Heavy Duty 1.75mm Bowden Extruder

A 1.75mm bowden extruder which is much less flimsy than others I could find.
It has a 9.8mm hole outlet for an E3D bowden connector (http://e3d-online.com/Mechanical/Bowden/Threaded-Bowden-Coupling-1.75mm-Filament). I tapped mine with a 1/8" tap.
Uses a 608zz bearing for the idler and 2 spring bolts for tensioning.
The hobbed bolt it an Mk8 bolt.
The STL file has supports already, see instructions for more info.