I have been using my pneumatic die grinder with 4" buffing wheels to polish the lips of deep dish auto wheels, but the grinder lacks torque. I'm now considering an electric model such as the Metabo GE 700 or Makita GD0800C (7000 rpm and up) or the Metabo GE 900 (2500 - 6000 rpm).
It seems like the GE 900 is what I want in terms or torque, but the max speed is a bit slow for all my 4" wheels. Is 6000 rpm enough to cut and finish polish aluminum wheels with a 4" buff?
Would one of the high speed grinders work out better, assuming I can load them such that the wheel speed drops to what I need? Or would their lower torque output make them a worse choice than the beefy GE 900?
Or is the whole idea of using a variable speed electric die grinder barking up the wrong tree? I have a flex shaft that I run with my drill press motor, but the hand piece gets VERY hot after a few minutes. I bought it from Eastwood many years ago.