Fancy Schmancy Wheels

I’ve been playing around with Inventor over the last two weeks while simultaneously experimenting with some more unique ideas for drivetrains. Thus far, I’ve been using Ed Sparks’ models of the 8" diameter wheelchair wheels, but I don’t like the solutions I’ve found for mating them with sprockets. Also, I wouldn’t mind something with a bit better traction.

So, I thought that we could design and build our own wheels this season - as I’ve seen lots of other teams do this. My question, though, is how do you do it?

http://www.theforumisdown.com/uploadfiles/1102/bling_bling.jpg
(You may have to copy and paste.)

This is what I had in mind, and I’ll add Brecoflex belting to the outside, in theory.

But, how would I make it? What machinery would we use? It looks like we’ll have access to anything I can imagine this season, including several CNC mills, CNC lathes, CNC punches and CNC sheet metal bender-things.

Any ideas? Some help? My bling-bling quotient is severely lacking.

The link is a no go for click or copy paste.

Also, according to my understanding of last years rules, you could not have machined wheels larger than 6". Stock that large is not nearly allowed by the additional hardware list and 6" is the biggest Small Parts carries.

Check out 122’s wheels from last year, they were almost exactly like that and fairly large…

in past years we have done everything from cutting off the rubber from the wheelchair wheels and adding new traction to making our own wheels our of wooden circles (aka: last years)…take a look in the gallery for ours…

http://www.theforumisdown.com/uploadfiles/1102/bling_bling.jpg

Copy and Paste that

Not bad at all. I would have the wheels wider though.

Also, can someone tell me how a custom machined wheel larger than 6" is (was) allowed?

*Originally posted by sanddrag *
**Not bad at all. I would have the wheels wider though.

Also, can someone tell me how a custom machined wheel larger than 6" is (was) allowed? **

Well, that’s just one wheel. There would be 4 per side, in theory.

If you were able to get stock that large. . .or, even 6". . .how would you machine it to get that sort of object?

*Originally posted by M. Krass *
**Well, that’s just one wheel. There would be 4 per side, in theory.

If you were able to get stock that large. . .or, even 6". . .how would you machine it to get that sort of object? **

We did something exactly like that last year. The wheels were machined with an automated mill at our high school I believe. In fact, the wheels got messed up so they had to machine some new ones this past weekend.

The problem with the bicroflex is adhering the stuff to the wheel. We did have a compound that adhered it rather well. We were using the green bicroflex belts, but they didn’t offer enough traction, so we went to the brown bicroflex at the cometitions. We attached this to the wheels by drilling holes in them and riveting the belt to the wheel. It worked, but eventually the belting wore down and had to be replaced (which is why new ones were machined).

I know we had CAD drawings on our team’s website, Team 93, but they don’t seem to be there. Check back some time and the cad drawing should be there.

You can see the brown belt on the right (rear) wheels, and the green belt on the left (front) wheels.

toborv.jpg


toborv.jpg

crap the pic isnt on this computer, ill update it later

BAd

*Originally posted by sanddrag *
**Also, can someone tell me how a custom machined wheel larger than 6" is (was) allowed? **

As long as you can make it out of allowed raw materials, and it doesn’t violate any of the other rules(no razor spikes for traction due to carpet damage, etc), you could have wheels as big as you wanted…

*Originally posted by Nate Smith *
**As long as you can make it out of allowed raw materials, and it doesn’t violate any of the other rules(no razor spikes for traction due to carpet damage, etc), you could have wheels as big as you wanted… **

The biggest metal shaft allowed was 1 or 1 1/2 in. The biggest aluminum extrusion allowed was 2x3 cross section. The thickest plate allowed was 1/4. None of these would really be useful in making wheels. All the wheels I saw were much larger than the allowable stock. Also, wheels could only come from skyway or be a caster. Was there special permission given in a team update or e-mail?

Small Parts has (had?) 6" round stock aluminum.

Andy B.

*Originally posted by sanddrag *
The biggest metal shaft allowed was 1 or 1 1/2 in. The biggest aluminum extrusion allowed was 2x3 cross section. The thickest plate allowed was 1/4. None of these would really be useful in making wheels. All the wheels I saw were much larger than the allowable stock. Also, wheels could only come from skyway or be a caster.

