This is my Y-Axis belt tensioner for the Creality CR-10 3D printer. It replaces the 3D printed idler that holds the Y-axis in place on the machine.
I took inspiration from other belt tensioners on thingiverse, namely idig3d's "Tronxy X3 x-belt tensioner" (Thing:2020468). The knob used here is idig3d's knob, not mine.
You will need one M5x25 bolt and a match nut (hex head is recommended for the screw)
UPDATE 03/13/17: Re-uploaded the stl's in "ready to print" orientation.
UPDATE 03/28/17: Uploaded both STEP and Fusion360 achrive files for those who wish to build off this design.