Strange, dark horizontal stripes in a "moon lamp" when lit through
I once thought that after a year of intensive use of my MK3S+ I can handle all rare cases when something is not going good, but I got suck with this one.
I'm trying to get a print of moon lamp. I initially started with this https://www.prusaprinters.org/prints/23859-designer-lithophane-moon-lamp and I did a print following the instructions, whereas IIRC I forgot to increase the number of perimeters from the standard 2 to 4-5 as in the instructions. I used "Das Filament" PLA "weiss matt", "0.2 Quality" preset and 100% infill. Certainly, used the Prusa Slicer, last version of it. The result was that, even though the printing went 100% well and the print looked almost perfect when looking on it in normal lightning, if I put a lamp bulb (well, LED lamp) inside, the result shows large number of dark layers or a kind of stripes going all the way along on many places. See the attachments.
At this time I thought the moon model is not good, and bought a commercial model which was said to be tuned multiple times. This time I printed with the same filament, with the "0.1 details" preset with 100% infill, not other changes in setting. The result was still almost exactly the same. That much the same that I even did not attach the pictures from the first attempt here. I "paid" with 62 hours of printing for this and thought for the next time, it is better to ask around first 😉
I believe it is something in settings, and it is not about filament or about the level of details. Some while ago, I also observed strange shifts when a text is embossed on a side of a relatively thin wall, see the attachments. Some traces at the same height as the text show up on all other walls around the model. I cannot say for sure, but this looks for me as another effect of the same problem or missing right settings. BTW, some very long time before, I did actually have a real and classical "layer shift" problem, and fixed it by tightening the bolts on one of the pulleys.
I'm sure, that print can work better and as expected, since there are many pictures of other prints of such a moon lamp w/o any dark stripes.
Should I set 20 perimeters so that the walls will be made of almost perimeters only? Or use only 90% infill with concentric pattern as some folks describe their settings in other forums?
Any ideas, suggestions?
Thanks!
