Extruder Merger

thingiverse

New version at https://www.thingiverse.com/thing:2808135. This part lets you use two extruders with one hot end. I've tested it with a Light6 and so far, the concept works well; I just need to fine-tune the g-code to handle excess material left over after switching extruders. You'll need three 1/8 push fittings to connect this part; brass ones thread better for some reason but will require drilling to let the Bowden tube pass through. Search eBay for the part "PC4-01" to get predrilled versions, although they may need heat to thread properly. As for firmware, if you want to use a Ramps board in EFB configuration (Extruder, Fan, Bed), you'll need to adjust the pins.h file; enable the second extruder under the EFB area by replacing -1 with something else and change the thermistor pin for the second extruder to match the first. I've uploaded my configuration for a Ramps 1.4, but use it with caution as everyone's printer is different, so endstops, bed leveling, etc., must be adjusted according to your setup. For g-code, you'll need to retract about 200mm before extruder change and extrude at least that amount after. This is what I have in Cura so far: ;Switch between the current extruder and the next extruder when printing with multiple extruders. ;This code is added before the T(n) G91 ;Relative positioning G1 E-1 F6000 ;Retract filament a bit before lifting nozzle to release some pressure G28 X0 Y0 ;Move X/Y to min endstops, so head is out of the way G90 ;Absolute positioning G92 E0 G1 F10000 E-165 G92 E0 G1 Z+7.00 F{travel_speed} ;Allow room for excess filament to pass And after: ;Switch between the current extruder and the next extruder when printing with multiple extruders. ;This code is added after the T(n) M104 T0 S215 M104 T1 S215 G92 E0 G1 F10000 E195 G92 E0 G1 Z-7.00 F{travel_speed} ;Return to original layer height The speed of retraction is important; too slow will stretch filament in the path without clearing it. Print Settings: Printer Brand: RepRap Printer: i3 Resolution: Any Infill: Above 20% Notes: I printed in PLA and it works so far, but I'd recommend printing in ABS due to heat associated with the process.