10-08-2009 11:05

Stephen of REX

Re: pic: We got bored :)

Cool metal work, but what does it do?

10-08-2009 11:14

Jared Russell

Re: pic: We got bored :)

I believe it is the world's smallest swerve module.

10-08-2009 11:38

Chris is me

Re: pic: We got bored :)

Heard a little about this, pretty much the neatest little swerve that you ever did see... Looks neat to say the least. Smaller than a kit wheel this year.

10-08-2009 13:03

BrendanB

Re: pic: We got bored :)

How much does that little thing weigh?

10-08-2009 14:44

Dillon Carey

Re: pic: We got bored :)

here's a picture of the other side:

It weighs about 1lb 5oz.

the Height from the turning sprocket to the bottom of the wheel is about 3 3/8"
(the wheel is 1 5/8" diameter, 1.625 )

10-08-2009 14:45

EricH

Re: pic: We got bored :)

What motor does it use to drive?

10-08-2009 15:05

Dillon Carey

Re: pic: We got bored :)

whatever motor you wanted to connect to the vertical axle, i would guess a cim in most cases.

10-08-2009 15:22

NorviewsVeteran

Re: pic: We got bored :)

If you want a digital camera to focus that close, set it to macro (the little flower icon).

Neat design in the sides there

10-08-2009 15:58

Big Kid

Re: pic: We got bored :)

extremely neat, I remember our prototype swerve module (never made it to the robot) was like 5x heavier and bulkier, i like the design too really neat

10-08-2009 16:14

Dillon Carey

Re: pic: We got bored :)

thanks for the tip

10-08-2009 16:18

daltore

Re: pic: We got bored :)

Any pictures of the innards? Sweet design, I'd love to see that on an FTC robot (if they would allow it along with all the other parts needed).

10-08-2009 16:42

Dillon Carey

Re: pic: We got bored :)

If there aren't limitations on the wheels there shouldn't be any reason not to put this on an frc bot.

10-08-2009 17:30

GarrettF2395

Re: pic: We got bored :)

Wow!
I'm always really impressed by your teams quality of components!

Two questions for you:
1) From the beginning of the design process, to having a finished product,
how long did it take your team to complete this project? (Just wondering)

2) Do you have an idea of how much load this little guy can take?

10-08-2009 17:55

Dillon Carey

Re: pic: We got bored :)

Its the off-season so we have been taking it nice and easy, we have probably been working on it for over a month, if you take out design and it probably took 3 days.

In a build season environment we could probably have 4-6 of these done in 3-4 days (give or take a few depending on when the waterjet is open and when we can get the hex put in the bevel gears and axles made).

The wheels would be the weakest point, in my opinion, since everything else is .25" plate and .5" hex.

http://banebots.com/pc/WHB-WS-174/T40P-174BO-HS4 is where we got the wheels, but i can't find a number for how much they can hold, although I'm pretty sure that having 3 wheels per module and having 3-4 modules on a robot that the wheels would be fine.

10-08-2009 22:58

Jared Russell

Re: pic: We got bored :)

The only caveat of such small wheels is ground clearance. If next year's game requires climbing a ramp or other obstacle, big wheels become valuable.

10-08-2009 23:03

Andrew Schreiber

Re: pic: We got bored :)

Simswerve... always a good thing to bring up, just because there is an obvious solution does NOT mean it is the only solution. With modules this small and light you can really do some cool stuff.

10-08-2009 23:08

AdamHeard

Re: pic: We got bored :)

On a similar note, for a game like 04; Why even tackle some problems? Hanging from the floor in 2004 was a negligible (1'?) difference in height compared to hanging from the platform. Always double check that a problem is really a problem.

10-08-2009 23:15

Greg Needel

Re: pic: We got bored :)

I love this. The FIRST community never ceases to amaze me with their ideas which I probably would never have thought of, this idea is one of them. I can totally picture this on an FRC robot, tucked away inside a 3x3 or 4x4 frame rail. It could be an almost "hidden" drive train as it would take up a very small amount of real estate.

As for the wheels, I have heard mixed reviews about the banebot wheels. Just like any traction devices harder wheels don't provide enough traction and the soft wheels wear too quickly. A unique opportunity you have with a 3 wheel design is a mixture of wheel durometer, while I am not sure you may be able to "tune" your traction using different combinations, the one that strikes me as obvious is high traction on the inside and harder wheels on the outside.

A couple of questions:

Any reason you didn't use gears or even #25 on the outside, I would suspect you could play with the geometry a bit and make gears work making assembly even easier.

Do you think you really need ball bearings in the modules? I think you could get away with oilite bronze bushings to keep the space and weight lower.

Did you think about drilling out the hex shafts to reduce weight? you could probably sink a 1/4 hole through your shafts and loose even more weight.

Overall I really like the idea, and don't be surprised if I borrow some of these ideas for a future robot.

