Al-Kazily
Riyadth Al-Kazily1:38 PM

(I read "2 1/2 inch stroke" the first time I read it... It's 2 1/2 inch bore :-)

Paul Vibrans
Paul Vibrans1:48 PM

Bimba does not make a 1.75" bore and for the comparable sizes and mountings I checked, American Cylinder Co. was much less expensive. Pressure rating for American Cylinder Co. products is 250 psi.

Paul Vibrans
Paul Vibrans2:02 PM

The guides for the lift legs are Knape and Vogt Manufacturing Co. model 8405B 20 side mount drawer glides with 90 pound rating and 20" slide distance plus 1" overtravel. The local distributor is Builders Hardware and Supply in Seattle, (206)281-3747. The model number corresponds to a bulk package of 20 of them and each robot will need 8. They can be bought in pairs using a model number of 8405P 20 in which case they come with a bunch of wood screws for mounting that we would not use and a blister pack that will foul the environment. I did not find an on-line source.

Riyadth Al-Kazily
Riyadth Al-Kazily2:49 PM

The 22" model is available on Amazon, but only two pair (4 slides) in stock: https://www.amazon.com/Knape-Vogt-8405P-10-10-Inch/dp/B008J0DBQI

Mark Tarlton
Mark Tarlton3:25 PM

When figuring travel length, we need 19" for the lift height, 2 or 3 inches for ground clearance when retracted, and maybe a bit more for reserve, right?

Enrique Chee
Enrique Chee3:34 PM

ok, students please put orders together this Friday so I can order on Friday or by Sun.

Paul Vibrans
Paul Vibrans4:35 PM

We do not want guides different from 20 inches long. The location of the wheels on the lifts will be pretty close to the robot wheels so the 1" clearance caused by the 20" stroke will provide sufficient approach and departure angles.
More length means more cylinder stroke and more money, plus more space in the robot for the moving parts to sweep through.

Chris Rininger
Chris Rininger5:20 PM

Here’s a discussion about tanks large & small. Teams that switched to large tanks (meaning they can fit them) seem to be happy overall. https://www.chiefdelphi.com/t/air-tanks/340921

John Sachs
John Sachs8:50 PM

Hatch Panel sub-team - please read Q106 in Q&A, and order the correct hook tape if you are going that route. "...some variants of hook tape are likely to "aggressively wear" the loop tape on the HATCH PANEL and are therefore prohibited." https://frc-qa.firstinspires.org/qa/106

2019-01-17
Chris Rininger
Chris Rininger8:04 AM

Was playing around with cargo geometry in 2D tonight. This is showing intake from floor and geometry for one form of delivery on the other side of the robot. John S. observed we might not gain much - I wonder if it would simplify things to put all hatch panel handling on the "front" and cargo handling on the "back"... seems like it would enable modularization and mid-season enhancement opportunities that might not exist with the cross-robot cargo approach like this. We could even have programmers write an automation for backing up slightly and doing a quick 180 degree turn (using IMU/encoders) after game piece pickup. Just ideas here folks.

2019-01-18
Lane Johnson
Lane Johnson5:00 PM

Screws and drill-bits have been sorted!

Chris Rininger
Chris Rininger9:19 PM

As we proceed with deeper prototyping, design, etc., I want to once again point everyone to this resource. It's one of the best things to come out in a while for understanding how things fit together in FRC. https://www.chiefdelphi.com/forums/showthread.php?threadid=167193

Chris Rininger
Chris Rininger9:31 PM

My mother is a pro seamstress/tailor & has this neat machine called a scan-n-cut that works a little like a CNC except it's for cutting fabric, iron-on decals, and the like. She used it to create the logo on the 2016 Stronghold standard. I was thinking, for bumpers, it might be cool to have 4915 in our official font (which is, I believe, "SF TransRobotics") rather than a generic font. Interested?

Jack Scheiderman
Jack Scheiderman10:00 PM

That sounds great. You may want to send that to Marketing.

2019-01-19
Jack Chapman
Jack Chapman1:17 PM

hey everyone, I created channel for each of the sub-groups that we have, could you please join the channel that you are working on?

Chris Rininger
Chris Rininger1:39 PM

I created a first draft of the steps required for each main cycle, including hatch panel cycle, cargo cycle, and L3 climb. Many of us believe that if we can stay very focused on cycles and optimizing the detailed steps that compose each cycle, it will help us be successful.

Feel free to adjust the steps that pertain to your mechanism or programming area. As far as ownership, the hatch team should own hatch cycle, intake/chute teams co-own the cargo cycle, and climb team owns climb. As the specifics of the robot become better known, the cycle steps will need to be refined to exactly align with how the robot functions and is programmed. Here's the link: https://docs.google.com/spreadsheets/d/1XJTmGgvRyhR7gzWnQ3PrXqUab3gRpSRD0auV0WZXI/edit?usp=sharing

Later, when time is right, we can begin timing complete cycles and also timing cycle steps as part of the optimization process.

Declan Freeman-Gleason
Declan Freeman-Gleason5:33 PM

Should we convene a small group of people to break those into sub-cycles, or do you think each (mechanics) mechanism group should do that? Also, when this more finished, we could display it prominately in the mechanics room to increase our focus on it (maybe put it on a whiteboard).

Chris Rininger
Chris Rininger5:46 PM

As you point out, there are multiple ways to proceed. I think a brief discussion with some group leads, mentors, and others could be useful.

2019-01-20
Chris Rininger
Chris Rininger6:37 PM

@Paul Vibrans Please share several pictures of your current design from different angles (top down & isometric in particular). Since the towers are mounted to the inside chassis walls, are the top surfaces of the outside of the chassis generally available to build onto / tie into?

Chris Rininger
Chris Rininger6:37 PM

Or is there something in F360 that would be better?

Darwin Clark
Darwin Clark7:02 PM

FYI: Here is the 2019 wiring/control map. This document is a direct copy + some cleaning of the 2018 version. https://docs.google.com/spreadsheets/d/1lR9CYn1wjTvvSBQCanzgtiyTt8GZbboRyQQt7uvdE/edit?usp=sharing

Riyadth Al-Kazily
Riyadth Al-Kazily7:36 PM

Do we have samples of the blue and red HDPE plastic that is used for the hab? I think it would be good to make sure any sensors we choose to assist in climbing work in a predictable manner. (ie, optical reflective distance sensors)

Jack Chapman
Jack Chapman7:37 PM

We ordered a sample of HDPE if the same finish as is on the hab, but it will be the wrong color

Chris Rininger
Chris Rininger10:49 PM

For those who have not seen it, here is an isometric render of the robot with the L3 climbing apparatus, created from the CAD Paul shared. https://1drv.ms/u/s!AikCDwtdoW5LxVHoHvUVQH9c1dKj

@Paul Vibrans I had been assuming the width of the intake was going to be able to be something like 28 inches (close to chassis width), but the location of the arm currently implies a width of around 16 inches. How wide can the intake be?

Chris Rininger
Chris Rininger11:16 PM

I saved an F360 project of the robot with climbing solution, and here is a public link so people can look at the robot using the phone and tablet apps as well as just in the browser. https://a360.co/2DnIYXE

It should be noted: the plan is to have an open-front chassis - just need to decide how wide.

2019-01-21
Micah C. Glasby
Micah C. Glasby9:40 AM

That would be cool. The only rules specifications can be found in <R29>. Basically, the numbers need to be 4 inches tall, have at least a 1/2 inch stroke width, be white, and be unambiguous. Doing our numbers in our font would be a really nice touch. We would just need 4 sets per robot. Thank you!

Austin Smith
Austin Smith12:47 PM

@Austin Smith has joined the channel

2019-01-23
Lane Johnson
Lane Johnson10:31 AM

Wow Looks Good!

Mark Tarlton
Mark Tarlton3:20 PM

#chuteteam Here's a web link to my current model of the robot with the Chute in place. https://a360.co/2DwWMz1 With luck, you'll be able to interact with the robot model even if you don't have Fusion 360 installed. This model shows a single intake arm and hatch panels at the front and rear.

Mark Tarlton
Mark Tarlton3:34 PM

Here's a link to some screenshots (there are a couple of old screen shots -- ignore them) https://photos.app.goo.gl/g6xNh5c9aS9v44eLA

Enrique Chee
Enrique Chee8:33 PM

What is next ? 3D print ?

Jack Scheiderman
Jack Scheiderman8:51 PM

Most likely so. We should test print them to make sure that they work with our treads (I cant remember what there called).
Edit: Belts

Paul Vibrans
Paul Vibrans9:55 PM

They are called belts

Jack Scheiderman
Jack Scheiderman9:56 PM

Thanks!

2019-01-24
Chris Rininger
Chris Rininger3:33 PM

Another robot to look at & maybe borrow ideas from. Looks like a winner: https://www.chiefdelphi.com/t/wcp-mcc-robot-2019-powered-by-vexpro/342967

2019-01-27
Chris Stanley
Chris Stanley11:56 PM

I am concerned about aluminum buildup on the grinding wheel. Here is what the good people at MIT say about it. http://web.mit.edu/machineshop/Grinder/aluminum.html. It is considered dangerous in industry. I recommend using a file or a grinder designed for use with aluminum. I was always told to only use materials that spark on that type of wheel.

2019-01-28
John Sachs
John Sachs6:17 AM

Thanks Chris; that's a good catch. Do you have a grinding wheel dresser that they mention? @Cruz Strom please remind the mechanics to not use the grinder for aluminum.

Chris Stanley
Chris Stanley7:43 AM

I have used a soldering iron to install ultrasonic brass inserts in the past works quite well.

Chris Stanley
Chris Stanley7:57 AM

I do not have one. BARN is likley to have one. Part # 4528A1 at McMaster-Carr $17.59

Cruz Strom
Cruz Strom8:13 AM

In the past, we have used a lathe cutter (in the process of sharpening it) to clean off the aluminum build up.

2019-01-30
Mark Tarlton
Mark Tarlton1:42 PM

2019-02-01
Chris Rininger
Chris Rininger9:08 PM

I had a sequencing idea tonight that I wanted to bounce off y'all. It seems to me the hatch panel handling system is the least intertwined with the other systems. On the other hand, the climber, cargo intake, and cargo chute are heavily integrated.

Would it be possible to expedite the hatch panel handling system and get it onto the robot for the programmers and drive team to use before the other systems? And then a lot of programming and driving practice could happen in that context. The other robot could be built out with the climber, cargo intake, and cargo chute as the priority. And then, after a lot of learning from programmers and drivers playing with it, a 2nd improved iteration of the hatch panel handling system could be put on the robot with the other systems on it.

What do you all think? I manage projects and think about sequencing of delivery across systems and teams a lot, and this sequencing I described above could be really, really helpful for making more progress sooner.

Chris Rininger
Chris Rininger9:40 PM

So if we did that, for a while we'd have the hatchbot (yes, they're really hatch panels, but 2 syllables sound better than 4 in this instance).

Declan Freeman-Gleason
Declan Freeman-Gleason10:17 PM

Keep in mind that @Peter Hall is planning to deliver an accurate testbed to programmers tomorrow, so we'll be alright.

Driving practice could use it, but we should be careful to watch out for other blockers, and ensure that Chris/Cruz will actually have time to use it.

I definitely like the refinement idea.

Chris Rininger
Chris Rininger10:25 PM

It seems like it's going to be quite a while before the cargo intake + chute + climber is all assembled & ready. I'm thinking doing the hatchbot may be a way to trailblaze on a number of fronts (driving practice, driving practice with camera, launching off L2 in Sandstorm, auto-in-tele for hatch panels, optimizing the hatch panel cycle overall...) a week & a half earlier than if we wait for a robot with all functions.

Declan Freeman-Gleason
Declan Freeman-Gleason10:49 PM

I think that makes a lot of sense… I’m curious to hear what some others think.

Mark Tarlton
Mark Tarlton11:19 PM

The eject pneumatics for hatches are mounted to the cargo chute so it's integrated with everything else.

Chris Rininger
Chris Rininger11:50 PM

We can easily stub that in my opinion. We need to find a way to work ahead on something while the big integrated thing gets done, and to me, this is it

2019-02-02
Lane Johnson
Lane Johnson8:26 AM

I think that would be a great idea even if our testbot only has one function, because this allows our drive team to get in a routine with one of the mechanisms, so when time is short they have less functions to stress about practicing with, however, by doing this, instead of channeling all our efforts into the actual robot, we would likely have half or so people working on the test bot and half on the comp bot, so that may not work as good as we think, besides the mechanics 🧰 Team is very behind so if we catch up and return onto schedule I think that would be a great idea @Chris Rininger @Mark Tarlton @Declan Freeman-Gleason

Chris Rininger
Chris Rininger8:34 AM

Problem is the one robot will be a bottleneck... One of the reasons the big all-systems integration is going to take time (maybe until bag day weekend) is that not everybody can work on the robot at once. This is a way to use our two robots. I think it really takes a couple adjustments: 1) hatch panel team creates two assemblies in parallel rather than in series. 2) someone (maybe the hatch panel team again) devises a quick and dirty mount that afixes one of the hatch panel assemblies to the 2nd robot in the same place as it will be on the main robot. Just starting drive practice a week earlier will be huge if we can pull it off, and the programmers will benefit too.

