I was using my Wizard (rotary tool) today with a grinding stone on a metal railing and I sheared something inside of it. The motor still runs but you can grab the stone and it will easily stop in your hand even with the motor whirring at full speed. Ever the optimist, I guess the good news is that it means a trip to Harbor Freight to replace it. It was at least 8 years old, so I cant complain too much I suppose.