Massive stringing and blobs with PETG, all well with PLA
Hello,
I've done several prints with PLA so far and most of it went really well. For one project I wanted to use PETG because of its higher temperature stability. But my first efforts here turned out quite terrible.
The STL model is attached. Its geometry is made so that it fits in an existing aluminium profile. The holes have different diameters to find the best one for the screws to put in. The black one above is PLA (printed with an older version of PrusaSlicer), the others are PETG.
A closeup of the PLA print:
The three PETG prints were made with these settings (top to bottom):
1. 0.10 mm layer height, 245 °C, new Arachne perimeter feature (made big errors, I'm not going to use this anymore)
2. 0.10 mm layer height, 245 °C, classic perimeter, otherwise default settings
3. 0.10 mm layer height, 240 °C, classic perimeter, otherwise default settings
There are no visible differences between the last two. I could reduce the stringing with PLA by reducing the nozzle temperature by 5 °C but this time it didn't help.
All filaments are Prusament. The white PETG is brand new, I only opened the sealed bag yesterday (ordered and delivered a few months ago). The printer is a Mini+.
What's the problem here? Can PETG even produce accurate quality like PLA or is it more for the rough things?
RE: Massive stringing and blobs with PETG, all well with PLA
PETG can be tough to print - it takes perfect Z offset and settings. It can also be stringy.
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Chuck H
3D Printer Review Blog
RE: Massive stringing and blobs with PETG, all well with PLA
I've also read some other sources. What helped so far was reducing the temperature from 250 to 235 °C (below the range suggested for the material) and increasing the retraction length from 3.2 to 6 mm (more leads to missed spots in the print). The higher temperature does not result in more strength of the prints. PETG is always noticeably more flexible than PLA. I don't know how these presets in PrusaSlicer were made, but they're really not a ready-to-use solution. Everybody needs to fiddle around and tweak it into something working. And these changes still result in an inferior print quality than with PLA.
RE: Massive stringing and blobs with PETG, all well with PLA
Count me in on the lowered temps being an option. Have you tried a different roll of PETG and/or drying what you have? Also for whatever reason, white is a PIA for me. Both PLA and PETG.
Mini+MK3S+XL 5 Tool
RE: Massive stringing and blobs with PETG, all well with PLA
I only have this single spool of PETG (and the other black PLA), nothing more yet, and they will still last quite a while. I also haven't looked into the drying thing yet, trying not to need it. I can regenerate silica gel bags and my PLA spool now sleeps at impressive 10% rel. humidity (according to the digital sensor I put in the bag). The room (with the opened PETG spool) is currently around 45%.
It also seems to depend on the print forms. One of the models I've printed a few times now usually is pretty good, and other smaller parts seem to depend on how I arrange them on the print bed. I have the impression that the printer movements have an effect on the amount of stringing. Maybe the parts need to be placed further apart to reduce the strings between them.