Anet A8 back brace

A remix of thingiverse part 2083254. That version with the holes in the base is far too wobbly vertically, and the motor mount printed on the hole bends far too easily from y axis belt tension. I'm also not a fan of vertically printed round holes. But I am a fan of moving the tension forces out to the threaded rods which completely eliminate using acrylic frame pieces for support.

This version adds a vertical brace to the motor mount, and changes the motor pulley hole to a hexagon, which p