This is a similar design to my slide/rotate fidget.  Inner ring is stationary on the finger and the outer ring spins easily.  2 sizes (US sizes 6.5 & 8.5) uploaded.  I don't know how these would scale for other ring sizes as the gap between inner and outer ring doesn't really want to be scaled.  If anyone is interested, I can upload other sizes.

I printed with rafts, but I don't know if that's necessary.