2019-02-07
Chris Rininger
Chris Rininger10:46 PM

Great resources from Spectrum. @Peter Hall the advanced pneumatics guide might be worth a look in particular https://www.chiefdelphi.com/t/spectrum-2019-resource-collection/334975

2019-02-09
Declan Freeman-Gleason
Declan Freeman-Gleason10:58 PM

I have a troubling graph from the robot 2 chassis (chassis 1)... The graphs look very similar to the issue we had on this same chassis before we replaced the gearbox, and it seems like it could be a gearbox failure (i.e. the drops are not physically impossible and their frequency is directly proportional to the velocity of the output shaft). This might mean that @Cruz Strom or @Jack Chapman have to deal with more drivetrain headaches (Perhaps we should be asking ourselves why this has happened again... Any thoughts from @Paul Vibrans or other mechanical mentors?).

On the other hand, there is no clearly discernible audible clicking like last time (visually, it's hard to say if the motors are slowing, which is no different from last time). This means that this might be an encoder issue. I'm going to go that route because we don't exactly have access to replacement gears or any of the grease (please chime in if this is not true or if we can do some further diagnostics without these materials). Does @Peter Hall and @Riyadth Al-Kazily think it's worth it to carefully disassemble the encoder to see if anything is wrong? It runs the risk of damaging the encoder, and I think that we don't have any more spare (if that's true then we should order more), but my productivity is significantly degraded by this behavior and I would love to resolve it.

The graphs are here: https://drive.google.com/drive/folders/1gwNMRk3jrFuKZvoUwyz3Dr3jnj9a0W1?usp=sharing

The graphs are labelled by date (see the file name, the one from 2-9-2019 is the one from today, the other is from when we had this problem before). In the graph from today the dropouts are more frequent (could be on a different gear then the other one), but the velocity also drops to 0. This is the most important insight, and the reason why I am cautiously optimistic that this is an encoder issue. Please ignore the acceleration graph.

Riyadth Al-Kazily
Riyadth Al-Kazily11:21 PM

I don't think it is wise to try and disassemble the encoder, and I don't know what we could find there that could explain this graph.
One thing that would help me would be if the graph could be re-plotted with the vertical axis being the output shaft velocity in RPM (ie, true encoder velocity), and the horizontal axis being time (ie, real time in seconds relative to the start of the acceleration). I am having some trouble understanding the units of the graph as it is.
I would mostly like to see how long a period of time these dropouts actually take, relative to the good measurements., and also the period between dropouts relative to revolutions per second of the output shaft. I am especially interested in knowing the second bit, to determine if the dropouts are happening once per rotation of the output shaft or not. If the time between dropouts is the same as the time for one output shaft rotation, then looking at the encoder might make sense. Otherwise, the source of the problem must be somewhere else. Knowing the frequency (in real time) relative to output shaft rotations should help us determine which stage of the gearbox (or belt system) is likely to be inducing the problem.

Declan Freeman-Gleason
Declan Freeman-Gleason11:36 PM

@Riyadth Al-Kazily The units of the velocity graph is rad/sec. I have added a graph where the X axis is time to the folder linked above (LeftforwardTime-Domain_Plots.png).

Declan Freeman-Gleason
Declan Freeman-Gleason11:54 PM

I will run things at a constant velocity and post a graph here in while, with velocity units in RPM.

2019-02-10
Riyadth Al-Kazily
Riyadth Al-Kazily12:17 AM

rad/sec of the output shaft? (ie, of the encoder?)

Declan Freeman-Gleason
Declan Freeman-Gleason12:17 AM

Yes, of the output shaft.

Riyadth Al-Kazily
Riyadth Al-Kazily12:24 AM

I would say then that the dropouts are indeed occurring at about the same rate as the output shaft rotation (ie, the time from one dropout to the next is approximately the same as the number of rotations per second. At about 6.2 radians per second (one rotation per second), the dropouts are about 1 second apart. And since the "duty-cycle" of the dropout seems to be in the 25% to 50% range, that would mean the output shaft would have had to nearly stop for at least 250ms at the low speed of 6.2 radians per second. That would be extremely noticeable if it were actually happening.
I now do suggest that we take apart and examine the encoder. This sort of looks like it could be a smudge or other dirt on the encoder disk itself, such that every time the dirt rotates past the sensor, the signal is lost. @Peter Hall Was care taken to keep the encoders as clean as possible during assembly?

Declan Freeman-Gleason
Declan Freeman-Gleason1:04 AM

Yup... That sounds about right. I've recorded at a constant velocity and it's pretty clear that the dropouts are synchronized with the full rotation of the output shaft, as you said.

https://docs.google.com/spreadsheets/d/1KEQhHRkAdnDLQB4FVSGSuF8BzenQFuFmHxnMljhjmI/edit#gid=1032315128

For 25% demand, dropouts appear to be ~0.6 seconds apart. The maximum speed at this demand is 100 RPM, and 60/100 = 0.6.

Riyadth Al-Kazily
Riyadth Al-Kazily10:34 AM

@Declan Freeman-Gleason Did the "bad encoder" always perform that way (ie, you noticed it immediately), or did it get bad over time? If always bad, then it would point more towards an assembly issue ("dirt" introduced during assembly). If it got worse over time, then maybe foreign objects (also "dirt"?) may be getting in to the encoder. This could be grease or something coming through the bearing from inside the gearbox, or material unrelated to the gearbox coming from somewhere else.

Declan Freeman-Gleason
Declan Freeman-Gleason10:46 AM

@Riyadth Al-Kazily I didn’t notice that there was a problem for a while (I don’t remember if I looked at the graphs at all because they weren’t important to what I was doing), so it’s possible that it just “appeared” when I started to run it on the ground and look at the graphs, but it’s also possible it’s been there for a while.

Declan Freeman-Gleason
Declan Freeman-Gleason12:28 PM

@Riyadth Al-Kazily @Peter Hall It looks like a wiring or mounting issue!

The yellow wire leading directly to the encoder looks like it's about ready to come out, when pressed in the issue mostly goes away. This doesn't really explain why the dropout is once per revolution.

The thing is that when the wire gets pushed in the entire encoder housing flexes and gets pushed in as well. This makes it seem like it could be a mounting thing.

Unfortunately I'm away from the robot right now, and I can't try only pushing the housing in or only pushing the wire in (to see which one is the problem), but that will be my next step when I come back.

A video that demonstrates this will be posted here soon.

Peter Hall
Peter Hall12:30 PM

@Declan Freeman-Gleason I'm glad that it is being figured out. I don't think that there is anything that i can do from home but if so let me know

Declan Freeman-Gleason
Declan Freeman-Gleason12:34 PM

@Peter Hall Let me know what you think of the video. I'm going to try taping the encoder down as securely as I can (the tape seems to have fallen off) and if that doesn't work then I might explore giving the wires more play (they have very little right now, and we might try to avoid that in the future).

Declan Freeman-Gleason
Declan Freeman-Gleason12:34 PM

https://drive.google.com/file/d/1rjFbnFpG2crNqBEoj-4H3Hxh8GZOIY-/view?usp=sharing (Video is still processing, unfortunately)

Declan Freeman-Gleason
Declan Freeman-Gleason12:46 PM

@Riyadth Al-Kazily @Peter Hall The above video is now available. Let me know if you see anything that I didn't.

Riyadth Al-Kazily
Riyadth Al-Kazily12:56 PM

Excellent debugging work! The loose/failing connection could easily be affected by output shaft rotation. No mechanical device is 100% perfect, and rotating machinery will always have some eccentricity. After all, our parts are not NASA quality (I'm looking at you, AndyMark). So a slightly non-round output shaft or offset bearing or oval gear could put more pressure on the circuit board (maybe even transmitted through the frame, resulting in flex of the sensor), and that could be enough to go from good signal to dropout.
The good news is that we can make the connection more robust. It may actually be a solder joint on the encoder board, and we can "re-wet" the solder to make it flow and eliminate cracks. It may also be the connector itself, probably on the wire side, and that is also easily replaced.
@Peter Hall do we have spare encoder boards in case we need to replace it altogether?

Peter Hall
Peter Hall2:00 PM

i think that we have one spare board

Riyadth Al-Kazily
Riyadth Al-Kazily4:49 PM

I'm thinking that we should have more than one spare on hand... Can we order some more?

Riyadth Al-Kazily
Riyadth Al-Kazily4:50 PM

(Also, is the "broken" one still available? I assume the board was fine on that one.)

Terry Shields
Terry Shields9:29 PM

Coming in late to this discussion... but I remember last year when we had encoder mounting issues. Problem #1: When mounting the encoder base to the gear assembly with the 2 screws the “centering tool” (that tiny silver tube) was not used or not used properly. That centering tool ensures the PCB board is centered perfectly around the shaft. Problem #2: could be that the optical sensor was touched with oily fingers or contaminated when placing the PCB onto the mounting base. Problem #3: the PCB was not seated fully down on the base. Last year that was was caused simply because one of the two mounting screws was not fully screwed in. The head of one screw was high enough to cause the PCB to be tilted ever so slightly inside the housing. A dead giveaway for this problem is the plastic cover, the last piece of the assembly, does not sit squarely on the base and you do not get that distinctive “click” that tells you the cover and base latch together. Problem #4: make sure that thin little Mylar disk on the hubdisk is seated properly on the shaft before you start pressing down with the supplied spacer tool. Problem #5: we’ve manhandled the PCB and partially broken/loosened a wiring connection.

Declan Freeman-Gleason
Declan Freeman-Gleason10:25 PM

Thanks for the thorough response Terry!

Does @Peter Hall if we used the centering tool (see number 1 in Terry’s?

Does the entire encoder housing “flexing” constitute one of these issues, or something else?

2019-02-11
Terry Shields
Terry Shields10:59 AM

If the entire encoder housing is rocking I say Problem #3 is the culprit and we red to ensure the base is completely screwed down with the 2 screws. And make sure the little silver “centering tool” tube is used when tightening those screws.
If just the encoder cover is rocking then the PCB board is not seated all the way in the base.

Declan Freeman-Gleason
Declan Freeman-Gleason8:33 PM

The encoder issue has been solved with some tape (the housing was moving), and even better the friction issue that has long plagued us has been fixed!

It turns out that moving the battery from the front crossbar to the back of the robot solved our problem! The battery is going to be on the back of the real robot, right?

Cruz Strom
Cruz Strom8:36 PM

Yes it will.

Declan Freeman-Gleason
Declan Freeman-Gleason8:36 PM

Great!

Paul Vibrans
Paul Vibrans9:21 PM

The center of gravity must be forward of the middle wheels (on the intake end) with the intake arms extended or the robot will tip backward when the last stalks retract during a climb. We may need ballast.

Dana Batali
Dana Batali9:28 PM

Is the theory that the weight caused some distortion/bending?

Chris Rininger
Chris Rininger10:41 PM

hmmm... Cargo intake + front stalks vs. rear stalks, hatch panel handler, and battery... The chute seems fairly balanced between front and back. Will the front or back of the robot win the COG battle? I hope the front wins!

Declan Freeman-Gleason
Declan Freeman-Gleason11:35 PM

Potentially? It seemed a little saggy looking to me (that’s why I moved the battery in the first place), but I’m not really that sure.

2019-02-12
Terry Shields
Terry Shields11:08 AM

Great work flushing out these problems Declan!

Mark Tarlton
Mark Tarlton6:53 PM

FYI #chuteteam: There is an interference problem between the Chute and the front crossbar behind the intake wheels. If the Chute's holding a large cargo ball when being raised from 30 to 45 degrees, the clips holding the top rail will collide with the cross bar. The image below is a side view showing the intersection point when the top rail is all the way up. We should test this case with the robot to verify. https://drive.google.com/open?id=14EOedv4CwOTIXUjAtWFqcWE4SyFzHck1

John Sachs
John Sachs8:00 PM

How much do we need to move the cross bar up by? We could fashion a couple of extension plates if needed.

Paul Vibrans
Paul Vibrans8:32 PM

The top rail also hits the shaft on the intake or so it would appear.

Chris Rininger
Chris Rininger8:54 PM

Could have 2 smaller rails at 10 and 2 o’clock maybe? There are carbon fiber golf club shafts in the robot room that are lightweight and could work.

Declan Freeman-Gleason
Declan Freeman-Gleason9:26 PM

By the way, barring a design change, this is going to be fixed by disallowing “arm up” during “chute up” in the code.

Kenneth Wiersema
Kenneth Wiersema10:29 PM

I did a weight analysis on the robot, including as much as I could, but there are still several parts unaccounted for, along with any electronics/pneumatics things that I missed. And the number that the spreadsheet produced was 129.5 pounds. Holes in some of the parts are not accounted for, but some are the raw volumes gotten from cad. The cylinder mass was estimated from an andymark cylinder of the same bore, but shorter length.

