Quote Originally Posted by irving2008 View Post
Been prevaricating over how to retain bearings in the planet gears The revised gears are 10mm thick and the bearings I'm going with are 3 x 9 x 4. The planet carrier has a 3mm boss and with a 3mm caphead screw as an axle the bearing will be centrally located in the gear against a recess. but that doesn't stop the gear sliding off the bearing. Normally you'd have some sort of bearing retainer but the only way I can see to do this with a 3D printed gear is either a groove 'not printed' to take a circlip which means an overhang (do-able but not ideal) or some sort of printed protrusion which will deform enough to allow the bearing to be pressed into place (is this possible?).

Thoughts?
The bearings should be ok on a press fit but a small ring could be glued in place. I've been using 5 x 11 x 4 bearings for the planet gears and they press in quite firmly.