The first print profile is for spinner and squishy ball. The bearing is R188 which has dimensions of 12.7 x 6.35 x 4.7 mm. If you want to use another type of bearing, add a negative shape that is equal to the outer diameter of the bearing and add a positive to the batman piece which would be equal to the inner diameter of the bearing. This model is much optimized, to obtain a spin of over 2 minutes, i made hexagon shapes to have less pressure on the bearing. 

[https://a.aliexpress.com/_EvykBfs](https://a.aliexpress.com/_EvykBfs)   Link for ballbearings.