Everyone's welcome to check my work, but as this doesn't contain all of the parts, the true mass of the robot is above 125 pounds regardless. So we need to add lightening the robot as a priority over this last week. There still needs to be a final weighing of subsystems to really lock down the weight number, but I would put the robot at being at least 135 pounds or more. This will be discussed at the next mechanics meeting by leadership members and mentors.

https://docs.google.com/spreadsheets/d/1rMmZ0m3heth0xTNM24FdCtIbxjViec4sW-r4agZHl7I/edit#gid=0

Mark Tarlton
Mark Tarlton11:21 PM

I estimate less than an inch of room is needed to sneak under the bar.

Chris Rininger
Chris Rininger11:27 PM

Maybe shorter bar with Onyx extension curved down slightly from the line of the bar so it clears the intake?

Mark Tarlton
Mark Tarlton11:28 PM

Yes, as Declan said, the software needs to manage that conflict. The intake and chute can't both be up at the same time

Mark Tarlton
Mark Tarlton11:29 PM

Its ok when the chute's down.

2019-02-13
Mark Tarlton
Mark Tarlton9:08 AM

It's not the bar, it's the clips that attach it to the hoops. They have to move to account for different sizes balls. With large balls, they get pushed all the way up and hit the cross bar as they pass by.

2019-02-14
Chris Rininger
Chris Rininger9:06 PM

@Paul Vibrans how much weight might be saved switching to carbon fiber square tube like that on the climbing stalks... a pound or two maybe? We could probably find a local source

Paul Vibrans
Paul Vibrans9:31 PM

Since we would need to take the climber apart completely to replace the aluminum with carbon and once it was apart we could also consider drilling holes in the aluminum to save weight. Carbon tubes without lightening holes weighs the same as aluminum with lightening holes for the same thickness. Carbon requires the use of tungsten carbide tools for proper cutting and we have few if any of these. I am not sure if special procedures are required to contain carbon dust from fabrication.

Chris Rininger
Chris Rininger9:43 PM

The place that sells the lighter Omni wheels is located in Redmond... just 1/2 lb, saved but could go get some

Chris Rininger
Chris Rininger9:54 PM

For anyone looking at ways to lose weight (& avoid needing to do this weight loss thing in the future), I recommend these two in-depth discussions about the topic:
https://www.chiefdelphi.com/t/weight-saving-techniques/137407
https://www.chiefdelphi.com/t/weight-loss-strategies/127844
And here's a set of slides dedicated to the topic: https://www.chiefdelphi.com/t/paper-robot-weight-watchers/96338

Enrique Chee
Enrique Chee10:02 PM

I also have some other Omni wheels that are less mass ? Not sure of the diameter , may 3 inches . Remind me to show on Fri.

Enrique Chee
Enrique Chee10:05 PM

@Cruz Strom let's remove climbing system and drill cheese holes ! Plus anywhere else like chassis and battery holder . For that matter , build a smaller mass battery holder .

Enrique Chee
Enrique Chee10:09 PM

Weight saving :Use rivets instead of nuts/bolts . I noticed some large mass hex collar . Replace with smaller mass collars . There are 3 types of hex collars.

Chris Rininger
Chris Rininger10:33 PM

Here's a list of things gleaned from reading the weight loss discussions shared earlier. Can some of these be applied to your mechanism?
- Assign a certain amount of weight loss to each system (& in the future, give each system a weight budget). Share the love (& the pain).
- Attack dense materials first. Steel and copper first, since they're more dense than aluminum
- Trade nuts and bolts for pop rivets or even velcro for some things. One team said they saved 3 lbs this way one year.
- Use 1/16 and 1/20 inch thick aluminum tube and sheet above chassis level unless absolutely necessary. More than one person said their team almost never uses thicker material than 1/16 tube. I don't even think we have anything thinner than 1/10 do we? It seems like this is definitely something to look at for the future.
- Eliminate unneeded panels and parts of panels
- Redesign mechanisms to be simpler, lighter. Can a belt or wheel be cut? Can a smaller shaft (3/8 hex instead of 1/2) be used?
- Yes, lightening holes, but more than one person said they should be a last result and that they've seen catastrophic failure from excessive holes before. It is almost always better to switch from 1/8 to 1/16 tube (50% weight savings) rather than drill a bunch of holes in the 1/8 (very difficult to achieve the same weight savings and retention of strength). If lightening holes must be done, then remove or THOROUGHLY cover electronics and other critical elements that could be damaged by shavings
- Use the shortest bolts necessary - you only need a thread or two past the nut
- Thinner polycarb for panels: Team 33 uses 0.020" or 0.30" for panels. 1/16 is plenty tough for nearly any application according to the experts. Never a real need for 1/4".
- Apparantly Vex gears and gearboxes weight less than AndyMark in general - another one for the future
- Custom chassis using thinner sheet metal than the kitbot can weight a lot less - another for the future perhaps - would require summer/off-season commitment
- Get strength from geometry rather than material thickness
- Replace drivetrain gearbox side plates with lighter material (maybe Onyx?)
- Make wires just the right length - remove all excess (one team said they lost 7 lbs one year cleaning up a messy wiring job - I don't think we have that much to lose)
- Fiberglass/composites (more for future probably)
- Remove motors - or downsize
- Thinner walled pvc
- Use 10-32 instead of 1/4-20 wherever possible (& it is often possible in a lot of places - or better yet, pop rivets like said before)

Chris Rininger
Chris Rininger10:34 PM

Should be able to design & 3D print a light but strong battery holder

2019-02-15
Mark Tarlton
Mark Tarlton12:00 AM

Before we dive into the lightening exercise, I would like to test what we have now. Weight may not be the only problem we need to solve.

Chris Rininger
Chris Rininger1:44 PM

I noticed there are 500mm carbon fiber round tubes in many diameters on Amazon Prime - very light weight & strong - might substitute well for heavier things on robot.

Chris Rininger
Chris Rininger10:04 PM

One of the lightening opportunities was replacing nuts and bolts with pop rivets. Was this considered? I just studied up on rivets to learn a bit more about them, and it seems like a great option in a lot of places, and lighter weight at that.

Kenneth Wiersema
Kenneth Wiersema10:07 PM

Both Jack and I agree that rivets are a possible, but another last case scenario, the primary problem with them being is that they're annoying to take out, and would probably slow us down when it comes to fixing the robot during competitions. If there's something we're sure isn't going to change it's fine, but I want that flexibility built in, rather than having to deal with a more permeate solution down the line.

Chris Rininger
Chris Rininger10:08 PM

Hmm in the videos I watch they just drilled them out in seconds, which seems a lot faster than dealing with barely accessible bolts

Kenneth Wiersema
Kenneth Wiersema10:10 PM

Not in my experience, and there's about a 25% chance that we really get stuck on drilling one out. I'd like to explore other options before deciding on this in a hurry. Also, I don't think it would be worth our time to do so.

Chris Rininger
Chris Rininger10:12 PM

I’d like to see the hypothesis proven sometime that they’re slower, They seem faster to me, especially if the bolt is the least bit difficult to access.

Jack Chapman
Jack Chapman10:28 PM

We really should test it, but I remember it taking at a bare minimum 30 seconds per rivet, not including time to figure out which drill bit to grab

Mark Tarlton
Mark Tarlton11:09 PM

Where rivet removal goes bad is when the rivet spins in the hole so the drill bit isn't able to bite into the rivet. We then struggle to grab the rivet with vice grips and it gets ugly. As a compromise, we've used some self-tapping screws on the chute that don't require a nut or tapping -- they're only slightly heavier than a rivet.

Mark Tarlton
Mark Tarlton11:10 PM

-- we used rivets on the harvester last year and had those experiences.

Mark Tarlton
Mark Tarlton11:13 PM

Also access should be considered. there are places where you can get a stubby screwdriver or a wrench in, but not a rivet gun or drill.

Rivets do have a lower profile so there are places where they are superior.

2019-02-17
Chris Rininger
Chris Rininger8:47 AM

Inspiration from Robot Reveal Videos. Here are a few out so far, and some observations
--- 7033 Roosters (https://www.youtube.com/watch?v=d2ukBXVqjNQ). Single joint arm for Cargo (shooter) + active hatch panel mechanism. Quite simple design.
--- 4613 Barker Redbacks (https://www.youtube.com/watch?v=zDRk5KeEqkg&feature=youtu.be). Thinking about our weight challenge, their Cargo intake is inspiringly low weight (though I think ours will have an edge 1:1 actually). The climbing solution and suction cup-assisted buddy climb are also really creative and effective.
--- 6510 Pymble Pride (https://www.youtube.com/watch?v=oks73hwY0Eo&feature=youtu.be). They executed something similar to Paul's idea of one mechanism for Cargo and Hatch Panels quite well. Another creative climbing solution, including climb to L2 then L3.
--- 2576 Chilean Heart (https://www.youtube.com/watch?v=jKMKsJNpFfk). Elevator (as were 4613 & 6510). Well executed overall, including good use of lightweight tube.
--- 2883 F.R.E.D (https://www.youtube.com/watch?v=3sF5xEPK8qc) :slightlysmilingface:

2019-02-19
Enrique Chee
Enrique Chee11:56 PM

Sorry , Chris R. already posted 4613.

2019-02-21
Doña Keating
Doña Keating11:04 AM

Have we created reveal videos in the past?

Binnur Alkazily
Binnur Alkazily11:27 AM

Yes - should be on the YouTube channel- Atlas certainly comes to mind, but I think we had at least one another

Chris Rininger
Chris Rininger12:54 PM

Physics students, help me out. On the hatch channel we're grappling with a problem involving the front of the robot taking a full speed impact because the ground-level field element cutouts are deeper than our bumpers are thick. I decided to try to figure out how much force we're talking about. Here's what I came up with - does it look right?

Jack Chapman
Jack Chapman12:57 PM

It looks good

Chris Rininger
Chris Rininger7:05 PM

Next up: Figure out deflection distance during the period of deceleration to a stop. Here's what I came up with. If this is correct, then we probably will not be able to stop the robot with a within-the-weight-limit barrier mounted to the chassis. We're probably better off not having anything vulnerable within the first 2 or 3 inches of the frame perimeter (or there's an outside chance we could use a software solution).

Physics people, check my work & my conclusions please. Thanks.

Chris Rininger
Chris Rininger9:46 PM

Robowranglers (FRC 148) reveal. Close to the beginning of the video, notice the hand operated chasses they're using during prototyping/testing in order to have mechanisms interact with field elements and game pieces like a robot would. I really would like to see use develop this ability. Also, near the end, they show a bunch of climbing fails that should let us know we're in good company with our iterative refinement of our own climber. https://www.youtube.com/watch?v=Xsur2oiqmjk

Justice James
Justice James9:55 PM

That drivetrain's pretty cool! I just wonder how it will fare against defense...

Justice James
Justice James9:56 PM

Here's a blog post I found on it
https://johnvneun.com/blog/2019/1/3/x019-prototype

2019-02-22
Chris Rininger
Chris Rininger12:17 PM

OMG! FRC 2521 SERT created a robot that is a close relative to ours. Here's the reveal: https://youtu.be/5IBZdiyKaGY

Chris Rininger
Chris Rininger12:45 PM

Here's a youtube playlist of more robot reveals (over 300 and rising) than you probably have time to watch. https://www.youtube.com/playlist?list=PLocx3vY5mUKNP-v3Wm1v01kLMvQiWMLe

2019-02-23
Justice James
Justice James12:49 PM

This robot has a hatch panel grabber with a little hinge to help it line up.
https://www.youtube.com/watch?v=DJXDVtx8l6g

Chris Rininger
Chris Rininger1:29 PM

Wow Justice, nice find! @Mark Tarlton ^^^

2019-03-02
Mark Tarlton
Mark Tarlton12:05 PM

Today I Learned: With the MarkForged printer, you will NOT receive any "low filament" warnings if you do a "Quick Load" of filament when loading plastic. Instead, you need to do a "Meter Load" and then select either "Full Spool" or "Partial Spool" (which then requires you to weigh the spool).

So, my advice -- Don't use the "Quick Load" function when loading filament on the MarkForged printer.

2019-03-03
Chris Rininger
Chris Rininger10:52 AM

Remembering James S last year, the thing to do is 1) Align with Cruz on controls that make sense to him, 2) get Cruz plenty of time to practice with the controls to reduce likelihood of errors.

I wonder if we could just keep the CK button board for all the manual elemental controls... keep it consistent / as is, but not as the in-game control system. And then have a separate controller for the more refined controls Cruz will use in game (i.e. that execute sequences rather than individual functions). A simple digital-only handheld controller that would let Cruz keep his eyes on the field or camera feed might not be a bad option. People seem to like this one: https://www.amazon.com/Buffalo-iBuffalo-Classic-USB-Gamepad/dp/B002B9XB0E/ref=sr11?keywords=buffalo+game+controller&qid=1551638948&s=gateway&sr=8-1

Chris Rininger
Chris Rininger12:35 PM

One glaring risk to me is the risk of accidentally putting the cargo arm down into climb mode given the downlocks. I recommend moving that function to the very top right small button on the CK button board, and move the functions currently on 9 and 10 to 7 and 8. Or something like that. @Ronan Bennett @Cruz Strom agree?

