pic: Plywood 8WD Concept

[s_forbes]

Originally Posted by AdamHeard

2x stall (as that's what occurs when you give full voltage and the motor is at free speed in the wrong direction, the back EMF of the motor is going the "wrong" way and adds to the supply voltage so you get double voltage, double current, double torque).

This doesn't sound quite right... you see max current and torque at a stall condition (motor speed = 0 rad/s). Torque at free speed of a DC motor should be ~0. Are there by chance any experiments that confirm this is the case, or theory to back it up? Where's Ether?

I would expect to see very little torque on a motor pinion if the robot is going full speed and full voltage in the opposite direction was applied. Although, I've been wrong many times before...