in general I have the issue that if the print head travels with no extrusion, it leaks material a bit and quickly loses pressure. When it goes back to printing, it takes a few (2 to 5) cm until the pressure is back and a satisfying amount of plastic is extruded. I use Cura, and have at the moment retraction disabled (it made more problems than it solved with my old printer), so I guess I’ll be able to figure out good settings with a bit of trial and error here.
What I am not sure: would these settings affect resume after filament runout? I suppose not… I had my first (unplanned) filament runout, and the resume feature worked nice! Happy with that! However, again I had the pressure issue: For ~5 cm the extrusion was too low to catch, and only then it continued to print decently. Here’s a photo, where you can very well see the gap:
Disclaimer: I don’t have my Snapmaker yet. I’m cutting my teeth on an Ender 3 right now.
I think you may want to enable retraction and play with the distance, retract speed, and prime speed. Someone on this forum may have already posted what they’ve found to be the “ideal” settings for that are. For the Ender 3 it’s supposedly 5-6 mm retraction and 25mm/s speed from what I’ve found. Because the SnapMaker 2 is direct drive and not using a bowden tube, it’s my understanding that the retraction distance should be much less, but I don’t know what the actual distance and speed should be set to.
Note: The “prime” speed is how fast it shoves the filament back down into the nozzle before it starts printing again. You would want to increase this if you were still getting gaps after enabling retraction.
Thanks @gilahacker. I am petty sure that I can get a grip on underextrusion issues in normal print, that’s what I meant in the first part of my post. However, my question is: Can I influence filament priming after filament runout? That’s nothing I can influence via slicer right? I suppose that filament runout resume procedure is kidn of hard coded into the firmware, but I may be wrong here. Is there some G-Code to influence this?
When you feed new filament in after a filament runout, the machine will extrude some plastic to prime the nozzle. I remove this with tweezers before it gets to the part and have not had issues of under extrusion when it resumes printing.
If youre nozzle is oozing significantly in the time it takes to resume printing then perhaps you are printing at higher a temperature than you need. In general oozing is helped by lower temps, coasting and retractions.
Disclaimer: I have only used the filament runout feature once on FW 1.10
