Remixed from http://www.thingiverse.com/thing:15718, no spring required plus better view of the filament.
Print with support or v2 without support.
extruder-reverse.stl | 192.8KB | |
extruder-reverse_v2.stl | 184.1KB | |
extruder.stl | 192.7KB | |
extruder_v2.stl | 184.0KB |