Mark Tarlton
Mark Tarlton9:03 PM

All -- Here are my notes from today's time at CK high. Although most of the notes are about problems, there were successes as well, so don't get depressed.

The pneumatics system got tightened up this morning before we left and they behaved properly through out the day.

For the hatch handler, we tweaked the velcro/pneumatic system this morning. We were able to get and place hatches -- problems with the field elements prevented us from a real end to end demonstration but we were able to simulate the grab through the brushes and then eject the panel to the target. Eject seemed to work pretty well. However, the new attach points for the velcro got caught in the field element opening and then were ripped off. Modifications to the design will (hopefully) keep this from happening again. We need to refine the existing design but the changes seem minor.

#cargointake and #chuteteam
We were able to intake cargo but the depth sensor wasn't installed in the chute so they just passed through. This meant we were not able to really do end-to-end grab and place of cargo since the cargo just went in one end of the robot and out the other. The good news is that the chute is ejecting pretty well but there are several problems here:
(a) the depth sensor needs to be installed in the chute.
(b) the top bar needs further shortening at the back end
(c) the versablocks slid down the polycarb tubes resulting in loose belts. We need to prevent the sliding.
(d) the angle for ejecting to the cargo ship is still not right. The work around for this is for the #programming folks to change the 'cargo eject' function to drive about 6" away from the cargo ship before actually starting the ejection motors
(e) when the cargo doesn't make it into the cargo ship, it will often balance on the end of the cargo chute. It would be nice if the programmers could do a cycle that would run the chute in reverse to see if we can suck the ball back into the chute and try again.
(f) the hex bar used to mount the chute seem to be short and they came out once.
(g) we had problems with collars coming off. we need to find a way to do better.
(h) we may still need to add guides at the front of the intake to prevent cargo from coming in too early.

We were able to eject cargo into rocket. It's a real challenge for the driver to get the robot in the proper position -- this is true for all aspects of the game.

We broke several little roller arms on the Intake mechanam wheels by driving into the rocket.

#strategy -- It's really difficult to eject cargo into the forward oriented bays of the cargo ship. We need to make sure our alliance places hatch panels on those openings during standstorm to capture the pre-placed cargo.

#climbteam Climb doesn't work. The front legs were coming out ahead of the rear legs. We experimented with timing the front eject but had no success. The wheels seemed to drag across the plywood when we raised it up and tried to pull in. The intake arms didn't touch the hab top surface. We didn't try lowering the front legs because Cruz was concerned about damaging the intake motors.

#electronic-pneumatics -- we had numerous radio drop outs -- especially after 'enthusiastic' encounters with field elements. Also, the camera mount stalks kept sliding down so the drive team didn't get a consistent view of the field so alignment was even harder than it should be.

#programming -- when the cameras worked, I think they were effective. but they seemed flaky --

2019-03-04
Chris Rininger
Chris Rininger9:11 PM

@Cruz Strom @Ronan Bennett I've been reviewing the controls stuff tonight, and it seems to me we should minimize cycle times by using any automated sequences that work faster rather than the manual step-by-step approaches. Have the automated sequences been tested/tuned on the main robot yet? Or is that part of the plan for Wednesday? To me, hatch panel acquisition, hatch panel delivery, cargo delivery to cargo ship, and cargo delivery to the rocket should be single button press things that trigger horizontal alignment, positioning (e.g. back up a bit from cargo ship before shooting), configuration (e.g. raise/lower chute), and acquire/eject. The acceptable spacing dealing with both game pieces is tight, and if sensors & software can save time, we should make those primary buttons for Cruz (IMO). That said, if manual ends up being faster or if the automated sequences are unreliable, then let's do manual.

Declan Freeman-Gleason
Declan Freeman-Gleason10:12 PM

We tested some of the automated line-up today, and reliability didn't look great. This may have been because I changed lighting conditions (which should be a little more static at the competition). We have another strategy for lining up (that isn't one-shot), and we're going to try that as well on Wednesday.

2019-03-05
Chris Rininger
Chris Rininger2:35 PM

Reposting - somehow my original post was lost making an edit.

Sharing observations associated with team 1690 (Orbit).
- Here's a video of them placing 12 game pieces: https://www.twitch.tv/videos/390621017?t=03h43m58s&ttcontent=textlink&ttmedium=vodembed
- And here's their reveal: https://www.youtube.com/watch?v=KDVPGGb0hj0
- It's different from our robot as a rocket bot, but it is a 6-wheel differential drive like ours, so the way it moves on the field and needs to line up to targets is quite similar to our robot.
- Notice the economy of its movement. Not too fast, but no wasted motion either. Well-practiced arcs/routes that enable efficient alignment to targets. No delays thinking of what to do next - just cycle, cycle, cycle steadily.
- Looking at the reveal video, it seems like their vision camera is seeking just the right-hand-side reflector, homing in on it & driving the robot via closed loop until the camera is aligned with and the right distance away from that single reflector. The camera is located very specifically to line up with that single reflector. @Darwin Clark option for us to consider? Might be able to mount camera off one of the 2x2 climbing leg support structure pieces. Seems like that approach could enable us to also align & position using closed loop all the way until ready to place a game piece.

Darwin Clark
Darwin Clark3:38 PM

Yep, we have been discussing the closed loop solution, and hope to have it ready for wendsday unbag time. In my experience, I'm skeptical of the initial investment by the driver to implement a clean, and efficient closed loop solution. Something we we're really trying to tackle was perpendicular alignment, primarily because on a non-mecanum(spelling?) drive robot, improper alignment with the targets has the highest detrement to cycle times. This would be a good thought experiment to have in person...

Chris Rininger
Chris Rininger4:05 PM

I wonder if analyzing 1690’s cycles from their reveal & from the match video could provide clues. It seems like driver gets in fairly close, then camera light turns on, vision takes over, does a bit of alignment, and places the game piece. They make it look easy (& I realize it is not). Thanks for all your efforts, Darwin! Idea: Maybe they use vision on the one side (& they get distance from it) + just a distance sensor on the other side... use them together?

Mark Tarlton
Mark Tarlton4:48 PM

@Enrique Chee Here's a link to the super glue and accelerator that we used on the printed parts. They sell the accelerator separately as well. I suggest we get accelerator for both the robot room and for the pit toolbox. I think we have glue.

https://www.amazon.com/Bob-Smith-Industries-BSI-157H-Insta-Set/dp/B0166FFCHS/ref=sr13?keywords=super+glue+accelerator+spray&qid=1551833063&s=gateway&sr=8-3

Darwin Clark
Darwin Clark5:37 PM

Chris - Based off of the match you linked on Twitch, I'm unsure weather or not they used vision for alignment, it's likely given the toggleing of their LED ring, but there didn't seem to be a rigid 'shift of control' (Which probably means they have it implemented very cleanly). The ideas you have listed would make good off-season projects...It would be neat to develop all these different 'recipies' during the off-season, then chose one that fits the game challenge well.

Mark Tarlton
Mark Tarlton8:18 PM

If you're interested in 3D printing, here's a video discussing the various materials available for printing -- pros and cons. https://youtu.be/Or1FP43zx3I

2019-03-06
Enrique Chee
Enrique Chee8:14 AM

Ok , I will order.

Enrique Chee
Enrique Chee1:16 PM

Amazon is out of stock . Any other suggestions ?

Enrique Chee
Enrique Chee1:40 PM

ok, I pucrhased this one:

2019-03-18
Darwin Clark
Darwin Clark9:04 PM

@Paul Vibrans @Mark Tarlton (And anyone else interested in working on vision mount variations!) Here is a rough draft document of what we discussed tonight: https://docs.google.com/document/d/1tBMEmYjBNvtltHSbHEbsb88v7Dw65eMHYCmFmicrAU/edit?usp=sharing.

Mark Tarlton
Mark Tarlton9:08 PM

thanks. Do you ever need to plug into the USB connectors (the full sized ones). Do we need to provide access to those or can we cover them up?

Also, we're using Raspberry Pi 3B+ and the current generation of PiCams right?

Darwin Clark
Darwin Clark9:12 PM

@Mark Tarlton Nope, none of the full-sized USB connectors. Raspberry Pi 3B+ is correct. We actually have the rev 1 and 2 picams in stock, but because the rev 1 and 2 make a significant difference with this years vision solution, we are only using rev1. They should have the same / very similar form factor physically.

Paul Vibrans
Paul Vibrans9:13 PM

Where does the SIM card plug in?

Mark Tarlton
Mark Tarlton9:13 PM

I think you told me that they're 5V @2A so they need to dissipate a fair bit of heat.

The PiCam that I have as a fairly large lens compared to the picture you attached. Do both the vision cam and driver cam match the photo you attached with regards to the lens size?

Mark Tarlton
Mark Tarlton9:14 PM

the micro SD card plug in on the bottom side (not shown) of the board on the left side

Mark Tarlton
Mark Tarlton9:15 PM

centered on the connector on the left side.

Darwin Clark
Darwin Clark9:18 PM

The driver camera is going to have a different footprint than the standard raspicams. I don't think the dimensions of the wide-angle driver camera are as-well documented, but here is an amazon link for the driver cams. https://www.amazon.com/SainSmart-Fish-Eye-Camera-Raspberry-Arduino/dp/B00N1YJKFS/ref=sr13?crid=3JCJKLFSV3CMN&keywords=raspberry+pi+wide+angle+camera&qid=1550616462&s=gateway&sprefix=raspberry+pi+wide+%2Caps%2C202&sr=8-3

Paul Vibrans
Paul Vibrans9:45 PM

The SIM card is on the opposite face of the board from the display connector? How thick is the board and how much does the SIM card holder extend from the board?

Paul Vibrans
Paul Vibrans9:47 PM

The link to the Picam physical dimensions does not link to the Picam but to the Raspberry Pi.

Mark Tarlton
Mark Tarlton9:47 PM

the board I have is 1.25mm thick, the SD card sits flush with the back side and is 1mm thick.

Mark Tarlton
Mark Tarlton9:50 PM

well actually, the stack of board, SD socket, etc all adds up to 2.75mm

Mark Tarlton
Mark Tarlton9:52 PM

the back side of the board has other things poking through as well, so it isn't flat.. the tallest objects stick up about 2.5mm above the back surface of the board.

Paul Vibrans
Paul Vibrans9:52 PM

What are the length and width of the SD card holder?

Mark Tarlton
Mark Tarlton9:54 PM

length is 13.4mm. with the SD sticking out another 2.6mm from the edge of the board. the socket width is 12.16mm ...

2019-03-19
Darwin Clark
Darwin Clark10:42 AM

I changed the document to reflect the location of the SD card on the back of the PCB @Mark Tarlton @Paul Vibrans

Darwin Clark
Darwin Clark4:19 PM

@Paul Vibrans Sorry, I had the wrong link copied. Should be fixed now.

2019-03-25
Noah Solomon
Noah Solomon7:58 AM

What is this award for? What does it mean that we can compete for another one?

Noah Solomon
Noah Solomon7:58 AM

(Asking here because I thought engineers might know)

Enrique Chee
Enrique Chee8:09 AM

Great Questions. We will discuss on Wed. at our team meeting from 4 to 6 pm.

Kenneth Wiersema
Kenneth Wiersema8:43 AM

If you’re a interested in what the award is then here’s the page for it on the first website. https://www.firstinspires.org/resource-library/frc/awards-based-on-team-attributes

2019-04-03
Chris Rininger
Chris Rininger9:10 AM

3D printing aficionados, here’s a good DIY article on converting a humble food dehydrator into a filament dryer: https://www.inov3d.net/dehydrator-filament-dryer. Our MarkForged printer has a built-in dry box, but this would probably be useful for our open ABS filament in particular. I’ve had inconsistent results even with PLA, so I’m going to buy a $30 dehydrator and dry out my open stock. Also good for drying out desiccant. BTW, Mark T. said he did this kind of dehydrator mod & it worked for him, which tipped me to researching it & buying one myself.

Mark Tarlton
Mark Tarlton11:55 AM

Yes, it worked for me. I got a 'westinghouse wfd101' food dryer from amazon and it looks exactly like the one in the video. Before drying the filament, I could hear hissing and popping from nylon filament that I was printing with. This took care of the problem. It also helped prints from some PLA filament.

Mark Tarlton
Mark Tarlton12:07 PM

Here's a good video that explains the problem, how to recognize it, and solutions. https://www.youtube.com/watch?v=FAXUjZZER5E

2019-04-10
Dana Batali
Dana Batali7:39 AM

https://www.monoprice.com/product?pid=35435

probably only of interest in the context of robots if you want to make tiny accurate pieces

2019-04-14
Chris Rininger
Chris Rininger12:50 PM

Arms and elevators... It'd be great to be able to be able to confidently choose to use these in our robot designs, but it will take time and work to learn how. If you're interested and have a little time, here are some design walkthrough videos that could help with starting to learn about these mechanisms... They're produced by Adam Heard from FRC973 Greybots, and each one is reasonably short (5 to 20 minutes).

