Anet A6 Y Axis Belt Tensioner and Belt Holder

I was using https://www.thingiverse.com/thing:1959208 until the frames broke - the use of a nut makes them too weak to actually last any length of time

Taking lessons learned from the failures of the one above, I designed my own with the following improvements:
* The area where the bearings mount have a standoff so that the bearings can rotate freely
* The frames have a nut trap on one frame and a counterbore on the other so an M3 cap head screw can be used to mount the bearings
* The fram