pic: Jester Drive:Mecanum Wheel Drive Train

[Alex357]

Originally Posted by BrianBSL

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.

It's not coefficient of friction... sorry i hadn't had coffee yet. The 50% figure comes straight from the studies Airtrax performed. It's that the single roller model has 50% less release of friction. The two roller model has two independent rollers, meaning that either side can move either forward or backward, so one could be spinning in a different direction than the other allowing for more release of friction.
The one roller design does not limit pushing power, but it draws more juice to get the same pushing power as the two-wheeled design.