I want to start with attributions to the inspiration of this extruder to keesj for http://www.thingiverse.com/thing:181833. This is a major work in progress. Plunger style paste extruder. I thought I would throw this on here and see if anyone else wants to play. The tolerances of the parts are very close. Requires a well calibrated machine. Designed to fit a 10cc syringe, future plans for bigger capacity. The plunger mechanism is designed to hold the injection molded printrbot extruder gears. I have not had time to test the torque. I will update when I figure this out.