In Lunacy, we used one of these lazy susan bearings
http://www.leevalley.com/en/wood/pag...50,43298,43316 which are much better quality. We had to make some modifications to it and it did come on the way back to the pit after our first practice match when our bot fell off the wagon. We were able to find most of the ball bearings and put it back together. There's a removable threaded plus which is used to put the balls in. Lesson learned - no running. It supported the weight of our tower, and tiltable 4 wheel shooter. It worked well until late last year when the race finally cracked. We cut a Gates belt apart and epoxied pop-riveted it to the circumference of the lazy susan and then used a window motor to drive it.
http://www.othsrobotics.ca/images/fred.png