Odie
Micro motors are not air driven. Comes with a transformer with a speed control built in. A power cord runs from the transformer to the micro motor which is like a Dremel like tool but is smaller and lighter and easier to control. Cost is too high if one is only going to fuss around with it though. The one I have has a lot of torque to go along with the speed. Try to find a friend who has one and try it if you can. Air driven grinders reach up to 500,000 rpm now. But the torque is not there and they only handle small bits.
Hugh