I I have modified the authors design to route the belts back out of the mount at 45 degrees away from the bolts so the belts do not need to be modified, keeping the integrity of the belts, making them last longer before they fail. The 45 degree bend also locks the belt so it takes less pressure to secure it when tightening the mounting bolts to reduce the risk of stripping the bearing carrier threads. As a side effect this mount also became 0.02 g lighter and has stronger clamping force.

I recommend printing in ASA.
3 wall loops, and 50% sparse infill.

This will give more than adequate strength for the belts in the clamping region. I have tested the fit with Gates branded 6 mm belts.