this is a remix of thing: 1721049, i edited the extruder to mount it on the AM8. The extruder should work for flexible filaments, I have not tested it myself.
Have fun with it
Adapted for E3D Hobb Goblin 8mm hobbed shaft
Adapted for PC4-M5 bowden connector
Filament path is extended to provide contact with Hobb Goblin 8mm hobbed shaft and 608ZZ skate bearing. This extended path should allow for flexible filaments without the potential for kinking material.
Assembly instructions / Bill of Material : http://reprap.org/wiki/Wade's_Geared_Extruder )
Geeetech Prusa i3 pro b custom
printed with PLA, soon I will print in PETG
Top / buttom: 1mm