Re: Turntable Product Purchasing Advice
A stepper motor will allow you to control the turntable "open loop", meaning you just tell the motor to move so many steps and don't bother to measure the actual position of the turntable.
As for running the turntable directly from the motor's shaft, I think you'll probably run into some power and/or torque issues. Those are hard to characterize since they depend on how smoothly the bearings run, where you place the load on the turntable, how large the turntable is, etc.
IMO, you'd be better off using a belt drive to reduce the motion but increase the torque. There are 72 5-degree steps per circle, so one solution would be to have a two-belt system where the stepper motor has a 1" wheel on the stepper motor's shaft, a shaft with a 6" wheel and a second 1" wheel, and a second 6" wheel that drives your turntable. Arrange the belts so each of the 1" wheels drives a 6" wheel, and you'll get a 36:1 motion reduction and a 36:1 increase in torque. For each half-turn of the servo's shaft (180 degrees), the intermediate shaft will turn 30 degrees (1/6th of 180) and the turntable will turn 5 degrees (1/6th of 30).
You can vary the wheel ratios for other values, but that's the general idea.
When you void a product warranty, you give up your right to sue the manufacturer if something goes wrong and accept full responsibility for whatever happens next. And then you truly own the product.