Oy... Why oh why is my extruder reversing at the end of the Prime??? When I test the following by selecting the tool manually on the webUI or panel the prime works exactly as I want it to. When I print though instead of giving me a second extrusion at the lower feed rate for 5mm it reverses and goes for a 20mm retraction which ruins everything. ;Prime G92 E0; set position G1 E20 F200; Extrude 20mm G1 F50 ; Set feedrate to 50 G1 E5 F50; Extrude 5mm G1 E-0.05 F200; retract .05mm G92 E0; set position G4 S2; Dwell 2Sec Anybody?
FWIW... I added another set position and it stopped the unwanted retraction: ;Prime G92 E0; set position G1 E20 F200; Extrude 20mm G92 E0; set position G1 E5 F50; Extrude 5mm G1 E-0.05 F200; retract .05mm G92 E0; set position G4 S2; Dwell 2Sec
Keeping it in absolute mode seems prudent given each tool uses this macro and each tool has it's parked location. Resetting the position fixed it.
No, you should always switch to relative mode in any macro that does extrusion. That way you don't mess up the virtual extruder position when the slicer isn't expecting it. When the macro completes, the original absolute/relative setting will be restored. BTW I strongly recommend that you slice models in relative extrusion mode. Handling absolute extrusion mode invokes a lot of extra complexity in the firmware.
Correct me if I am wrong, but I believe you meant to say "No, you should always switch to relative mode in any macro that does extrusion."
You are quite right. I have corrected that post. [BTW is there a strikeout format option in this forum software?]
This is something I've been struggling with too; thank you for the lead! I'll look at my prime scripts today after I get some prints through. I haven't yet done any toolchanging prints because I've had such little faith in the prime (that and I've been prototyping direct drive extruders). I tried resetting the extrusion length at various points in the macro; but still get gaps even in the brim prime on first layers. That wouldn't be good if toolchanging with no prime tower...
