This (untested) design has 3 printable parts. These can be used to convert a stock qu-bd extruder to use a bowden tube. Note that this is an experiment. I currently do not have any mount for the drive portion, once I get it working I'll work that out. My goal is to get 2 print heads as close as possible mounted on the ord-bot. I believe I can get them closer by removing the drive motors (thus bowden) At the moment i do not believe I can use the body block from the MBE. Those 6mm tapped holes are probably too close together. This first draft is intended to help me debug the whole bowden concept non-printed parts: update 10/9/14 I have been printing with this setup for over a month. I am using the water cooled hot end from thing:280314 instead of this air cooled one, but I would expect similar results. I consider the bowden setup a success (had to increase the retract compared to a virgin MBE to eliminate stringing.) At this point I'm more interested in perfecting the water cooled extruder so I'll post further updates there.