Our prototype drive chasis(only weighs 27lbs!)

[Ether]

Originally Posted by AdamHeard

I'm missing something, with the omni's at 45* if the wheel diameters are the same and the rpm at the wheel shaft is the same for the both, wouldn't the mecanum be faster?

No. In the forward direction mecanums will go the same speed as a standard wheel (neglecting parasitic losses due to roller axial free play and carpet stretching which causes the rollers to spin). Omni will go sqrt(2) faster due to the 45 degree angle.

See attachment. The blue arrow indicates how far the omni wheel would travel for one rev if not constrained to move in the forward direction. The red arrow indicates the motion contributed by the (spinning) rollers when the wheel is constrained. The black arrow shows the net motion, which is sqrt(2) greater than the length of the blue arrow.