Direct-drive extruder ("KISS extruder" from reprap.me) modified for dual exstrusion.
This is an experimental version and dual extrusion have not been tested - primarily because I couldnt fit the two J-heads close enough to each other, so it is used as a single ended extruder for now...
OpenSCAD file provided for experimentalists
For more info on this project, see http://labitat.dk/wiki/MAXbot
Infill: ~ 20% (works for me)
Required for operation:
Drive gear: MK7
Ball bearing: 624ZZ
Screws: M4x20 + 4 pcs. of M3x20
Small cable tie
1 - Slice and print KISS_dualstruder.stl
2 - Clean out any defects and excess material
3 - Insert bearing into sleve
4 - Insert M4 screw through oval hole to lock bearing in place
5 - Check that bearing can spin freely inside the sleve. If not, revert to step 2
6 - Mount drive gear so that hobbed groove align with filament path 7 - Attach motor using the M3 screws
8 - Install onto your new MAXbot using the kJ.stl adapter plate (this requires two M3x35 (or longer) to lock the J-Head in place)
9 - Attach to MAXbot X-carriage using two sets of M3x30 + nut
10 - Test it!
OPTIONAL: attach cable tie around M4 and motor axis to enhance filament grip (dont overtighten it)