[ Don Teach wrote in 211221 MMDigest:

> The shaft will be pulled up when the motor is energized and drops
> when the power is turned off. This means the shaft [rotor] is acting
> like a small hammer each time it comes down.

There's a Facebook group for folks who rebuild antique electric motors
just for the fun of it: https://www.facebook.com/groups/553099208373671/ 

Maybe someone there has the perfect answer for Don Teach?

Gordon Stelter
Athens, Georgia