motoring the wheels

[Jon Stratis]

I would say most teams probably do a chain drive of some sort.

Generally speaking, you probably want all of your wheels powered in some way - it really helps if you're being pushed, or are off balanced when climbing a ramp, or a dozen other situations that can lift one or more wheels off the ground.

Here's our setup for 6-wheel drive in the past (we've used it 3/5 years since the team started. The other two we used a 4 wheel design for Lunacy and Mecanum drive for Breakaway):
- Motors/gearboxes are placed on the rail near the middle wheel
- chains go from the gearbox to the middle wheel to power it
- two more sets of chain go from the middle wheel to the front and back wheels

This way, every chain wraps halfway around each sprocket, which helps prevent jumping your chain off the sprocket.

We've never direct-driven a wheel (where the output shaft from the motor is used as the axle for the wheel) - we feel that the failure modes for that are a little too risky, compared to running a short chain between the motor and the wheel.