Quote:
Originally Posted by Retired Starman
One thing to watch is the construction of your turntable. If you are using one of those light-weight lazy Susan bearings, it will deform under the side stress of a belt or chain drive, and even a drive puck.
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Reading this reminded me of our other turntable, on our air cannon. Since the turret isn't heavy (some sort pipes and the brackets to hold them), we weren't worried about deformation under the torque of rotation. However, because we throw t-shirts and footballs, we were worried about deformation due to lateral forces. After a rather embarrasing amount of mental fiddling with a lot of different things we could purchase to handle the lateral stresses, we finally pulled a toughbox 2 out of the old parts bins and mounted it so the shaft points up. We tie-wrapped a long shaft key at the bottom so we don't lose it as often. The turret is bolted to an AndyMark hub, and we hold the thing down with just a 1/4" thumb screw. This turned out to be really useful when we realized that the new tires made the air cannon wider than any of the doors on our build space - we popped the turret off and carried it out sideways. (We have since slimmed down the base.) Currently we're manually aiming the turret, but we have a mini-CIM and a potentiometer already mounted so we can convert the TB-mini into a servo.