Quote Originally Posted by tonyfoale View Post
SNIP//Many designs rely on putting an out of balance mass on the motor shaft which is easy but I often wonder how long the motor bearings or motor shaft will last under that king of loading.
Not for very long, no... I made a Q 'n D green sand sifter with a salvaged 150W DC motor which held up for abt half an hour before the endbells fatigued into oblivion.

BTW: The Ichiban ("1st" in Japanese) Moto "promo" of mine isn't in any way meant to put your eminent site 2nd!!!