#1156 new wheels

http://members.lycos.co.uk/wormsterminator/roda.jpg

Oooh cool! Have you hooked them up yet? It’d be interesting to know how well they run. These look custom made; was it difficult?

Yes… they’re custom made, but’s a little hard to do, and we’re already in test phasis.

How are the little tiny axles for the rollers held in?

nice rollers!

how well is that key slot going to hold up? It looks like you guys sandwiched the rollers in between 2 plates… sweet!

where did you get the rollers?

i bet they cut some delrin (sp?) down to size… delrin, mmm, i love that stuff- so easy to lathe and so efficient

Very Nice Job, looks like they will work great

Very nice. We have omni-wheels like those. They were made for us at the great people at Water Jet Controls.

Were you planning on putting any material to those rollers so you can get more forward/backwards traction with the carpet? In my oppionion omni’s are great if you can make a nice balance between traction on the carpet and still being able to slide sideways. We had thought of omni wheels before on my old team but couldn’t find a simple enough way for us to power them well and gain some traction with them. We had pretty much what you posted as they are and then we decided it was just wasn’t worth the added weight with little traction gain so we put teflon skids instead. (263, 2001-2003’s robots)
They are none the less very nicely done. I would suggest going with some added traction device on the rollers if possible, but either way you do achieve the nice turning bonus of the omni wheel design.

In an effort not to sound stale but unable to think of a way not to… You could look at the technokats omni, or trickwheel whitepaper. http://www.chiefdelphi.com/forums/papers.php?s=&action=single&paperid=226
Its a very good example of one way to add traction to the omni wheels while still being able to turn great. Personally I have driven the ball drive robot these were on last year and they worked very nicely.

Just as a heads up: if those plates are made out of aluminum, you may run into distortion in the keyway after repeated use. We had a similar problem on the hub of a large sprocket we were using on our arm this year, and we replaced it with steel after noticing it was enlarging. You may want to explore this a bit more when you start driving.

Overall, a FINE looking design! :slight_smile:

Matt

We were able to accomplish an omni-wheel-like effect today without the use of omnis. It’s so good, I can’t really say yet how we did it. What I can say is that we maintain fairly good forward traction while suberbely reducing sideways traction.

let me guess, wrap it in something? There are a couple of good materials that we have tried, also…

Sounds like a large nylon/delrin wheel with slots cut into the edges.

Forward traction is good because the slots in the nylon dig in;
Side traction is near zero because the nylon/delrin slides on the carpet.

Am I close?

Brandon Heller
Team 931 Mentor
Team 449 Alum

Yes, you are right.

It was hard to do, and it only took 1 and a half days…

We’ve already tested it, and it’s perfect. In the hard floor it “jumps” a little, but in the carpet they are smooth.

There are two aluminum plates on each wheel, grabing the rollers. The total weight of each wheel is 3,7 pounds, and (guessing) each plate is 1/2’’ thick. Do you think we may experience problems even so?

Very nice.

reminds me of ours. I personally took a great part in their manufacture. I am very proud. Ours are doubled up but ofset so they run real smooth. But to keep the weight down we had to cut the inard aluminuim down. We overdid it. We were testing the robot without our bumper, hit a the stairs and bend !!! :ahh: They were easy to fix. :stuck_out_tongue:

Man i love those wheels.

to see them go to www.robomo.com/FIRST

there is no finished photo but u get the idea.