Acrylic Wade's Geared Extruder for QU-BD Hot end.

thingiverse

The QU-BD extruder failed to work for me as I lacked the necessary 624 bearing for bdring's mod or other MK8 minimalistic alternatives. However, my laser cutter served me well until my Solidoodle arrived. After a week spent struggling with the QU-BD stock, I decided it was time to seek an alternative. The extruder functioned smoothly, enabling me to focus on printing rather than machine issues. As an update, PDF, DXF, and DWG files are now available, with instructions mostly within these files. This extruder requires 608 bearings, which are easy to obtain. The original PDF drawing can be found at http://reprap.org/wiki/Wade%27s_Geared_Extruder. If you manage a successful print with your QU-BD, consider trying mods like the one from this link first: http://www.thingiverse.com/thing:43411. It also uses a 608 bearing and is about to be tested by me.