Bowden Cable Holder for RepRap

Obsolete, an updated version is here: http://www.thingiverse.com/thing:1899
It uses a better technique (thanks to profounddevices). See the picture with the bright yellow post it on it... ( also here: http://www.thingiverse.com/derivative:1634 ). You can screw a nut onto the PTFE, which creates a very good connection. The extruder drive mechanism and/or hot end have to be designed with a T-slot to fit this Bowden cable.

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Here's a video of it being printed: (first iteration, a bit coarse quality since I reduced backlash in my Darwin frame while I forgot to reduce it in my software backlash compensation algorithm)
http://www.youtube.com/watch?v=5ddmB9ScSbQ

This is a holder for a 4.67 mm PTFE cable that serves as a guide for the filament. The plastic feedstock will travel from a driving mechanism to the extrusion head, through this flexible tube. The PTFE, a.k.a. Teflon, a very low friction. This solution will allow you to have multiple extruders on your machine wit