why are ball bearings not to be used on motors less than 5.4 amps? Also, since you are so knowledgeable in royals, would you be able to help me finding bearings for my 801? I believe they are getting worn out. lately I can hear sort of a ringing sound from the motor. its very faint, but I know my machine and it wasnt there before. The motor shaft has about 3/16" in-out play in it, which im sure is not great news. But it still works good, just makes me worried. I want to be able to rebuild this motor when the bearings go, so it will be around another 50 years.