Geared Nema 11 Extruder 1.75 mm J-Head

This is a remix of Wild Bill's PG35l extruder design. I really like the extruder design, but I had problems with the PG35l motor. I wanted to adapt the design to use a geared nema 11 motor. So for works pretty great and the retraction is great at high acceleration. Utilizes a 27:1 ratio motor from phidgets.com here: http://www.phidgets.com/products.php?category=23&product_id=3321_0.
The idler is the same as the one in Wild Bill's design. If you have any questions please let me know. This extruder utilizes the hot end fan mount designed by Mike P. for his Delta-Pi printer: http://www.thingiverse.com/thing:53708