I tried printing with PETG yesterday, and I noticed that it intermittently stops moving during the print for a few seconds. It doesn’t throw an error or anything, just stops and then after a few seconds resumes as if nothing happened. But this creates huge blobs where it stops. It only happens when printing PETG, not PLA. Could this be caused by a filament setting in my slicer? I’m using prusa slicer. I inspected the gcode and there are no stops, pauses or color changes etc. in it. The behaviour happens both when printing from octoprint and directly from SD card.
Edit: these random intermittent stops are 10-20 seconds long, causing massive blobs from oozing filament.
Edit 2: so it seems to not actually be a PETG specific issue, but rather a model size/speed issue. I can get it running without stops if I just reduce print speed. When I crank speed to 100% I start getting these weird 10-20 second long stops.
So I’m overloading the controller with a lot of gcode commands in rapid succession? I’m running at slightly lower than manufacturer default Max.
SOLVED: the gcode resolution was set too fine, I increased it from 0.0125mm to 0.5mm as described here and the stuttering disappeared.
It’s an anycubic Kobra 2.
It’s not small blobs like here, it’s huge blobs because the printhead doesn’t move for 10-20 seconds, so filament from the chamber keeps oozing while it just sits there.
Thinking about this again, could it be you have something like “wait for layer time” on and a very high minimum layer time set for your petg profile?
I was overloading the controller with gcode commands due to high gcode resolution. I dug a little in to the terminal and could see that locked it up due to a checksum mismatch of commands when using octoprint. I’m guessing a reading speed/buffer issue is the cause when using the SD card.
I decreased resolution from the profile default 0.0125mm to 0.5mm and it went away. I’m going to see how fine I can set the resolution without introducing the stutter, but at 0.5mm it still looks good.
I was potentially trying to execute 24,000 gcode commands per second with that resolution when moving at max speed, now it’s down to a more manageable 600 commands per second.
If its stopping 10 to 20 seconds there’s definitely something in the gcode making the printer hang. I’d try slicing the file again with a different slicer to be sure.