Inspired by the inner workings of a ball bearing, a fidget ring has been created that invites play, soothes and awakens creativity.
The ring shown has ring size 58 (circumference) and is 10.5mm wide. The 22 balls have a diameter of 5mm. The rail in which the balls lie is 9.5mm wide and 3mm thick. The space between the balls and the rail is 0.1mm. On my fdm printer the balls remained movable. I printed with 0.2 nozzle and a layer thickness of 0.1mm. Since the balls will move differently depending on the tolerances of the printing process, it may be that the ring sits a little wider or tighter than you expected. However, the ring is more forgiving of too tight because the balls allow it to slide over the knuckle much more easily than a ring of comparable size.
Since you can't scale the ring arbitrarily if you want to keep the clearance constant, I exported the ring in several sizes (stl only). This changes the number of balls and the circumference of the ring. The diameter of the balls and the profile of the rail remain the same.
As a trained goldsmith with years of experience in 3D design, I work with great care. If something does not fit, please feel free to contact me.
If my designs inspire you contact me for your personal ideas.