[philso]

If conductive metal dust gets into the motor controllers of any type, it could cause the "shorts" between different points in the circuitry controlling the output MOSFETS. This would cause the controller to operate in a way it was never intended to resulting in damage. At work, our production staff blow out and vacuum the equipment they are assembling (large 3-phase motor controllers) before they are sent to be tested.

I saw another thread where people were reporting that pushing the robot, with the power turned off, will cause the motors to act as a generator and damage the controller.