This is a derivate of Jonas Kuehling's excellent "Greg's Wade reloaded - Guidler, Tilt Screws, Fishbone Gears"
The .scad file is a "quick and dirty" hack, sorry abount that. The .stl file was rendered for the reprap-fab.org heaterbarrel and a layer_thickness of 0.333mm or 0.25mm. You can change it easily in the .scad file, but you need the module â€œjonaskuehling_default.scadâ€ and â€œconfiguration.scadâ€ from the original page at http://www.thingiverse.com/thing:18379. I will do it for you if you want.
The Extruder is designed for 9:47 gears. "Normal" gears don't fit!
The gears are from HUGO_improved v1.3 http://www.thingiverse.com/thing:22586, an excellent PrintrBot derivate.