COTS Single Joint Arm Design Walkthroughs: Single joint arm was, by far, the most common central mechanism on low robots that made it to elims at the PNW District Championships. These videos are pretty short and well worth watching.
V1 (worth watching despite there being a V2): https://youtu.be/B1bLacxONlY
V2 (after Vex released a couple new products): https://youtu.be/5SRyYz-tFxQ
Arm motor / gearing selection: https://youtu.be/0TbRbSmwVbo

Cascade Elevator - A full 75% of robots (& 90+% of high-task-performing robots) who made it to elims at the PNW district championships the past two years incorporated an elevator into their design. This is sufficient data to indicate we should be able to choose this option as well.
Part 1 - bearing concepts for 2-stage elevator: https://youtu.be/wZ6a6dc4BGg
Part 2 - cable rigging and power transmission: https://youtu.be/yPG8TGbOqz4
Part 3 - driving stage chain rigging: https://youtu.be/DJrSkXs-5CE
Supplemental short video on COTS bearing implementation: https://youtu.be/GHG1oCbXk
Elevator motor / gearing selection: https://youtu.be/3cRS7TF2KM8

Enrique Chee
Enrique Chee1:15 PM

Thanks for all the research and info. @Chris Rininger

Mark Tarlton
Mark Tarlton1:15 PM

Once you've looked at the videos, try to design something on your own. Start with pencil sketches to get the core elements down, and then think about how it behaves in action -- is it going to bend, break, or fall over? 2D sketches are a great way to start since you can focus on the basic structure. Iterate on the sketches and add details (like dimensions and materials) to the drawings as you go. Think about how it's powered and how the actuator hooks up to the core structures. Once you have a good idea of what you're trying to do, then take it into a CAD program like Fusion 360. I've always found it much easier to learn a tool if there's something specific that I'm trying to accomplish.

At any point along the way, I'd be delighted to chat with you about your designs and how to proceed.

There's really no substitute for actually doing the work yourself.

Chris Rininger
Chris Rininger1:22 PM

:+1: Agree, and I think Adam Heard would also agree. Actually, his most watched videos are about the value (even necessity) of using 2D sketching when designing robots. You might even want to start with these.
Designing linkages with sketches: https://youtu.be/8fQK6IWulSI
Designing robots with sketches: https://youtu.be/XzdzE0L3HY

Mark Tarlton
Mark Tarlton1:33 PM

Another suggestion is to find a 'design buddy' -- someone to partner up with in doing the design and ideally, someone with complementary skills. For example, someone from the CAD team partnering up with someone who knows machinery.

Chris Rininger
Chris Rininger3:50 PM

If interested in working on something familiar, here is an F360 file from January that has height/geometry for cargo pickup and placement locations, plus a couple rough sketched robot chasses. You could study the shared videos and then use this as a workspace for sketching ideas. Link (if you use this, please make your own copy): https://a360.co/2UTJard

2019-04-22
Chris Rininger
Chris Rininger8:52 PM

Since there's a fair chance next game will involve shooting, I'm sharing this COTS turret that came out the past year or so. https://www.armabot.com/products/turret254

Chris Rininger
Chris Rininger10:31 PM

BTW, we could make our own slew bearing. Thingiverse has some interesting designs that could be extended - here's an example: https://www.thingiverse.com/thing:2375124

2019-04-24
Harper Nalley
Harper Nalley3:21 PM

Today I started early designs for arms and I was wondering if anyone would be interested in working with me. If so, speak to me at the meeting tonight or message me via slack.

Harper Nalley
Harper Nalley3:46 PM

^

Terry Shields
Terry Shields6:05 PM

Support for rookie FRC team...

Hey team,
During the Auburn competition this year we met the coach of a rookie team that is looking for guidance. I think we owe it to a rookie team to help anyway we can.

Their two immediate needs are (see her request below):
#1. How to fundraise and lock in sponsors
#2. Problems with robot Drive System


Their team was the Descendants of G.O.R.T. from Monroe - 7627. They have since chosen their new team name:

Quixotic Robotics
Coaches name is: Anna Dahlgren
Mobile phone #: (306)672-1648
Email:



This is the request for help from Anna...

Hello! The team has had some time to process their season and have some goals to work on for the rest of this year. First, they renamed themselves Quixotic Robotics. Now that they have a name they can use year after year they would like to look for sponsors. I was wondering if perhaps your team has a template or an example that we might see. The truth is that they don't even know how to go about asking! And their second question is about the driving mechanism. Theirs was pretty clunky and hard to steer, especially compared to other teams. Do you have any advice on what kind of things they should be looking into? Thanks so much!

We are so very thankful for your willingness to help!!

2019-04-26
Cruz Strom
Cruz Strom4:27 PM

If you interested in how 254 Cheesy Poofs built their turret (and intake), you should look at post #17, #18, and #48 on this Chief Delphi thread. There are even pictures of CAD to help show it better. https://www.chiefdelphi.com/t/254-robot/355746/17

Chris Rininger
Chris Rininger6:54 PM

That is a great share, Cruz! Mentor Andrew Torrance from 254 does a design review of their 2019 robot mechanisms + Q&A. He's a mech engineering student who graduated from 254 in 2015 - really knows how their robot works, obviously. The sketch analysis picture he shared in post 21 is also worth checking out + the chassis CAD rendering near the end. Their chassis seems so simple... 2x1 1/16th aluminum tube with reinforcement in certain places like bearing holes.

2019-04-27
Harper Nalley
Harper Nalley4:02 PM

https://a360.co/2LaSJ19

I used the prefab locking winch design made by Andymark to make a gearbox/drivetrain for an arm or an elevator. I used the existing winch design as a base because it lessens the amount of mill work that would need to be done on a shell, and is already designed for a similar task. While this has 4 motors attached, I don't believe any arm or elevator would require that many. However, I designed it to use up to four motors since we have had problems with under-powering modules in the past. Also, this would allow us to relatively easily add or remove a motor if needed without a complete redesign. Furthermore, it would allow us to make this pre-season since it isn't specialized for a specific robot.
In it's current iteration it is 14" wide, 9.5" tall, and 4" long, but I think I might be able to make it slightly smaller. by making it more compact. I think I can get it down to 13.5" wide and 8.5-9" tall.

Harper Nalley
Harper Nalley4:02 PM

(Ignore the extra stuff floating around it)

Harper Nalley
Harper Nalley5:24 PM

Update
if anyone looked at it before 5:25 PM, I fixed a mistake and its now 12.8" wide

Chris Rininger
Chris Rininger5:55 PM

Glad to see you're working on designs, Lucas! Here are some things I see (others like Paul will see different things):
Upsides
- Power. I like the idea of being able to scale up to as much power as needed.
- COTS. Using off-the-shelf parts can save time (especially if we have the parts in inventory) and simplify assembly.
Other Considerations
- Weight and Space. As you've pointed out, your design is not dainty. If calculations indicate only 1 or two motors are needed, then there would be quite a bit of wasted space.
- Torsion on the 1/2" Hex. If there was a need for 4 motors, that implies a lot of force being transmitted through the 1/2" hex bar. I recall, when Paul designed the climbing winch in 2018 for the potential to climb with friends, he calculated that 1/2" hex (even steel) would deform under the torsional forces. He went with a beefier, larger diameter steel pipe instead as I recall. Paul could tell you (or help you figure out for yourself) if that kind of thing would be an issue here.

Another COTS option to consider for an arm is this Vex clamping gearbox: https://www.vexrobotics.com/vexpro/motion/gearboxes/217-4156.html combined with a few other things like the sliding plastic bearing block (for 2nd gear reduction), a versaplanetary gearbox for further gear reduction, and dual motor input to the versa if needed.

Harper Nalley
Harper Nalley8:48 PM

Thank you for the feedback! To answer the points you brought up, the following goes into some more detail about the module.

Two motor is, I think, the most likely setup for this module. There are two setups for twin motor: the first has them both on the same side and the second has them both on opposite sides at the back.
With two motors the module would be 4"x9.5"x7.5" and it would weigh about 4.9lbs (excluding some bolts and bearings) and I can get that down more if I use a belt instead of a chain. The third motor would add 1.2lbs and the fourth would add 1.8lbs (still excluding bearings). This can also be structural and it has 4 potential orientations.
There is a second way of setting it up with two motors would weigh 3.7 lbs (excluding some bolts and bearings) and it would be 4" x 9.5" x 12.8". I believe this would be the optimal setup if hex bar torsion is a worry since it supports the belt pulley axle (the one in the rear) from both sides.

I will look into stronger options for the hex bar to make this a viable option for tasks that have greater loads. Right now, my solution is going from a 42 tooth belt pulley on the gearbox to something with perhaps 80 teeth on the arm pivot should fix the bar torsion problem.

With minimal modification the module can support up to two Cim/Mini Cim, or Neo motors and it can support up to 4 snowblower or Bosch Seat Motors.

2019-04-29
Riyadth Al-Kazily
Riyadth Al-Kazily9:55 AM

I may have missed this being posted somewhere, but here is an excellent overview of the Cheesy Poofs 2019 robot:
https://youtu.be/CUbA1NEPsdw

Harper Nalley
Harper Nalley1:38 PM

As an update: This CAN hold up to 4 cim/mini-cim motors, but it would probably rip itself apart

Harper Nalley
Harper Nalley10:59 PM

https://a360.co/2PBhX7A

This is the arm robot design I'm working on. Currently it is roughly 45-50lbs (that is including the parts of the drivetrain I haven't actually put in).

FYI, the black rectangle tubes are plastic


Update
It is now roughly 65-70 lbs including the electronics board

2019-04-30
Mark Tarlton
Mark Tarlton4:46 PM

There is now a "Design_Team" slack channel. If you're taking Paul's class, you should join that channel

2019-05-02
Lane Johnson
Lane Johnson7:52 PM

I believe that is correct

2019-05-03
Harper Nalley
Harper Nalley4:32 PM

https://www.youtube.com/watch?v=Paj8XRv0QX8

This is a video that explains what a West Coast Drive is as well as it's benefits and detractions.
To summerise:

Harper Nalley
Harper Nalley4:37 PM

In summery, WCDs are/have
-a lower profile than the KOP chassis
-potentially lighter
-are easier to use various wheel setups than KOP
-Allow for more customization of the gearboxes and allow them to act as counterbalance.
-Are potentially more difficult to build
-Make it more difficult to mount bumpers
-less mounting surface area than KOP

Chris Rininger
Chris Rininger4:57 PM

Thanks for sharing that. I think the team could eventually benefit from developing a custom chassis approach that is used from year to year, and WCD is a very tempting option. It is a very common and proven effective approach for established teams. However, in the near term, I think just developing our design skills and experience along with upping our fabrication abilities are higher priority.

That said, if you would like to start developing your own design, I'd be happy to review it & provide feedback. One way to start: Pull in the Vex VersaChassis pieces to CAD and start fitting them together.

Harper Nalley
Harper Nalley5:13 PM

I agree that this is something for a bit down the road, but I think we can start thinking about it. Once I finish my KOP arm bot and Paul's Arm bot I think I'm going to play around with the WCD chassis as well as Vex's Drive in a Day chassis.

Harper Nalley
Harper Nalley5:20 PM

https://www.vexrobotics.com/vexpro/versaframe/drive-in-a-day/2014-drive-in-a-day.html#Weight

This is another alternative to the KOP chassis. The main upside to this is it's light (roughly 50% the mass of the KOP chassis). The downsides are that it is weaker, it is pretty small (maximum size is 28.5" X 26.5") and it doesn't come with any of the drive train parts.
I wouldn't really recommend this for the last few FRC games but who knows? It might come in handy one day.

2019-05-04
Harper Nalley
Harper Nalley2:32 PM

This is a website I found that was created by 1735 and it is a catalogue collected from the main FRC suppliers of all the parts they sell. It's great for if you aren't sure exactly what you want and don't want to look through several different websites.

Chris Rininger
Chris Rininger2:41 PM

Great find, Lucas! Love the interface.

Harper Nalley
Harper Nalley4:19 PM

http://findrobotparts.com/3d/mounts/
This website also has a library of CAD files for 3D printed mounts

2019-05-26
Riyadth Al-Kazily
Riyadth Al-Kazily11:38 AM

Here's a fun video I found linked from Hackaday.com. It has some creative build techniques, lots of 3d printed parts, and highlights some o the challenges of "drivability":
https://youtu.be/IAB69HGgl8c

2019-06-01
Chris Rininger
Chris Rininger3:22 PM

Wow! I found a new set of resources I'm adding to my list of keepers. Team 2877 Ligerbots share a set of excellent introductory robotics presentations here: https://onedrive.live.com/?authkey=%21AIHEJU8EVHqEAsY&id=1F3974D695C8A0AB%21176221&cid=1F3974D695C8A0AB

The "FIRST Robot Mechanisms" presentation has really broad mechanism coverage... many variations of every type of mechanism you can think of, plus pros/cons. Inspiring to look over them all. And the "FIRST Robots and Strategy" presentation seems designed for introducing new team members to FRC robots and game strategy.

