It is still difficult to rotate heavy objects with LEGO and hence I designed an ultra compact LEGO compatible ball bearing. it is only 6 studs wide and two studs high. I also added two lift arms. You can put a worm wheel in there to rotate the turn table. The 3D model is available for download from Autodesk. You may need Fusion 360 to work with the model.
This ball bearing is so small that you need a very high resolution printer to get good results. Some of the wall thicknesses could be to small to get printed on low quality printers. I will now be working on a slightly bigger version that can be printed on more affordable printers.
A technical drawing is available:
LEGO Compatible Compact Ball Bearing Drawing by Christoph Bartneck on Scribd