CL-260 Carriage

This is a replacement carriage for the CL-260 3d printer. It uses 12mm OD bearings from McMaster rather than the stock 11mm OD bearings that came with the original part (which I couldn't find easily). The bearings are kind of short, so I used 2 per axis (4 total).

These are the bearings I used:
https://www.mcmaster.com/#6658k68/=15xyrzg

I the first version of this carriage I had problems with my print splitting where the setscrews went into to hold the bearings as well as the hole for the screw that secures the hotend stripping out. So for this version I made those holes over sized and placed M3 threaded inserts into them.

The threaded inserts I used were these:
http://www.banggood.com/100pcs-M34mm-H62-Brass-Knurl-Nuts-DIY-Accessories-p-971077.html?p=13251118846620130525

You can probably google the best technique for installing these inserts but the way I do it is:
1. Place the insert onto the tip of a soldering iron
2. Push the insert into the hole in the 3d printed pa