3DMON's DD Extruder for the E3D Hotend

Here is my DD (Direct Drive) extruder I designed for the E3D hot end.
Mine is attached to an Ordbot but I included a body for 50mm (Mendel style) mount holes too.
A Jhead hot end should work also but I have not tested that.

The extruder was designed in Sketchup and I have included the .skp and .stl files.

Parts needed:
1- The best hobbed extruder gear out there!
1.75mm gear http://www.ultibots.com/micro-extruder-drive-gear-1-75mm-filament/
or 3mm gear http://www.ultibots.com/micro-extruder-drive-gear-3mm-filament/
4- 3 x 25mm bolts
2- 3 x 20mm bolts (for Ordbot mount)
1- 3 x 10mm bolt (for Ordbot mount)
1- 5 x 10mm bolt (for the bearing)
1- Bearing (625- 2RS or 625zz) 5x16x5
1- Spring 3/8" x 1-1/4" (Mine came from a Home Depot assortment box)
1- Nema 17 Stepper motor