2019-06-02
Riyadth Al-Kazily
Riyadth Al-Kazily7:30 PM

I follow the Ligerbots on Flickr. They have a great photostream, with lots of in-season and out-of-season activities: https://www.flickr.com/photos/ligerbots/

2019-06-14
Harper Nalley
Harper Nalley11:21 PM

https://www.instructables.com/id/90-Degree-Adapter-for-VexPro-VersaPlanetary-Gearbo/

This is a great design for a low profile 90 degree drive From one of the best eastern US teams: 33 Killer Bees. This has the advantage over the standard Vex Versa 90 in that the output shaft is roughly in the same plane as the side of the Versa Planetary Gearbox

2019-06-15
Harper Nalley
Harper Nalley7:38 PM

https://www.strykeforce.org/resources/MechanicalDesignDescriptionofStrykeForceSwerveDriveUnits.pdf

2767 Stryke Force is another top level eastern team and they have multiple swerve drive variants that all have an interesting twist: Coil spring suspension

2019-06-26
Harper Nalley
Harper Nalley11:10 PM

https://www.armabot.com/collections/motion-articulation

Armabot has some really interesting components like a turret and a way to backshafter that allows you to put two 775s in line, or a power lifter

2019-07-02
Chris Rininger
Chris Rininger10:37 AM

Some of you might remember a video of FRC 3339 BumbleB shared during the season because their climbing approach was similar to ours, except they used motor-powered rack and pinion actuators. Well, they published their CAD - here's a link: https://grabcad.com/library/2019-bumbleb-3339-robot-cad-1

And here are part details shared: "We bought the rack from transdev.co.uk. It is 1.25 mod rack made from delrin - very strong. The pinion is 18 tooth 20 dp gear from vexpro."

Separately, here is a modular rack & pinion design from thingiverse. The length of the rack gear can be any multiple of 3". https://www.thingiverse.com/thing:2620620

I could see a reusable linear actuator design using rack and pinion being a solid tool in our design toolbox in the future.

Paul Vibrans
Paul Vibrans2:33 PM

It is interesting to see that they used mismatched components. Perhaps the small tooth count in the pinion let them get away with it. The rack module of 1.25 mm is equivalent to a diametral pitch of 20.32 which can be accommodated by a 20 DP gear with an increase in center distance. As long as the teeth have adequate bending strength, the gear and rack can work together. In general, mixing a 20 DP gear with a 1.25 module gear is bad practice.

Chris Rininger
Chris Rininger2:54 PM

That is an interesting insight. I suspect the small mismatch you describe could result in friction, wear, and inefficiency. The slickness of the Delrin material of the rack gear they used could help (?). If we used 3D printed rack gear segments we might be able to achieve a better fit.

Paul Vibrans
Paul Vibrans7:33 PM

We could find 1.25 module pinions from a source other than the usual suspects. Check www.khkgears.us

Paul Vibrans
Paul Vibrans7:44 PM

Oops, 1.5 module is waaay more common than 1.25 module. Try Stock Drive Products for 1.25 module.

2019-07-03
Riyadth Al-Kazily
Riyadth Al-Kazily11:52 AM

I just learned that NASA publishes a Fastener Design Manual, which can help you understand what nut/bolt to use for a particular application. And I also just learned that split ring lockwashers do not work... https://ntrs.nasa.gov/search.jsp?R=19900009424

2019-07-05
Chris Rininger
Chris Rininger11:13 AM

Looks like this may be the closest 1.25 module gear on that website. http://shop.sdp-si.com/catalog/product/?id=S10T12M018S1010. It costs twice as much and does not have the 1/2-inch hex bore like the Vex 18T 20DP. I suspect they used the Vex one because they already had it in stock, it has the common FRC 1/2-inch hex bore, and they judged the size close enough for the task at hand.

2019-07-22
Chris Rininger
Chris Rininger4:58 PM

Does anyone have a good website or other source for relative strength of aluminum and polycarbonate tube (rectangular & square - the sizes used in FRC) of different wall thicknesses?

2019-07-23
Harper Nalley
Harper Nalley6:38 PM

@Chris Rininger I haven't really looked, but I think the best way to do it is to make a tube of each material in fusion and run a stress test on it.

Paul Vibrans
Paul Vibrans10:04 PM

For tubes, channels, and angles that are smaller than those used for commercial and industrial load bearing structures, there are no published tables of the sort you seek. With spreadsheets it is quite easy to compute the section properties of the tubes using formulae found on the Wikipedia entry for Elastic Section Modulus. Then apply the material properties from a suitable internet search with appropriate judgement because the material properties will be in ranges, not single values.
A textbook on mechanics of materials can be very helpful for explaining what you need to do.
Once you cut big holes in the tubes it becomes necessary to use first principles to figure the strength of the remaining material anyway, so a spreadsheet that can be used over and over becomes really helpful. Besides, you can publish it on Chief Delphi and become famous.
I have a section modulus spreadsheet for really complex, built up, welded sections that I use all of the time, but it is kind of user hostile.

Chris Rininger
Chris Rininger10:45 PM

Thanks for the pointers, Lucas and Paul. From reading and asking around, experience and trial & error seem to be how FRC teams make most tube wall thickness decisions. Deep analysis usually isn't done due to it being time consuming or no one knows how, and because results are usually quite good applying general rules of thumb like...
- Use 1/8-inch wall for chassis + other members under significant strain or at risk of impact (yes, "significant strain" and "impact" are ambiguous - that's where the applied experience comes in)
- Use 1/16th everywhere else, especially anything high up on the robot
- Test thoroughly. If pieces fail, then increase wall thickness (and/or otherwise reinforce at the failure point)

One of the mentors active on Chief Delphi, Ari Meles-Braverman, just published v4 of his FRC engineering calculation spreadsheet: https://www.chiefdelphi.com/t/amb-design-spreadsheet-v4/360145. It has a lot of interesting & useful features, including "Beam Bend" calculator for projecting how much a frame member, manipulator, or axle will deform under different loads. I haven't played with it yet, but people seem to like it as a tool to supplement experience.

2019-07-24
Paul Vibrans
Paul Vibrans7:24 PM

I downloaded the amb design spreadsheet and examined it carefully. The computations are correct but there is no way for an inexperienced person to check to see if the application is the correct one for the problem. The beam bend section is just a deflection calculator. Most of the time we need a stress calculator, which is more difficult to implement in a spreadsheet. I expect someone using this spreadsheet for structural purposes to come up with structures that are heavier than necessary and shafts that are marginal. The column buckling feature is applicable to slender columns that are almost never seen in actual devices.

Paul Vibrans
Paul Vibrans7:29 PM

Beware of spreadsheets that do not show the underlying equations for the calculations. They are very hard to check. They are also hard to adapt to non-standard conditions.

Chris Rininger
Chris Rininger9:49 PM

I gave the author of the spreadsheet similar feedback (just deflection is not that useful) on the Beam Bend calculator, and his response was similar to what you said... it's a lot harder to deal with stress & projecting failure in a spreadsheet. He said the stress simulation / FEA study features of modern CAD packages are a great way to go, very similar to what Lucas also said.

I think many teams (mentors and students alike) use these calculators in the time compressed build season to very quickly get to reasonably close design choices (e.g. a gear ratio for a certain application), and then they refine from there, through testing/iteration. I do really like certain features of the spreadsheet, like the mechanism gear ratio calculator and the projectile trajectory calculator... I'll definitely be using them in conjunction with certain designs. Maybe, in the future, we will create our own version of a design calc tool like this, and we can include the formulas, etc. I agree that would be useful. In the meantime, I think it has some uses, even just to double check outcomes of calculations done manually. It's also fun to play with it... Throw scenarios at it and see what results.

Paul Vibrans
Paul Vibrans10:06 PM

FEA by beginners creates some very interesting problems or perhaps non-problems because of the way the structure gets modeled. I have seen stress "hot spots" that really don't exist except as artifacts of the FEA program. Again there is no substitute for experience.
The spreadsheet can be revised by exposing the formulas; they are all there, just hidden by some Excel function that I have never learned to use. Adding a source reference, like a textbook citation, would be beneficial for those who want to really understand what is going on and dig deeper.

Chris Rininger
Chris Rininger10:27 PM

Totally agree about the formulas helping with learning, and thanks again for taking a look. One thing I just tried that could be useful if this year's game involves shooting - the projectile trajectory calculator. The same could be done using a TI calculator, but not as fast. Here are a couple worksheets I did for Stronghold and Steamworks.

2019-07-25
Chris Rininger
Chris Rininger3:43 PM

After asking him about adding equations/explanations, Ari (spreadsheet creator) ran a survey asking if people would value that, and most said they would. So I expect he’ll be adding that content in a way it can be switched on /off. He said in our chat he excluded that stuff to avoid scaring inexperienced students away from experimenting with the tool.

2019-08-09
Harper Nalley
Harper Nalley9:53 PM

@Mark Tarlton Where did you get the polycord pullies for the cube manipulator redesign in 2018?

2019-08-10
Mark Tarlton
Mark Tarlton1:59 PM

http://www.wcproducts.net/wcp-0097 perhaps here. We had them on hand so I'm not sure.

Enrique Chee
Enrique Chee3:47 PM

Correct

Harper Nalley
Harper Nalley3:48 PM

Thank you!

2019-08-15
Paul Vibrans
Paul Vibrans9:07 PM

I just completed a test version of a 336:1 planetary paradox gear driven by a Denso throttle motor. Free speed is 12 RPM. Output torque is more than I can hold by hand at 12 volt input, about 15 lb-ft. It is suitable for moving the flipper at the end of a scissor lift, arm or elevator. Weight is about 1.25 pounds with all of the bearings and screws, some of which I have not installed because they are on order. I hope installing the missing bearings will make it run more quietly. All parts except the motor mounting plate, screws and bearings are 3-D printed Onyx.

2019-08-16
Chris Rininger
Chris Rininger9:45 PM

@Paul Vibrans There was a update from Ari Meles-Braverman, the guy from Israel who created the engineering calculator spreadsheet you reviewed. He took the feedback that the underlying equations are needed (others said the same thing when he asked on CD). He wrote up 17 pages of equations that he will somehow include with the spreadsheet, and he's now looking for experienced ME mentors to review his work before publishing. I'm not sure you're interested, but if so, see the latest post in this thread: https://www.chiefdelphi.com/t/amb-design-spreadsheet-v4/360145/14

Since Ari designed the spreadsheet to be accessible to students and less experienced mentors, I think it along with the associated formulas could be helpful to our design team.

2019-08-17
Chris Rininger
Chris Rininger11:29 AM

Well, I guess the equations have already been reviewed and he's published them. Here's a link to both the latest version of the spreadsheet and the equations. https://arimb.github.io/AMBDesignSpreadsheet/

Chris Rininger
Chris Rininger12:11 PM

Paul, cool project! I was curious about how the gear configuration looks on the inside, so I put the step file into F360 and hid the casing. For anyone else interested, here's a link: https://a360.co/2Zd41Yx

It take a while to load - be patient.

Paul Vibrans
Paul Vibrans4:52 PM

The promised torque rating is not being realized. Plastic teeth should not run on plastic teeth. I'm starting on a redesign that has metal planet gears.

2019-08-18
Chris Rininger
Chris Rininger10:59 AM

Good read: 254 Cheesy Poof's tech binder from 2019 https://media.team254.com/resources/Team254TechBinder2019.pdf

While we will not be able to do everything they do (since we don't run 7 days a week in a NASA workspace :)), there are certain things we can glean. For example, what encoders and other sensors do they use? They have the resources to test them all, so we can only assume they're making very well-informed choices when selecting those elements.

2019-08-26
Harper Nalley
Harper Nalley10:47 PM

These can be very helpful for weight-savings and limiting the number of motors needed:
https://www.industrialgassprings.com/volume-line/

2019-08-28
Paul Vibrans
Paul Vibrans8:56 PM

The 259:1 planetary paradox gear driven by a Denso throttle motor passed a no-load spin test, if 20 RPM can be called spinning. The change from the previous design was to make sure all meshes had a metal gear driving a plastic gear, which seems to be an improvement. Real testing starts after I modify the torque arm to fit the new output bolt pattern. The spin test "feel" results are much better than the ones with the 336:1 gear with plastic planets meshing with plastic ring gears, even with a smaller reduction ratio.

Chris Rininger
Chris Rininger10:03 PM

I remember reading about someone who tested 3D printed nylon vs nylon + carbon fiber, and the nylon without carbon did better (as applied to that given design they were testing, which included larger, thicker gears than your project). Nylon’s more slippery but also a bit more flexible than the Ny-CF material, so there’s probably a limit to how small/thin gear teeth can be. Still, it might be another interesting variant to try.

