What do you use for wheels?
 

Every year, we get into the situation where we have to choose/design our wheels. We've ended up using highly modified 6" skyway wheels for the last couple of years and are generally happy.

However, we have to double them up to get the width that I like (2") and we have to knock out the bearings and make many other time consuming mods.

We have made polycarbonate wheels, but they have fairly low friction with carpet. We have wrapped wheels in timing belt, which had much better friction characteristics, but tended to de-bond.

I wanted to try knurled aluminum, but last year's rules threw that out.

I like the skyway beak-lok design, but the choices are too big and heavy for my tastes.

So, I wanted to see what other people have used or plan to use for wheels.

Last year we used 4 9" pnematic wheels.

Last year we used 4 of the skyway 9x2 beadloks like in the kit. We drilled them out to save weight and we turned them down to 8.5 in di to have a flat tread profile. While the traction was surprisingly good, the wear characteristics were not.

Next year we hope to go with a pneumatic tire.

we used 8 inch pneumatic wheel chair casters that we bought at a local supplier.

We just use the wheel chair wheels, but i think we may make some custom ones this year.

We designed and made two 9" omniwheels using lexan and urethane as the front wheels. The back wheels were modified kit 9" skyway wheels, treaded.

[edit] This was for last year's robot only. [/edit]

Our wheels change depending on our robot strategy and design. In 1999 and 2000 we used the 8" wheelchair wheels. In 2001 we used the 6" wheelchair wheels. In 2002 we built aluminum wheels that were 5.5" in diameter and 2" wide that we attatched belting material to. In 2003 we built aluminum wheels that were 6" in diameter and 1.25" wide that we attatched belting material to. We'll decide on wheel diameter and width, or tank tread width for 2004 the first week of the build period.

In previous years and the beginning of 2003, we took the 6" skyway wheels, lathed off all the rubber, and epoxyed a strip of some soft rubber tread stuff to the wheel. It gave us great traction. However, this year, when we tried the same thing, we found that our tread was all but gone after one regional, shredded away by the ramp. So we switched to these other, wider, 6" wheels made from smooth neoprene which weighed 2 lbs each (!!!) but gave us awesome traction, even on the HDPE.

Weuse plywood laminated wheels. This allows us to change treads easily if worn out or find some with better traction.

Bricks????
 

Big Mike says you need bricks... Well when you have Gum RUBBER all you need is a 6 inch hole saw!

Refer to this thread:

http://www.chiefdelphi.com/forums/sh...ght=gum+rubber

What belting material? How did you attach? Did you have any problems with either slip or delamination at the join of the belt ends?

Re: Bricks????
 

These wheels look really cool. Where did you get the gum rubber? How much did it cost? Were there any problems of tearing at the bolt holes?

Hmmm anyone ever think of casting their own wheels using poly urethane?? People do cast their own wheels for sumo robots using this material and it displays great traction. I just received an article on this. Apparently wheel hardness is measured on the Shore A hardness rating. This rating can rage from 10 to 80 where 80 is the hardness of a bowling ball and 10 is soft, gummy material. Though this material has only half the traction of the gum rubber. People also coat the wheels with silicone to improve the wheel's traction. Silicone can be bought at automotive stores. One last note. Generally high traction wheels tends to loose traction as it picks up dust so make sure that you clean it off with baby wipes.
Yeah modifying those tires in any way was a bad idea. My friend said that the synthetic material was not really designed to be modified. We lost our treads in the first run of our match.

We use the Skyway 10 X 3 pneumatics for all four wheels. You can order them with bearings or keyways. They saved us last year when we had too much traction and were stalling motors trying to turn. We ran the pressure up to the specified max to reduce the contact patch and could turn again.