Mirrored Gear for Infill 3D's Bowden Geared Extruder

I mirrored the small gear from the 3D infill bowden extruder to be able mount it on a flat surface of the stepper motor axis. Now I can even use longer M3x10 screws with my favorite heads.

I did not design the gear itself, I just mirrored it. Original file by Infill 3D found at thingy [#56679](http://www.thingiverse.com/thing:56679)