Only two parts to print, prints with or without supports. Uses one M4x20mm (or similar) screw to attach the knob. Sized for a regular mouth canning jar, uses the ring from the lid of the jar as threads.
Requires:
Screw threads into the knob though the hole in the back of the base.
Make sure the knob still freely rotates when you install the screw, don't over-tighten or you will jam the knob. The screw should only be threaded in far enough to keep the knob from moving in and out of the base too much.
Prints without supports. Screws in easily and won't come off.

The author remixed this model.
remixed model