Here is a new design I whipped up last night. It's for a Printrbot Simple bowden! This was specifically designed for the 1405 simple because of the Z rod spacing, but if someone can give me the measurements for the other Simples out there I will happily modify it. These parts should not require any modification to be done to your simple because they use mounting holes that are already there. Please do note that you will need to use the 1405 endstop hot end piece if you use the stock 1405 Y axis homing.
There are only two files, and this uses an M4 nut rather than a pressure fitting (this is my first bowden, I decided to go the cheap way out!)
Here is a quick video of the set up https://www.youtube.com/watch?v=1bnY1_DyWbc
Check out the instructions for more information!
Ok everyone, after some testing I have found that if the extruder is mounted so that it extrudes upwards into the tube, it tends to work a lot better. I made a new part called "Untitled_RANDOMNUMBERS.stl" that mounts the motor facing up. I will leave the horizontal part up too for anyone who wants it.
There are also some secondary pieces that mount over the secondary nuts on the PTFE, they double down on the pressure to avoid the tube from popping out. They are entirely optional but recommended.
The parts list below is for the minimum setup, meaning without the extra pieces. If anyone has a question just ask!
Note: This is a WIP, while I have printed the parts and they ARE working great, I will continue to update it until it works perfectly!
2mm ID 4mm OD PTFE tube (varying length). I got mine from Amazon
4x M4 hex nuts
Various M3 screws and 3 M3 nuts (will know size once I get into the install)
Enjoy! For more information on the Bowden extruder using hex nuts, check out the reprap wiki here: http://reprap.org/wiki/Erik's_Bowden_Extruder