Struggling with fine prints and filament burning
Hey! I'm looking for some ideas on how to resolve a reoccuring problem I have with "unattended" prints that has fine details. In this case I have a lithography on the top side, including the name of a grandkid. This lights up - but that has nothing to do with the question.
If you look at both the lithography and the name part, there are burned parts. I'm aware that the "bridge" is pretty bad but to make the light sine through I've tried to make this as thin as possible which makes the slicer complain that "this is going to look awful". Regardless, there are burnt filament (the black parts) and I see that often when there are fine details to print. If I'm at the printer when it happens I can remove the burnt part with a pair of pliers while things are printed, but after it cools down it will end up destroying the print.
This was done using fine print, using PETG. The total diameter of the lid (the circle) is 150mm. This is printed with the top side (what you see) facing down (there are ledges under it, that makes the underside not able to touch the plate). I've done quite a lot of prints where this happens too - other lithographs that are printed standing up (vertical) where there's a lot of small movement of the nozzle.
I would appreciate ideas of what to look at/tweak to avoid this from happening. Also, while I can guess to why it happens, if you have ideas to why an ordinarily ok print turns into this, please share!
PS. I'm aware that the bridge part of this print is awful. I'll either fill up the space with paint or find a better way to print this circle. It's not related to my question.
PPS: I don't see the embedded image on the preview - so I attached it too.