10-08-2009 23:22

Aren_Hill

Re: pic: We got bored :)

that is #25 chain.....also those bolts are #6's for size reference

and the bearings are the 1/2" hex bore andymark ones enabling us to use the banebots wheels without custom hubs and not having to make spiffy shafts just buying some 1/2" hex stock and adding snapring grooves

we also have always used bearings in all spots on the drive out of just a nagging feeling bushings hurt efficiency we like the bots flying (not quite 254 but close).

Yeah i suppose we could bore out the shafts it would be quite easy, we'd thought of that and it would probably happen on the final version of a real bot. Also the Hex shaft is 2024 alum.

And we went for the orange wheels for the fact our team colors are orange and black and this one is for proof of concept and show, final we'll play around more

another awesome part about this is you can add 1 reduction between a cim and the input shaft and have a reasonable speed, no weight wasted on extra reduction to get to say a 6" or 8" wheel

Piloted and designed by Dillon i was just a consultant

11-08-2009 00:33

NorviewsVeteran

Re: pic: We got bored :)

Any chance of another beauty shot, next to a quarter or ruler or something?

11-08-2009 01:01

Akash Rastogi

Re: pic: We got bored :)

I go to visit MIT for one weekend and this is what you do, Aren?

Great stuff.

11-08-2009 01:12

R.C.

Re: pic: We got bored :)

This is like the coolest thing I've seen all summer. It reminds me of a lego version of a big swerve, not that is not usable. But it fits like one aka the notches and I love it (PUZZLE SWERVE). I second Greg, I may use this idea in the future.

Hats off to you guys for the wicked design.

-RC

11-08-2009 01:23

Dillon Carey

Re: pic: We got bored :)

11-08-2009 01:32

Greg Needel

Re: pic: We got bored :)

how come the wheels are not centered?

11-08-2009 01:57

Dillon Carey

Re: pic: We got bored :)

The wheels aren't centerd because in order to make the module shorter we had to offset the wheels from the bevel gear

11-08-2009 01:59

AdamHeard

Re: pic: We got bored :)

WOW. that pic with the quarter totally changed my concept of the scale. that is TINY.

It looks like they might hit the bevel gear if shifted to the left at all.

11-08-2009 11:48

Brandon Holley

Re: pic: We got bored :)

Very impressive guys! I have an extremely similar design in development for part of my senior design project. Please keep us up to date on those wheels as your testing. The polypro hubs seem like the big question mark for me. Also, just to confirm...how do you guys hold the vertical miter gear on the shaft? Looks sweet!

Brando

11-08-2009 13:56

JesseK

Re: pic: We got bored :)

Very impressive, though I'd worry about wheel tread wear if it's soft rubber.

11-08-2009 13:57

Dillon Carey

Re: pic: We got bored :)

The vertical bevel gear is held on by a snap ring.

12-08-2009 14:32

EricH

Re: pic: We got bored :)

I gotta agree. I held a quarter up to it... It's just barely larger than life in the picture.

You better let us in on test results on this one...

12-08-2009 14:39

AndyB

Re: pic: We got bored :)

Love it, love it, love it.

You should get a shot of the mini next to one of your full size boxes from last year (if you still have an extra one lying around).

Great job.

13-08-2009 16:05

M. Mellott

Re: pic: We got bored :)

Really nice job, guys!! Can't wait to see these on a test chassis!!

13-08-2009 22:33

Josh Fox

Re: pic: We got bored :)

*double take at picture with quarter*

Wow. That's extremely impressive, way to push the creative envelope. I can't wait to see more on this module in the future.

14-08-2009 00:19

gallo26

Re: pic: We got bored :)

thats extremely awesome! solving the problem of swerve modules being WAY too heavy!! Very cool!

Now this might be a stupid question, but my team has never worked with modules like this, and I'm hoping to actually get my team into it. But how does the module stay mounted in place? Like, what keeps it in its place and allows it to rotate? some platter bearing? I guess i just don't see it... Thanks in advance for answering that!

14-08-2009 11:45

Jonathan Norris

Re: pic: We got bored :)

Wow!! that picture with the quarter just freaked me out how small these are... I guess my only concern would be with what they are rotating on seeing how small they are... These wheels are super impressive and have my mind spinning with new ideas...

14-08-2009 15:58

hillale

Re: pic: We got bored :)

I'm pretty sure the current rendering has the lower disk nested in a complementary ring of delrin or the like which is mounted to the frame. Three of our members (including Dillon) are currently on a camping trip. Dillon's mom got a call today letting her know that they're working on designing a drivetrain for next year's game.

14-08-2009 16:10

sdcantrell56

Re: pic: We got bored :)

If these wheels dont hold up you could look into making your own tiny wheels and pouring urethane tread on them like 125 did in 08. I think colson makes some pretty tiny wheels as well and they would definitely hold up much better.

14-08-2009 16:11

EricH

Re: pic: We got bored :)

Would that be the water game, the flying game, or the Martian game?

14-08-2009 19:32

Chris is me

Re: pic: We got bored :)

Why would you go camping to design the drive train... wait a second it's a GAME HINT!

