Other handed direct drive 1.75mm bowden extruder. Also use for cord drive of curtains.

My second version direct drive extruder, I got the handedness incorrect for my mounting on my first one. This version has a funnel in the arm that you can fit a small sponge or cloth in to clean the filament as it goes in. I also curved the bearing end of the arm slightly to allow it to grip even tighter. If you use nylon filament and a good stiff spring it can drive curtains.
Quietly.

Parts:
http://hobbyking.com/hobbyking/store/__10201__HK_500GT_Ball_Bearing_9_x_4_x_4mm_Align_part_H60103_.