Ball bearing motors

We discuss and clarify a number of very serious mistakes and misunderstandings concerning the mechanism of the ball bearing motor. Specifically we show that Gruenberg's mechanism, which is equivalent to the phenomenological model of Watson, Williams, and Crimp (1993), does not explain the ball bearing motor behavior at all, because the predicted total torque T acting on the ball is T=0. In addition, another wrong conclusion obtained by WWC is their interpretation of their experimental results concerning the relation of speed versus current.