[sanddrag]

First of all, the motor will not support the stage. Something else will have to. I know casters suck but for this application several of them all over may be the way to go; with a large axle sort of something for the center of the circle. Excatly how much is this going to weigh when it's built and people and stuff are on it? Also, how big will it be? If it only needs to go one way, you can probably pick up a large AC motor at some sort of surplus store. It shouldn't be too hard to find one with a standard keyed output shaft. Something like this maybe http://www.harborfreight.com/cpi/cta...emnumber=30188 You can also search harborfreight for "motor" and see the other ones. You will have to gear it down quite a ways.