This is a second take on my previously published extruder design. Although Mk1 worked very well it was a pain to change filament as the tension on the drive was not easy to release.
This overcomes that problem, although the construction is a little more complicated, so I have also made a video. Again, the parts from the original direct drive can be re-used, but if you are making for anything other than a Fabrikator or are making a dual extruder, then you will need to source the following parts for each extruder;
13mm OD 5mm ID bearing with washers of similar dimension
2 m3 x 20 bolts
3 m3 x 10 bolts
14mm Hobbed pulley
2 m5 x 20 bolts
You might like to replace the plastic bowden feed supplied wit the E3D stuff with a good quality brass unit as described in my video.
Build instructions are here https://youtu.be/AGaviHf-3Y8
I used PET filament. ABS would be good. I havnt tried PLA on this one but it should be okay.