14-08-2009 21:11

Aren_Hill

Re: pic: We got bored :)

These will have a thrust roller bearing at the top that can easily handle the load these'll see, pushing up against a flat plate bolted to the frame, at the bottom a delrin or UMHW right will encircle the disc of the module.

Dillon does have a frame cadded up, but as of now we do not plan on completing a full prototype for money reasons. We will on the other hand be putting this on a setup with an old chassis and 2 casters and seeing how it lasts durability wise at the very least.

14-08-2009 21:26

Akash Rastogi

Re: pic: We got bored :)

Have you looked into using Teflon sheets? That stuff is pretty awesome compared to UHMW

15-08-2009 22:22

Aren_Hill

Re: pic: We got bored :)

ahem, If you do use these wheels, never spin them on carpet. The tread kinda leaves in a unelegant fashion (ow).

We'll be pursuing colsons and also the prospect of making our own

18-08-2009 11:53

Dillon Carey

Re: pic: We got bored :)

Not pretty

18-08-2009 12:29

JesseK

Re: pic: We got bored :)

I'm thinking Baltic Birch wheels with riveted Roughtop tread for production, or whatever wood you can find for prototyping in the meantime. You could make them whatever diameter you wanted to, however wide you wanted to, and it would be one solid wheel.

This also shows the rest of us that the BB wheels probably wouldn't hold up very long in an overall FRC season for a defensive-type bot.

18-08-2009 12:38

Brandon Holley

Re: pic: We got bored :)

Can you guys elaborate on your test setup for this??

Thanks
Brando

18-08-2009 12:46

Chris is me

Re: pic: We got bored :)

What durometer of polyurethane were you guys using? That looks soft enough that you could just peel it off if you wanted....

18-08-2009 15:20

Brandon Holley

Re: pic: We got bored :)

I believe the orange colored urethane from banebots signifies a shore 30A durometer.

//its shore 40A see below

18-08-2009 18:38

Aren_Hill

Re: pic: We got bored :)

probably around 80lbs of weight on module, cordless drill powering it

Held the setup still and spun the wheel on carpet seeing how the wheels would handle it
after around 2 seconds stopped and this is the result

18-08-2009 21:20

Fe_Will

Re: pic: We got bored :)

"Black PP Core, Medium Orange 40 Shore A TPR Tread" From the BaneBots website.

18-08-2009 22:56

sanddrag

Re: pic: We got bored :)

I wonder if the Blue 50 Shore A would do any better. Also, isn't 80 pounds a but much for one module?

18-08-2009 23:01

Aren_Hill

Re: pic: We got bored :)

Yeah it is, but even then seeing it die in this fashion convinced us to no longer mess with the banebots wheels.
Kinda a safety factor test and they failed

18-08-2009 23:10

Akash Rastogi

Re: pic: We got bored :)

Which Colson wheel do you plan on trying out?

18-08-2009 23:15

Aren_Hill

Re: pic: We got bored :)

2"dia by 7/8" wide colsons

19-08-2009 02:25

M. Mellott

Re: pic: We got bored :)

Thanks to all the folks from 1625 for showing everyone these pictures. Each new image brings new and "wonderful" surprises - I love it!!

21-08-2009 19:05

Dillon Carey

Re: pic: We got bored :)

Its not last years swerve module, its one of the original prototype tubes.

06-09-2009 13:12

Shelabot

Re: pic: We got bored :)

WOW! How practical would that be? Considering the wheels shred easily... How did you guys get the chain length right on?

(From what I can see the 25 chain look pretty taught...)

06-09-2009 13:22

EricH

Re: pic: We got bored :)

It's not terribly hard to do if you have CAD. You can find the size of a link pretty easily, giving you a unit that we'll call one link. You find the exact wrap around the sprockets, which gives you a certain distance (x links, we'll call it). Then you find the exact distance between the wraps on both sides and get another distance (y links). Add x and y and you get the number of links needed. If there is a fraction less than 0.5, add a half-link (special link); if there is a fraction between 0.5 and 1.0, add one link. Make your chain that number of links long, put it on, and you shouldn't have to worry about tensioning for a while.

06-09-2009 14:18

Dillon Carey

Re: pic: We got bored :)

We are currently working on a different setup incorperating colson wheels http://www.robotmarketplace.com/prod...on_wheels.html. The reason we originally went with the banebots wheels is because they come with a half inch hex in them.

08-12-2009 10:30

JesseK

Re: pic: We got bored :)

Any updates? I think it'd be cool to see these orange-anodized ...

08-12-2009 12:33

Aren_Hill

Re: pic: We got bored :)

The place nearby us that anodizes stuff cant do orange sadly

08-12-2009 22:34

Dillon Carey

Re: pic: We got bored :)

We have been working with colson wheels, and they seem to be doing pretty well.

15-12-2009 00:10

Dillon Carey

Re: pic: We got bored :)

I have found a con to small wheels, I lost one...

15-12-2009 00:11

Chris is me

Re: pic: We got bored :)

Post a picture of the wheel (say, in a module) and I'll help look for it.