I print a lot of objects that need ironing, but it’s very hard to fine tune the settings because heat creep increases the more objects I add to the plate. Using print by object has helped a little, but there are still noticeable issues.
I had a thought to add a pause to cooldown the nozzle to a certain temperature in between each object. I thought I could do this manually by adding pauses or custom g-code at the specific layer change, but that is disabled in print by object mode. I did notice that there is a section in printer settings labeled “Printing by object G-code”, but after lots of googling and searching the forum I was unable to figure out what that does. Does it insert the gcode in between each object? That’s what I’m looking for. If nobody knows I suppose I could just test it out too.
If you’re aware of that, or another way to fix ironing during long prints, please let me know. Thanks!
For anyone encountering this in the future, I figured this out! The gcode in this box does in fact run in between each object. I tried a bunch of different ways to solve my ironing/heat creep problem, but the simplest solution is just to put a pause in between each object. The nozzle automatically cools to 90C when paused, which is enough to deter heat creep for the next object, at least in my case.
You could set an automatic 5 minute pause if you want to let it run with no user intervention. I chose to do a pause that waits for user input to restart, mainly because I wanted to print another purge line after each pause. I found that it was hard to get a clean start to the next model after the pause, even with a wipe before starting. The purge line solves that. I’ll include the code below. While paused you should remove the previous purge line. You should also make sure to set the Z-height high enough to clear your other objects before and after moving to the purge line area. I’ve marked those spots with comments in the gcode.
;====COOLDOWN=====
M400 U1 ; pause for user
;=====PURGE LINE=====
G1 Z5 ; Move Z-axis to 5mm FOR CLEARANCE OF OTHER OBJECTS
G1 X20.0 Y1.0 F18000 ; Move to start position at X18.0 Y1.0 Z0.8 with a speed of 18000 mm/min
G1 Z0.2 ; Move Z-axis to 0.2mm
G0 E2 F300 ; Extrude 2mm of filament at a speed of 300 mm/min
G0 X240 E15 F{outer_wall_volumetric_speed/(0.30.5) * 60} ; Move to X240 while extruding 15mm of filament, speed calculated based on settings
G0 Y11 E0.700 F{outer_wall_volumetric_speed/(0.30.5)/4 * 60} ; Move to Y11 while extruding 0.700mm of filament, at a quarter of the calculated speed
G0 X239.5 ; Move slightly on the X-axis to X239.5 without extruding
G0 E0.2 ; Extrude 0.2mm of filament
G0 Y1.5 E0.700 ; Move to Y1.5 while extruding 0.700mm of filament
G0 X20 E15 F{outer_wall_volumetric_speed/(0.3*0.5) * 60} ; Move back to X18 while extruding 15mm of filament, speed based on settings
G1 E-1 F1800 ; retract filament
G1 Z5 ; Move Z-axis to 5mm FOR CLEARANCE OF OTHER OBJECTS
