[bheller]

Originally Posted by Yan Wang

Lol, that's the exact same dimensions of ours...

We used Lexan instead of Aluminum, but we did use 60A urethane just like you.

Here's the pic/thread: http://www.chiefdelphi.com/forums/sh...03+omniwhee l

I see. The main differences between our designs is that mine uses an external milled slot (like 45) for the axles, so that we can remove any wheel without taking the wheel apart, and has two rows of rollers.

I did most of the urethane work. If you set up a jig, you can cut very accurate rollers. The stuff is so flexible that the cutting edge of a drill bit tends not to bite in. The holes we drilled with a .1875 drill bit actually came out more like .16. That's a lot of stretch! Originally the plan was to CNC the urethane to an exact profile. Liquid Nitrogen can be used to chill urethane to the point that it acts like a much harder-durometer urethane. I was all set to use that, but then the urethane arrived and we realized it was so flexible that the weight of the robot would compress it to a nearly circular profile.