I like a lot of tension on my Y belt, and I was worried that only having one side of the NEMA motor shaft supported could cause damage over time. So, this is an attempt at reinforcing that shaft by adding a bearing on the other side. This requires a single 605ZZ 5x14x5 5mm/14mm/5mm 605Z Miniature Ball Deep Groove Radial Ball Bearings, though you can add two of them if you have a particularily long motor shaft.Print it out, and stick the bearing in place. If you have a particularily short shaft, you may need to trim either the motor mount or the back of the support itself slightly for clearance. This will only work with the allignment of http://www.thingiverse.com/thing:221557 as far as I know.