A curiosity:

3D printing is a awesome tool but not everything can came out like it should. Sealed Bearings are tricky pieces and demand precision. On the first axles, used the Dremel to proper seat the pinion bearings but was much of a guesswork.To little and the axles halves doesn't close, too much and the bearing gets loose



Did this improvised cutter with the right diameter and spacing:











Simply fit it and screw the halves while rotating the tool. There's no chance of cutting too much