The grinder I picked up wasn't quite as good of a deal as I thought. Turns out the motor is not tefc and its starting to make noise. Its also 3600 rpm, I believe this grinder was designed for a 1740 rpm motor. I’m shopping for a new motor and trying to decide if its worth the $ to upgrade to variable speed motor. I think I can get a 3 phase motor for about the same price so the extra cost would be the speed control and pulleys. I’m thinking the 3 speed is all I need, but I would appreciate your opinions.