Steel Ball Fidget Spinner

thingiverse

This design is optimized for 5/8" steel balls that pressure-fit snugly into the outer holes. The center features an R188 bearing for top-notch performance; with it, I managed to get this spinner spinning for an impressive 3:25. Depending on your printer's tolerance, you can either press the caps together or glue them using a small amount of CA adhesive, as there is only about a 3mm overlap between the male and female parts. The steel balls are quite heavy, giving this spinner significant rotational inertia and making it a high-performance model that's an absolute blast to use!