I was surprised to find that there was not a nice slew drive design on Thingiverse so I made one. It's completely* parametric so you can integrate it into your projects. It's perfect for moving a large load around (for example a telescope or solar panel) with a deep reduction ratio. A NEMA 17 stepper should generate significant torque using this. It uses 6mm BBs for rolling elements

The STL files are for a randomly chosen 100mm gear. You can adjust this for your own needs. Change the gear ratio (This will require tweaking my gear tooth profiling).

Updated in V2, easier to print with less support. Bearing races no longer need support. Stepper mount plate prints as a separate part to be screwed or glued on.

*Parametric but you might need to tune it a little.

PLEASE REMIX. I'd love to see this get more advanced features like an hourglass worm.

https://en.wikipedia.org/wiki/Slewing_drive