2019-08-29
Paul Vibrans
Paul Vibrans5:32 PM

Testing the 259:1 planetary paradox gear is finished as much as it can be. The change to metal pinions running on 3-D printed Onyx gears increased the maximum output torque to 5 lb-ft. before friction stopped everything. The ring gear teeth showed noticeable distortion after just a few revolutions with the load varying between plus and minus 5 lb-ft. Rotation became very unsteady when the load was driving the gear. Output torque of plus and minus 3 lb-ft gave smooth but noisy response during initial testing and a little rougher response after loading to 5 lb-ft. The gear teeth seemed to recover a bit after the load direction was reversed, which makes sense because the teeth would have been straightened up by the load direction change.

Initial running was with unlubricated gears. Quite a bit of brass from the planets rubbed off on the ring gears. Lubricating the gears with Vaseline made continuous running possible at 5 lb-ft output and reduced unsteady response slightly, but it could do nothing to reduce tooth bending from the high torque.

The design is sound for things that do not need more than 3 lb-ft of torque for operation. Output torque is limited by ring gear tooth strength. If we can get ring gears with continuous filament reinforcement, performance should be better as long as we use metal pinions. Larger teeth on the ring gears will be necessary if such a design is to be used with a CIM class motor on the input.

Such a gear driven by a Denso throttle motor could be suitable for a portcullis lifter or for elevating a Stronghold type shooter that is statically balanced around its pivot (not the way ours was built). It would not have worked for the flipper at the end of the scissor lift in Power Up because the combination of power cube and grabber created too much torque on the drive.

The design was dominated by the availability of Denso throttle motors with installed gears and a vast quantity of 16 tooth, 24 diametral pitch gear rod in my material collection. Gear rod with other diametral pitches and tooth counts are available from McMaster-Carr at reasonable prices. We should investigate the possibility of getting metal ring gears 3-D printed by an outside source.

2019-09-02
Chris Rininger
Chris Rininger7:19 PM

Here's a good blog post on 3D printing gears. The post itself has a lot of helpful information, and the author also includes links for more resources. https://engineerdog.com/2017/01/07/a-practical-guide-to-fdm-3d-printing-gears/

Riyadth Al-Kazily
Riyadth Al-Kazily7:44 PM

This is a neat idea to allow 3d-printed gears to be mated to metal shafts: https://hackaday.com/2019/09/02/misuse-this-part-to-attach-3d-printed-stuff-to-a-shaft/

2019-09-14
Dana Batali
Dana Batali8:26 AM

For you gearheads

https://youtu.be/ENFXnNtd3xU

2019-09-15
Chris Rininger
Chris Rininger5:30 PM

Hey all, I mentioned a while back I think a scalable rack-and-pinion-based motor-controlled linear actuator will be a good reusable tool to have in the team's design toolbox. The past 2 or 3 weeks I've worked on a design, and while it's not "done" yet, it's far enough along to share. My goal is to make it quite robust (hence all the aluminum :)) so it could scale to 2+ feet of actuation if needed. The parts I'm not sure about currently:
- How to design & power the 3D-printed pinion to minimize risk of failure. I'm thinking of making it larger and adding hubs on either side with maybe 6 screws through the hubs & gear to distribute force better than just a central shaft.
- Dependent on that, how to set up bearings for the central shaft
- How to best attach the rack gear to the 1x1 aluminum tube
- Aspects at risk of failure that need to be strengthened
- Aspect that are overbuilt to reduce/simplify
- "the little things" like spacers, standoffs, etc.
Here's a link to the work in progress: https://a360.co/2ZUqjyL

Chris Rininger
Chris Rininger10:07 PM

Sort of related, team 1989 continues to push the envelope on use of 3D printing (largely for reasons of cost + they consider it their way to innovate and add something to the FRC world). They're creating an off-season bot they call the "Bumblebot", and one of their mechanisms is a 3D printed climbing solution. Here's a recent thread on it: https://www.chiefdelphi.com/t/3dp-lift/362729

2019-09-18
Harper Nalley
Harper Nalley2:22 PM

@Chris Rininger this looks really good. I just have two questions: did you look at the Armabot 90° gearbox? If not, you can find it in SpartronicsCAD/Downloaded Parts/Gearboxes/With Motors. Its a low-profile gearbox that can sit nearly flush with whatever it is attached to. Second: did you look into the viability of attaching a constant force spring for when it is needed to lift something?

2019-09-21
Chris Rininger
Chris Rininger1:01 PM

Hey @Harper Nalley, I finally took a look at that other 90° gearbox. I agree it may work better than the Vex one for the reason (nearly flush mount) you suggest. I also like that the design is made to accommodate any output length shaft out of the box rather than having to switch the stock-length shaft with a female hex drive replacement (more cost) to get a custom shaft length. Thanks for the tip!

As far as using a constant force spring, I regard that as an augmentation to be made if needed. If the actuation is lateral with just as much max load in one direction as the other, then not needed. If the actuation is vertical with a constant load in one of the directions, something like that would be good to add.

2019-09-23
Mark Tarlton
Mark Tarlton12:49 PM

Here is a blog post on CNC machining vs 3D printing. It's an easy read with links to other blog posts.
https://markforged.com/blog/cnc-or-3d-print/

2019-10-14
Mark Tarlton
Mark Tarlton2:14 PM

At the BARN, we just got the CNC plasma cutter working. Here's a video of an early test cut by Mark McComsey -- 0.125" thick aluminum
https://vimeo.com/366139327

Dana Batali
Dana Batali2:23 PM

wow! any sense of the smallest feature size one could obtain at this thickness? Could it "drill" a small hole?

Mark Tarlton
Mark Tarlton2:26 PM

I think the cut width is on the order of 3/32" wide . That's what I remember from the first cuts. The cuts are somewhat rough as well. Not nearly as clean as a waterjet but the speed is really nice!

Paul Vibrans
Paul Vibrans3:11 PM

That is exciting! Plasma cut parts on our next robot!

Chris Rininger
Chris Rininger3:54 PM

I wonder is we could conceive a workflow using the xcarve for iterative plywood prototypes/test mechanisms and then, once perfected, ask BARN to cut the final designs in aluminum. A lot of teams talk about gaining a lot of value from this. In fact, Bear Metal demoed rapid creation of a plywood basketball shooting mechanism prototype on Saturday (they have their own plasma cutter of course)

Chris Rininger
Chris Rininger4:53 PM

Here’s an often-referenced Instructables article (more like a short book), that includes a lot of sheet metal design concepts. https://www.instructables.com/id/How-to-Build-your-Everything-Really-Really-Fast/

2019-10-16
Steve Erickson
Steve Erickson8:36 PM

@Steve Erickson has joined the channel

Chris Rininger
Chris Rininger10:07 PM

During the leadership team meeting this evening, the extensive FRC "roboting" overview below was mentioned as a resource. Most all types of robot elements are covered, except software. This is HIGHLY recommended for everyone to review (new and experienced people). I recommend studying the whole thing, even the sections that fall outside your sub-team, because this information can really help you understand what all the general robot pieces are & how they fit together. Hope you love it! If you're looking for more after this, let me know.

2019-10-19
Chris Rininger
Chris Rininger8:27 AM

I found this deep discussion about shooter/launcher design from last May. There is a lot of great FRC community wisdom in there. https://www.chiefdelphi.com/t/idiots-guide-to-making-good-shooters/357638/1. One thing seems very clear: with these mechanisms there will need to be prototyping (i.e. well-designed experiments with game pieces + design options) to test certain variables before final design. FRC game pieces are too unpredictable to just design & CAD using intuition about how the game pieces will behave. Check out posts 4, 5, 8, 12, 18, 37...

2019-10-27
Harper Nalley
Harper Nalley12:39 AM

@Paul Vibrans do you think it would be worth it to use steel for the long rectangle tubing in a scissor lift? I ran simple structural analyses on two 1"x2"x25" rectangle tubes, an aluminum with thicknesses of .1" and then a steel one with a thickness of .033" and while there is a difference, it seems to be minor.
ALUMINUM:
https://drive.google.com/file/d/1Yes-N83OrqKZtyDkvaDUu-NoMvQ-3T9Y/view?usp=sharing

STEEL:
https://drive.google.com/file/d/1JwZbixNimjk-YUzIXhPEUh6Oj2qgSG1t/view?usp=sharing

I know that this isn't a completely accurate simulation of the forces the tubes would be subjected to, I just threw this test together to see if it might show me whether or not the use of steel over aluminum was worth pursuing.

Paul Vibrans
Paul Vibrans10:58 AM

Great analysis. The slightly lower deflection of the steel is due to the higher modulus of elasticity for steel combined with slightly more steel on a density basis. For perfect weight match, the steel tube would be only 0.0283 inches thick. I favor aluminum because it is easier to work with than steel, particularly such thin steel. I get more cuts on my fingers working with steel than working with aluminum. Another thing to check is availability of steel rectangular tube in the wall thickness you want. The thinnest I could find on line was 18 GA or 0.053 inches thick.

Harper Nalley
Harper Nalley1:31 PM

Okay, thank you! What about carbon fibre? Do you think it might be an effective enough weight-saver to justify the cost?

Chris Rininger
Chris Rininger3:11 PM

We've talked about servos before as a good option for certain things. Here's a video showing how much power the strongest servos legal for FRC may have. (The rule is they need to cost < $75 as I recall.) A servo is manipulating a 12-inch long arm holding a 13 lb battery. https://youtu.be/nBCaE7FjXY0

2019-10-31
Declan Freeman-Gleason
Declan Freeman-Gleason3:47 PM

This is an interesting development in the world of FRC brushless motors: https://www.vexrobotics.com/vexpro/falcon-500

CTRE claims that all of the specs are better than the NEO.

Harper Nalley
Harper Nalley6:10 PM

@Enrique Chee I just checked the CAD and the Cim and Neo are identical when it comes to their mounting holes and output shaft.

Enrique Chee
Enrique Chee6:11 PM

Great. How about the new vex motors ?

Paul Vibrans
Paul Vibrans6:54 PM

The VEX motors have splined output shafts that have 14 teeth and 8 mm outside diameter. CIM motors have 5/16" (7.94 mm) outside diameter shafts with a single keyway. MiniCIM and NEO motors have 8 mm outside diameter shafts with a single keyway. The things that fit on CIM motor shafts will fit on the new VEX motors if the key is filed to nest in the splined teeth. Gears with 0.5 module teeth will mesh directly with the spline teeth. Be aware that 0.5 module teeth are smaller than the 0.75 module teeth that come standard on Denso throttle motors and may be too small to print accurately on the Onyx printer.

Chris Rininger
Chris Rininger7:02 PM

The Falcon 500 is only slightly better than the Neo+SparkMax, spec and weight wise, but it could be an easier leap than the Neo given the integrated Talon motor controller that I assume will be familiar to program to anyone used to Talons. The separation of the motor controller from the motor with Neo might end up being an advantage to the Neo in terms of fitting into tighter spots (and also avoiding risk of lowing the whole controller+motor if one element fails). It'll be interesting to see which motor rises to the top when it comes to drivetrains... seems like advantage Falcon possibly. As far as as adapting the Falcon to places where a CIM would go, I have to think there will be straightforward options available... it's too obvious an opportunity. One more factor: it costs $140 which is $25 more than Neo+SparkMax.

Declan Freeman-Gleason
Declan Freeman-Gleason7:12 PM

It doesn’t matter to the programming team which we use. All our code is set up so that we can easily switch between the Spark Max and CTRE Phoenix controller libraries.

Just in case anyone was wondering.

Chris Rininger
Chris Rininger7:20 PM

I remember something from last year about the Neo encoder output being lower resolution or otherwise harder to work with than the Talons... not the case?

Declan Freeman-Gleason
Declan Freeman-Gleason7:22 PM

The resolution is lower, but the bigger issue is that the encoder is attached before the gearbox, so you can get backlash (which is less of an issue if you’re running the motor to a specific nonzero velocity).

Harper Nalley
Harper Nalley8:06 PM

@Paul Vibrans performance-wise, how much better would you say the Falcon 500 is compared to the NEO?

Mark Tarlton
Mark Tarlton8:13 PM

@Harper Nalley Have you looked at the spec sheets for the two motors? Last spring we talked about motor power, efficiency, and speeds.. I'd be interested to hear your thoughts on the two motors first..

Harper Nalley
Harper Nalley9:22 PM

@Mark Tarlton
Mechanical Application
I would say that the benefit is potentially quite significant, but only in certain circumstances. For drivetrains if given the choice I would go NEO because they're smaller in spite of the fact that they can't use the small gears that the Falcon can. Really, there are very few instances where I can see a Falcon giving a huge advantage. Initially I thought they could be great for an heavy arm or elevator because they have a significantly higher torque rating than a NEO, but honestly, I think both should be counter-sprung enough to where the motor is mostly dealing with positioning, not lifting. If used in a climber, however, they could be VERY helpful because of that higher torque rating and THIS is where I think they could be very important in this coming year. Also, when it comes to shooting with a flywheel design, these could be very helpful for the same reason.

Electronics
When it comes to electronics and wiring, I am skeptical. The integrated motor controller sounds great, but from a wiring perspective is potentially really annoying. I understand the benefit of keeping the MC with the motor; but the fact remains that there will be four more wires going to the motor thus creating more that can (and in all likelihood will) go wrong. Keeping the MCs in one place is really nice cos it cuts down on the amount of work electronics has to do. I'd REALLY like to test the whole keeping MCs and motors together idea before we ever use it on a competition robot.
Then there's the fact that the MCs are integrated meaning if it dies (to my knowledge), we'd have to replace the entire motor which often isn't all that easy (take the wrist-actuator CIM on THEMIS for example).

