QUBD : Bowden extruder with the original drive gear with 3/8' thread push-in connector.

This "thing" uses the original drive gear or "mk7", so that I don't need updating the firmware.

Also, it takes the push-in connector with 3/8" thread. Originally, I used the 6mm, but they are

• Easily clog the filament ( more often than the extruder itself )
• Easy to pull off by itself ( after I screw / unscrew few times )

With this "thing", simply sandwich more tighten if the push-in connector got ever loose, .

I use the arm and idler here.
http://www.thingiverse.com/thing:38281

But I believe the following also work.

http://www.thingiverse.com/thing:15718  http://www.thingiverse.com/thing:21686  http://www.thingiverse.com/thing:43411  http://www.thingiverse.com/thing:53009 ( print reverse )