Belt tensioner for Printrbot Simple 1405

** Update Dec 29, 2015 - Finally installed this on my machine and it seems to be working well. So far I haven't had any issues when homing the Y-axis.

Piece that is used to adjust the Y-axis tension belt on the Printrbot Simple Makers Kit (1405)

This part was designed so that you wouldn't need to hold the nut while adjusting the tension of belt for the Y-axis.

I think it makes more sense for the bulkier side to be closest to the hotend/extruder. One side was made thicker to try and pr