I like many others have a problem when printing PETG-CF. The nozzle seems to collect filament and then after enough accumulates it deposits it on the print. This can result in many different issues depending on where it drops it.
I have my filament tuned very well and my prints look great, until the blob comes off. If the prints are small, less than an hour or two it does not accumulate enough to be a problem but long prints always suffer. If I do a manual pause and wipe the nozzle with a brass brush then resume, all is well. But I do not want to babysit long prints.
The stock nozzle wiper is ineffective for this problem as it just moves the blob to the front and back of the nozzle and then it will deposit 2 blobs somewhere. I have printed the “Brass Brush” nozzle wiper to replace the stock unit and it works very well at removing the build up from all sides of the nozzle.
But I am still using the “Manual” Pause and resume.
Can someone help me with some custom G-Code that I can insert every so many layers that will Pause , wipe and resume after the wipe ?
I have not experienced the layer shift issue after pausing or a filament change but maybe an X-Y home would also be a good idea to have in the code.
This sounds feasible using the “Template Custom G-code” insert. This can then be used by right clicking the appropriate layer and selecting “Add Custom Template”. The wipe g-code can be found in the “Machine start G-code” section. Something like code below. I added the filament retract which might not be needed. Please use this at your own risk as I have not had a chance to verify it.
G1 X60 Y265 F15000 ; nozzle wipe position
G92 E0 ; zero extruder
G1 E-0.5 F300 ; retract filament
G1 X100 F5000 ; wipe right
G1 X70 F15000 ; wipe left
G1 X100 F5000 ; wipe right
G1 X70 F15000 ; wipe left
G1 X100 F5000 ; wipe right
G1 X70 F15000 ; wipe left
G1 X100 F5000 ; wipe right
G1 X70 F15000 ; wipe left
G1 X60 F5000 ; clearance
As you figured out you don’t need the pause. The slicer inserts the gcode at the beginning of the layer and once complete it will continue on with the start of the layer.
Homing X and Y “shouldn’t be needed” and might add a zit to the outside of the part as the nozzle returns to the part because of oozing. That was the only issue I found when I did some testing of homing XY during a print.
It will be interesting to see which works best for you situation, homing vs not homing.
The only thing I am concerned about is maybe The code should start with dropping the Z a bit before going to the poop shoot. If the layer ends in the front of the part it may leave a scar.