Overall
In total, I think we should order four of these the moment we can. Also, I think we should REALLY try to limit ourselves to one on this years robot and bring all three extras to each competition as backup. I really like the increased torque and stall current which is where this blows the NEO out of the water. I LOVE the cooling port and I quite like the new output shaft. I am skeptical of the integrated motor controller and I don't think this is really the massive step forwards a look on CD would imply. It's important to remember that the difference between a Falcon 500 and a NEO is nowhere NEAR the difference between a NEO and a CIM when all things are considered. I think it's also important to keep in mind that this is unproven and we don't know how well this will actually end up working. It's just like how you don't want to buy a car from the first year that the model was made.







I also love the name.

Mark Tarlton
Mark Tarlton9:25 PM

One other thing I like about the Falcon is that they have provisions for hard limit switches. That's nice as absolute protection against overshoot if we take advantage of it.

Paul Vibrans
Paul Vibrans9:43 PM

I can't be sure of the Falcon performance. The NEO performance was published in two forms, one that I believe did not include the effect of the controller, and one that did. The performance of the NEO with controller is comparable in quality to the performance curves for a CIM. The power claims for the Falcon seem at first look like the power claims for the NEO without controller.

I perceive a lot of ad speak in the technical description. We should buy one and install it on something where we can replace it easily with a CIM.

One thing that bothers me about both NEOs and Falcons is that I can't test either one with just a battery and a switch. I don't think I can test them even with a 12 volt 3 phase power supply if I had one. Sometimes during system setup it is important to run things without a fully functioning RoboRIO connected.

Chris Rininger
Chris Rininger11:36 PM

The SparkMax controllers for the NEOs have a USB testing mode, so you could theoretically test with computer, 12v power supply, SparkMax controller, and the motor. Not sure if Falcon has anything similar. Our motor tester rigs probably don’t work with either motor, so figuring our test rigs is probably on the list of To Dos with any brushless motor we decide to try. There’s a new, smaller Neo motor as well by the way.

2019-11-01
Riyadth Al-Kazily
Riyadth Al-Kazily10:43 AM

Both the Falcons and the NEO Spark Max controllers accept PWM control signals (in addition to CAN bus), so they can be driven using our PWM motor test tools (variable speed, forward and reverse). We don't need a full RoboRIO to make them move.

Harper Nalley
Harper Nalley9:01 PM

@Paul Vibrans @Mark Tarlton
https://a360.co/2BLgSUw
This is a design for a late 2018-style grabber that uses no pneumatics and a limited number of motors. I was wondering if a 3D printer could print the five belt pullies I've designed or if they are outside the capabilities of the markforge.

Mark Tarlton
Mark Tarlton9:57 PM

The belt pulleys are printable. We did some on last year's robot. the belt crossing looks to be a problem though..

If we have a sold grabber, the intake mechanism may not be really necessary..

If you give up the intake, then you can put a drive motor on each arm and eliminate the pulleys and belts altogether. That might be a perfectly acceptable option ..

Chris Rininger
Chris Rininger11:49 PM

The crossed belt thing is cool, but I’ve only seen it done with urethane round belt or the like. Even with round urethane belt, I’ve read that teams have troubles with rubbing friction and wear when crossing belts. I see the crossed belt approach on prototypes more than final designs, possibly due to that.

2019-11-02
Harper Nalley
Harper Nalley1:31 AM

The other option could be crossed bike chain

Harper Nalley
Harper Nalley1:35 AM

With this I attempted to design something more complex than a solid grabber because this just has more problems to solve and every once in a while an adjustable intake would be quite helpful. I'd definitely like to do a real-world test of the crossing belts and a crossing 11 or 12 gear bike chain.

Chris Rininger
Chris Rininger9:33 AM

I’ve only seen crossed belts personally, not chain. Research it & see what you find.

Harper Nalley
Harper Nalley9:34 AM

Will do

Chris Rininger
Chris Rininger10:19 AM

Found this - I'm sure there are better resources, but it does discuss some of the issues, including friction necessitating a max distance between pulleys & max speed. I assume periodic inspection & replacement would also be needed due to the friction.
http://www.engineersgallery.com/types-of-flat-belt-drives/

Harper Nalley
Harper Nalley11:36 AM

I figured out how to get rid of the problem on the bottom belt, when I get home later I'll CAD up the solution. As for the top belt: since it isnt going to be moving all that much, I would be very surprised if an issue arose.

Paul Vibrans
Paul Vibrans2:11 PM

A better solution to these belt woes is to introduce a gear mesh that changes the direction of rotation. Shaft spacing can still be achieved with belts, but the pulley at one end would drive a gear that meshes with another gear that drives the output. Printing gears is easy. The pulley/gear combination would require an idler shaft, but that is easy too. Since the arms can't rotate full revolutions, there are multiple options for connecting them, the simplest of them being a push-pull link that follows the path of half of the crossed belt. If you insist on a belt, cut it, give it a half twist, and connect the ends with rods that connect the edges and pass above and below the twisted portion.

Paul Vibrans
Paul Vibrans2:16 PM

A friend of mine used crossed bike chain in the double differential drove of his kinetic sculpture. He had trouble with chain tension and hopping off sprockets initially. In the end he had to put guides on the sides of the sprockets and run the chain quite loose to keep the link pins from catching. This was with gravity working along the chain axis rather than across the chain axis as it would be with a grabber.

Harper Nalley
Harper Nalley3:14 PM

Okay, I figured out a way to fix the crossing belt issue for the bottom belt

2019-11-03
Harper Nalley
Harper Nalley3:26 PM

https://www.servocity.com/

This is a potentially helpful resource for parts. They're mostly FTC-focused, but we could probably use some of their offerings

Harper Nalley
Harper Nalley9:39 PM

@Paul Vibrans @Mark Tarlton @Chris Rininger I think I fixed the problem with the bottom cross belt

2019-11-04
Chris Rininger
Chris Rininger10:01 PM

So just to make sure i understand what you're trying for... It looks like you have a car window motor that will open/close the arms and a CIM that will spin intake wheels (at least two of which still need to be added further out on the arms as well as the sync belt pulleys)?

2019-11-05
Harper Nalley
Harper Nalley12:36 PM

Correct, the motor being used for positioning the arms is a Bosch Seat Motor. I chose it over the Snowblower motor because the free speed is 24rpm on the former and 100 on the latter. The motor for the wheels is a BAG motor. I chose it over the 775Pro because it has a stronger wire connection (it's also slightly lighter at 11.3oz and has a stated free speed rpm that is 5000 lower than the 775Pro).

Mark Tarlton
Mark Tarlton4:34 PM

One aspect you should consider is the torque of both motors. We tried to use the arms to grab the cubes. So there needs to be enough force (torque) generated by the seat motor to squeeze the arms in enough to hold the cube .. and even enough to slide it on the carpet into the proper position.

the pneumatic cylinder we used produced about 25 lbs of force and we had it mounted 2 or 3 inches away from the pivot point.

So, it's not just getting the arms to move into position, it's about them applying enough force to do the work they need to do

Harper Nalley
Harper Nalley5:13 PM

I'm trying to design something with a pull coil spring

Chris Rininger
Chris Rininger5:30 PM

Interesting write-up on 3D printer nozzle size selection. The larger nozzle option for robotics applications seems worth investigating, given the advantages (though not for the MarkForged I assume). I bought an 0.8mm nozzle for my own printer but have yet to try it. Anyone tried printing with a larger-than-standard nozzle? https://grabcad.com/tutorials/picking-a-nozzle-for-your-3d-printing-project

Mark Tarlton
Mark Tarlton5:44 PM

My printer has 0.5mm which is slightly larger. They also offer a head with a 1.2mm nozzle and 3mm filament. To run that much plastic through the nozzle, the hot end needs to have enough power to melt that much plastic.

2019-11-06
Declan Freeman-Gleason
Declan Freeman-Gleason6:54 PM

@Declan Freeman-Gleason has joined the channel

2019-11-07
Max Morse
Max Morse12:22 AM

@Max Morse has joined the channel

Jiana Lyons
Jiana Lyons6:40 AM

@Jiana Lyons has joined the channel

Harrison Wilder Wilkinson Bennett
Harrison Wilder Wilkinson Bennett7:54 AM

@Harrison Wilder Wilkinson Bennett has joined the channel

Zephyr Kochenash
Zephyr Kochenash1:05 PM

@Zephyr Kochenash has joined the channel

Ian Cosman
Ian Cosman5:19 PM

@Ian Cosman has joined the channel

Chris Rininger
Chris Rininger6:15 PM

I saw this option came out for 8mm shaft + keyway on the Falcons: https://www.thethriftybot.com/store/PRE-ORDER-8mm-Keyed-Motor-Output-Shaft-p157387731

Melony Bourgeois
Melony Bourgeois6:54 PM

@Melony Bourgeois has joined the channel

2019-11-08
Garrett Swanson
Garrett Swanson11:24 AM

@Garrett Swanson has joined the channel

2019-11-09
Dana Batali
Dana Batali9:52 PM

wow! I'm sold. This seems like a very nice route to brushless motor goodness. Also simplifies a lot. Haven't seen the price tag though.

https://www.youtube.com/watch?v=NPxq60JhGM4

2019-11-10
Dana Batali
Dana Batali10:27 AM

https://www.vexrobotics.com/vexpro/falcon-500

cost is $139 (includes motor, encoder and controller)

Paul Vibrans
Paul Vibrans10:00 PM

2019-11-13
Freeman Tuohy
Freeman Tuohy12:37 PM

@Freeman Tuohy has joined the channel

2019-11-14
Paul Vibrans
Paul Vibrans2:58 PM

@Paul Vibrans has left the channel

Paul Vibrans
Paul Vibrans2:58 PM

@Paul Vibrans has joined the channel

Paul Vibrans
Paul Vibrans3:04 PM

The Dynamo Brushless Motor runs at half the speed of a Denso Throttle Motor with about 2.5 times the torque for the same current. It is more efficient and WAY heavier. The real market for these motors is industrial, not robotics, at least not FRC.

Harper Nalley
Harper Nalley3:09 PM

Yeah, I read a bit more on CD and found someone who said something similar. Nobody is quite sure why AM is selling them

Paul Vibrans
Paul Vibrans3:14 PM

Probably nobody in the industrial world had a use for such a wimpy motor and they got dumped on the surplus market. I bet AndyMark bought boxes of them for cheap without knowing how useless they really are.

David Scheiderman
David Scheiderman8:56 PM

@David Scheiderman has joined the channel

2019-11-18
Mark Tarlton
Mark Tarlton5:27 PM

This was posted on the BARN slack channel. There is a metal supplier that offers pieces of aluminum machining plate in various sizes and thicknesses at $1.00LB. Several alloys are available including 6061, 7075, and mic6

You enter the min and max for thickness and width, and the max length. Their search will return a list of what's available.

https://www.howardprecision.com/random-rack

Paul Vibrans
Paul Vibrans9:03 PM

Actuator tests went well today.

A Denso throttle motor direct driving a steel 3/8"-12 ACME screw in a 1" thick UHMW polyethylene nut was able to lift 23 pounds at about 1/2" per second using 6.37 volt input. The nut was connected to the weight so that there was no side load or moment. Speed was much faster with 12.63 volt input and more than 25 pounds could have been lifted with the greater voltage if I had not run out of test weights.

A 277 to 1 paradox planetary gear driven by a CIM motor produced 18.3 output RPM at 12.0 volt input with 4 A current. Limitations of the power supply prevented accurate testing above 8 A current. When connected to a 12 volt battery of questionable condition, the motor and gear combination could not be stopped by hand, a torque of about 10 foot-pounds. I will test to 40 foot-pounds tomorrow.

2019-11-27
Henry First
Henry First3:41 PM

@Henry First has joined the channel

2019-12-09
Paul Vibrans
Paul Vibrans8:05 PM

I finished testing the 277 to 1 paradox planetary gear driven by a CIM motor. Maximum steady torque was 37 foot-pounds with 12.6 volts to start and 12 volts to end. This much load pulls the battery voltage down very fast to about 10 volts on the second revolution, at which point the system stalls. The system will not accelerate from a stop with more than 14 foot-pounds of load torque at 10 volts.

I performed the testing with a weighted arm that produced both positive and negative torque. The gear is non-overhauling, which means it does not free wheel (drift backward) when the torque goes negative. This caused nasty starting and stopping when a large rotating weight descended. Smaller weights were not as active. A viscous damper attached to the arm smoothed out some of the motion. Some kind of damper may be necessary in a real application.

The extreme dynamics when lowering the arm with the heaviest weight have loaded the gear teeth more than I expected without obvious degradation. There appears to be enough margin in the design to handle the extra torque delivered by a Falcon 500 motor should we wish to test one.

2019-12-10