Printrbot Plus 2.1 Robust Y Tensioner Assembly

As you can see in one of the pics, my little slab of laser cut wood meant to tension the Y axis on my P+ 2.1 was taking a beating, what with a single screw, two dovetails, and a prayer holding it to the upper platform.

The wood was starting to give way, so I redesigned a printable version that was thick enough to butt up against the back plate of the tray. I also thickened the belt holder and made nut holders to stop them from spinning around when I try to tighten things up.