Mecanum Differential Drive

[efoote868]

Originally Posted by Oblarg

Acceleration in FRC (with the exception of 2009's wonky drive surface/wheels) has never been traction-limited, so this is purely a function of the gear ratio people are using on their drives. There's nothing about a shifter which would provide any significant benefit to a mecanum bot; a well-designed mecanum drive is geared for high-speed at all times, because the ability to push is something you've already compromised on.

A well designed two speed gearbox has a significant advantage in acceleration. DC Motor power is on a curve, and the well designed gearbox will keep the motor close to peak power. Without a shifting gearbox, 16 fps in FRC provides nearly no advantage to 12 fps or 8 fps.

Originally Posted by Oblarg

Your setup adds two gearboxes and two motors to the assembly, but I don't see how you get a significant benefit in return. When moving forward, you'd still have two CIMS pushing each side (as the auxiliary motors won't be doing anything, if I understand correctly), so you don't have any more effective, power-wise, than the standard setup.

No, the auxiliary motors would be used in this setup as well. In the picture presented, 8 motors would be driving this robot when it is going full forward. Alternatively, 1 motor could be in gearbox A, which would allow for 6 motors driving full forward in mecanum drive.

The alternative configuration is that planetary gearbox C does not have an auxiliary motor, which would mean that only 4 motors are driving forward.