pic: Jester Drive:Mecanum Wheel Drive Train

[BrianBSL]

Originally Posted by Alex357

The one roller vs. two roller difference is indeed significant. Two rollers allow for more controlled motion because of better release of friction. One roller wheels have a 50% higher coefficient of friction causing for more draw and no extra pushing power for the cost.

We haven't done any tests on the two roller model, as we decided that the machining difficulty for the hub was be far too great and supporting the rollers from only the middle would be difficult. I highly doubt that it is a 50% higher coefficient of friction - the only way it would hurt you is if one roller was going to be spinning at a significantly different speeds. I'm no ME (I'm an EE), but doesn't the coefficient of friction deal with the actual force you apply to the ground, meaning you would actually have more pushing power? I agree that the two roller design is better, obviously Airtrax had a reason for using it, but I think you are blowing it out of proportion a bit. The single roller design is much easier to manufacture, although it is more parts. (The hub is simply a piece of square 3x3 aluminum stock with the corners cut off). We had absolutely no issues with pushing power.