RE: Why extra bits of filament are extruded when printing the first few layers?
one more idea. When you make changes in a PrusaSlicer input field. You have to move out of that field and click somewhere else, or it won't actually save the edits you just made.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Why extra bits of filament are extruded when printing the first few layers?
I don't know whether we are discussing exactly the same thing. Under Print Settings on the right, it says that I am under Quality. There is a Speed and a Draft choice however no Stealth. Under Printer Settings, Dependencies, it says "default print profile: 0.15mm Quality @MK3".
RE: Why extra bits of filament are extruded when printing the first few layers?
I solved that problem with that code in Filament Settings -> Custom G Code, reducing a lot initial oozing:
M104 S175 ; set initial extruder temp to a lower level avoiding oozing M140 S[first_layer_bed_temperature] ; set bed temp M190 S[first_layer_bed_temperature] ; wait for bed temp G28 W ; home all without mesh bed level G80 ; mesh bed leveling M104 S[first_layer_temperature] ; set final extruder temp after bed leveling M109 S[first_layer_temperature] ; wait for extruder temp
Change is simple.
-Move the original head heating commands M104 and M109 after mesh bed leveling.
-Insert before bed setting temperature command a M104 setting the head to a non oozing value. (I found that 175C is perfect for PETG, oozing was minimal).
Delay is ~35 seconds, very little time compared to a typical print time. And since the head is heated in oozing temperatures in the final position above the "intro line", any "tail" will be "consumed" in that line.
If you want to minimize as possible that 35 seconds, move 2nd M104 command (that sets the final head temperature) just before G28 (and after M90). The head will start increasing the temperature to the final setting just after the bed has reached its final temperature.
RE: Why extra bits of filament are extruded when printing the first few layers?
I changed a little the code, in order to rise the nozzle some mm above bed while waiting for the final step of head heating.
M104 S175 ; set initial extruder temp to a lower level avoiding oozing M140 S[first_layer_bed_temperature] ; set bed temp M190 S[first_layer_bed_temperature] ; wait for bed temp G28 W ; home all without mesh bed level G80 ; mesh bed leveling G1 Z5.0 F720 ; stay 5 mm above bed G1 X0 Y-3 F1000 ; go outside print area M104 S[first_layer_temperature] ; set final extruder temp after bed leveling M109 S[first_layer_temperature] ; wait for extruder temp G1 Z0.2 F720 G1 Y-3 F1000 ; go outside print area
I have done a lot of prints since that change, and the problem vanished completely. The only action needed is to remove the "tail" that is hanging from the nose, before starting a print. Then oozing is minimal, and it is always absorbed by the "cleaning" line outside the print area.