Simple, No frills, motorised turntable built from two nema 17 motors. I took one motor apart and removed the magnets from the shaft to eliminate the cogging effect, this motor then just becomes a rotating shaft for the turn table platform. The second motor drives the table through a popular GT2-200 closed belt, the pulley on the drive motor 16 tooth pulley, very popular in 3D printers. Controlled by an Arduino it offers a wide range of uses. Lots of tutorials on how to drive stepper motors on the web.
Any problems or questions just ask away.