You could always take a few plates, cut them to size, and fasten them together somehow…or use the stock from SPI that Andy mentioned…

Keep in mind also that the wheels only coming from Skyway or being a caster only applies to pre-fabricated wheels…if you use raw stock, you can make anything you want(except things like springs, which are specifically disallowed.)

hey,

last year our team made some pimpin wheels, u mighta seen TheWheelMan pushing our wheels in the pits last year…

What we did…

took 6" blanks of round stock…
hogged out the inside to the our drawings,
made a set of soft jaw chuck for our prototrac,
made a bolt hole pattern, and drilled a hole in the center of where our spokes were,
ran the prototrac to cut out all of the spokes.

then we went to the turret lathe, and made a series of grooves and vees on the face to provide traction without damaging the carpet.

wanna pic? here ya go!(it in a post of mine)

Bad%between%

Who ever went to GLR knows who had the “Pimp” wheels. HOT BOT!.. Their spokes where flames and chromed out! Now that was “Pimpin’ It” :smiley:

Hot Bot 2001 & 2002 made their wheels by cutting the center plate with the flames and bolt pattern out of what looked like 1/4" aluminum, then wrapped aluminum around the circumference to add width and welded the two together and then added traction material. It was very effective.

Someone from Hot Bot can probably fill you in with pics. Other than that 6" Aluminum Round Stock was the largest you could use to make ‘billet’ rims for your bot.

*Originally posted by Matt Reiland *
**Hot Bot 2001 & 2002 made their wheels by cutting the center plate with the flames and bolt pattern out of what looked like 1/4" aluminum, then wrapped aluminum around the circumference to add width and welded the two together and then added traction material. It was very effective.

Someone from Hot Bot can probably fill you in with pics. Other than that 6" Aluminum Round Stock was the largest you could use to make ‘billet’ rims for your bot. **

Or if you look in the gallery you’ll come up with this:

*Originally posted by Jnadke *
**Or if you look in the gallery you’ll come up with this:
**

If anyone from 67 is reading, I’d like to know more about how about you made those beasts :slight_smile:

As of now, I’m considering reducing their width to 1/2" and making them from one sheet of aluminum and one sheet of polycarbonate bolted together. . .or, some variant of that.

*Originally posted by badjokeguy *
[Blast year our team made some pimpin wheels[/b]

Yup, those sure are pretty wheels. Great example of HSers making something truly beautiful.

But…
You guys talk about these things like they are the greatest things. I’ve heard they weren’t all that great for pushing. Did you ever calculate a coefficient of friction value for them? I’m curious. I know for a fact that the “team60” tread is better, and brecoflex is even better than that…

Calculate it, and let me know.

*Originally posted by M. Krass *
**If anyone from 67 is reading, I’d like to know more about how about you made those beasts :slight_smile:

As of now, I’m considering reducing their width to 1/2" and making them from one sheet of aluminum and one sheet of polycarbonate bolted together. . .or, some variant of that. **

Actually, those wheels were made by team 263. I dunno if they are more than 6 inches in diameter, but they look like it in the picture. They definately look like they were made how Reiland said. If you look at the inside of the wheel on the left, you can see a separation between the plates on the wheel. Looks like they just took aluminum plates, and heated them up with a torch (which tends to make aluminum more maleable). Then they formed them and held them together by welding spokes on. I could be wrong though.

Some more wheels:

401: Picture 1 Picture 2

535: Picture 1

263 (another picture): Picture 1

188 (these guys could pull a lot): Picture 1 Picture 2

522: Picture 1 Picture 2

58: Picture 1

67 (man that’s a big wheel): Picture 1

353: Picture 1

Team 357 created these wheels for use with the 2002 Jester. The wheels provided excellent traction for pushing and resisting lateral motion, however, the wide, flat profile of the wheels meant that turning was only possible in low gear. When the Jester was in high gear the motors tended to stall. The wheels were strong and good looking but…the wheels required a great deal of machining time and may not have been a good use of valuable and limited build time.

wheels2.jpg


wheels2.jpg