pic: 148 Follower Wheel Assembly

It looks to me like it’s a 1:1 ratio. Would make programming a bit easier without the extra math to account for the gear ratio.

It’s 1/8" bigger radially. It should be okay, if there are problems during testing I’ll tweak things a bit. We plan to spring load it down. Spring tension, TBD. Surgical tubing, of course.

The electrical engineers on our team say I have an “encoder mental block” where I refuse to model them into the final design. I had a heck of a time cramming them into Tumbleweed last year. This year we knocked em out almost immediately so they’ll keep their mouths shut.

How much would you pay for one? :wink: I’m starting my own company KarthikJohn.

I think with some down-force this should get pretty good grip on the regolith.

Yes, 24DP. We just modded the VEX 60t Gear Model to make the coupler piece. Works pretty well.

The side plates are laser cut ABS, 1/8" thick (cut on our small 12x24" laser, not the big one that does the sheet-metal.) The coupler is 3D printed ABS on our Dimension SST. I feel pretty darn spoiled.

Probably could have gone with a smaller package, but we’ve got plenty of room in the drivetrain to mount it. Like Raul said, if the 60t gear catches some carpet we may change it. I’m not real concerned. Shrug This was done quickly and the design group moved onto other things.


Why not use the larger omni wheel? It would get the wheel away from the gear more. Also the larger omni probably has a less likely chance of slipping…

“Knocked out”…the encoder models or the EE’s? :stuck_out_tongue:

This year the encoder models… but thanks for a good 2010 plan.

Not counting the cost of the encoder, I’d say $25-30 probably.

Ditto on this. With encoder, depends on the accuracy/type of the encoder.

Looks strikingly similar to something we’re making…

Where would you put this company? Halfway between Toronto and Greenville is…I dunno…Kokomo?

With a few modifications you could use the US Digital encoders that come in the kit.

This what we are doing. Not because of the slipping issue, but for “smoothness” of rotation. The large Vex omnis have two sets of rollers, offset to the sides for a smooth roll. The small ones would tend to go bumpity-bump as it transitions between the rollers. We thought the smoothness would be better for the encoders.

Very nice! But why such a big green gear? I’d have used a smaller gear and a similar green gear on the encoder. I am curious

Why gear at all? ours is a direct drive set-up.

Wow, maybe this was NOT worthy of showing off. Sounds like almost every team in FIRST has something “identical” or better back in their shop. Color me corrected.


PS - Of course I was joking about starting my own company and selling these.

John that sounds like a lot of work for you… we all know Karthik isn’t allowed to design anything that would actually go on a robot! :stuck_out_tongue:

Do you want to forge a partnership with CollinChris?

It’s a family business. Right now we have no products, we just intend to steal good ideas from Chief Delphi posts and set up shop. Right now we are producing a cool wheel follower assembly that it appears you have copied… :slight_smile: (our lawers will be contacting you for the patent infringement)

Well, if it makes you feel any better, we don’t have all that fancy-smancy vex stuff, so ours looks gargantuan compared to yours. :smiley:

Just like all the roller claws “identical” to 1114’s last year, right?

Aww. I’m sure this will be the coolest looking follower wheel I’ll see all year, “identical” in function isn’t really identical. Last year we were “identical” in function to 987, but they were clearly better (in design, looks and performance).

Aww. lame. Sometimes we can blinded by awesomeness.

Have you tested to see what percentage of your total robot traction the follower wheel represents? (like the GDC posted)

I am not saying that I think this will represent >5% of robot traction, I would be surprised if it did. I am only curious because my team has yet to test our Way-Better, Uber-Awesome follower wheel we build out of Joe’s spare Vex parts :rolleyes: :smiley:


Are you running any sort of bushing on the vex shaft? Or, are you just letting it ride on the 1/8" hole in the ABS? (I’m having a hard time finding a flanged bushing for an 1/8" shaft)

Very pretty, thanks!