Struggling with pillowing or some more severe version of it
(this is copied from my stack exchange post about the same problem, just trying to spread this as much as possible)
Info about the prints:
Using PrusaSlicer with 0.1 mm layer heightUsing PETG, 1.75 mm240 °C nozzle, 90 °C bed0.4 mm hardened steel nozzlePrinting at 40 mm/s9 top layers, 7 bottom layersUsing 15 % infill (slightly more than recommended, trying to keep this low for weight)
Here's a timelapse of the full print (I don't have footage of each individual layer being added, but this somewhat shows what's happening)
I've done some research, and I think the general term for this anomaly is called "pillowing", but I think what I've encountered seems to be a much more significant and harmful version. Essentially, it seems to nail the infill parts relatively well, not messing up any of the thin walls, but right as it tries to bridge over them, it seems to fail, creating these odd chunks of chaotic shards. This eventually gets refined as more top layers are added, but I don't want to simply add more top layers, as it seems that 0.9 mm should be enough for most applications. This would probably be a lot more inefficient w/ more top layers, so I'm just trying to figure out the root of the issue.
I've also seen some resources saying that the temperature used is too high and that the temperature is too low, but those seem to have different-looking problems. I'm not sure as well whether the hardened steel nozzle demands a higher temperature as this is one of my first couple prints w/ it. Other than this pillowing problem, the walls seem to be smooth and well-defined, so I'm not sure whether I should change temps.
thanks in advance for y'all's help, I've been trying to push this project forward for a while, so any quick help is greatly appreciated!
RE: Struggling with pillowing or some more severe version of it
If you're not wanting to up your top layers, try increasing your infill. I know you said you want to try and keep weight down, so try Adaptive Cubic with a higher % of infill. This will keep the infill sparser in places that don't need infill but get denser as it approaches top surfaces. You can compare your part weight in Prusa Slicer's summary to see how your weight compares.
RE: Struggling with pillowing or some more severe version of it
hmm, I see, so you're saying the amount that I have definitely isn't enough? I can try like about 30%, I just sorta figured it should be able to work with low infill. was hoping to see if there were some temperature or other things I could fix to allow me to work with low infill
RE: Struggling with pillowing or some more severe version of it
Pillowing is usually caused by too sparse infill, yes. What you can try doing is use a low infill % then set a height modifier near the top of the part to increase the infill %. Then again, that's why I use Adaptive Cubic. I don't want to mess with that kind of thing on my prints.