MK7 Extruder Drive

This extruder is a revision of : http://www.thingiverse.com/thing:13727.

The drive lever hole is elongated to keep the threads of the 3mm socketcap bolt from jamming the lever. Both parts have been thickened in the revised areas to prevent warping. The extruder drive in the picture was printed in ABS at 0.1mm layer height on a heated bed. It is mounted on a Hadron Bot frame and has worked reliably with this re-design. This drive uses the makerbot mk7 filament feed gear.

For those of you who are having trouble with PLA jamming with metal heatbreaks, use a little bit of vegetable oil, and smear it on the filament. This will season and coat the steel inside your heat break and create a more slippery surface. This has solved my filament jamming problem all together.
Also use high quality filament with consistent tolerance of diameter.
Use a reliable cooling fan to cool your hot end heat sink and autocalibrate your hotend PID settings to prevent temperature fluctuations.