The problem with drill motors is that they produce almost no torque at their top speed, and they arent the most efficent of motors.

But what about a methanol RC motor? Some do about 40000RPM and peak at almost 2000W yet only weighs about 300 grams each.

Youd normally need some monster gearing to bring that down to a sensible speed, but for a spinning disc?

http://www.osengines.com/engines/osmg2071.htmlhttp://www.osengines.com/engines/osmg2071.html