About this 3D model
Print the side and center of the spinner in different colors.One side of the central part needs to be slightly treated with a sand paper.And just put them together.They keep firmly on the bearings even without glue. But you can add a drop of glue.In scad and stl hole for bearing 22.1mm for snug fit (i am using cura and nozlle 0.3mm). for spinner caps i am used Ultimate Spinner Button Cap Low Profile Roundedby silyavski,http://www.thingiverse.com/thing:2136665scaled 104.5% for good fit and printed with support, cap up.