Concentric regions treated as perimeters in solid-layer infill
The infill for the solid top and bottom layers of this shape are being drawn, in part, with a concentric fill pattern. What's more, in this Speed view, the innermost segment is being drawn at 150 mm/s, which is my speed setting for perimeters. (The Feature Type view shows the infill as solid infill, not perimeters.) This fill scheme is visible on every layer except the first and last, but it rotates by 90 degrees on alternate layers.
Is this normal and expected? I don't remember seeing this kind of thing on solid layers before. It's not creating an overt problem for me, but the variation in speed and line thickness does seem to introduce some nonuniformity.
As far as I'm aware, there's no UI setting that corresponds to an infill pattern for solid top and bottom layers. Changing the infill patterns for sparse fill and for the top and bottom layers does not seem to make any difference.
This is on PrusaSlicer 2.7.2, Mac version. The .3mf file is attached.
Best Answer by Neophyl:
Its 'normal' - now. They changed solid infill a couple of versions back.
Topfill, bottom fill and normal sparse infill were all selectable for patterns basically forever. But the top and bottom patterns selected always only ever applied to the very outmost layer on the top or bottom. The rest were always with solid infill pattern with a 90 degree crosshatch pattern on alternate layers.
However they had complaints about the zigzag patterns on thinner areas of solid infill shaking printers around so they changed t to do those areas in a similar way to extra perimeters. Which is why you see a mixture of the 2 methods on your layers. The larger areas are still using the crosshatch.
There is no setting to restore the old behaviour though. You can't do anything about it except use an older version. As you can imagine this has produced several bug reports on the PS github. Most of them closed now as this is being done by design. There are still some open though. For example https://github.com/prusa3d/PrusaSlicer/issues/10573 or https://github.com/prusa3d/PrusaSlicer/issues/10677 etc
Ps to attach files here (or the PS github) you must zip them up. The allowed file types is very limited here. Its also best to check your post immediately after posting as the edit window is so short and you dont get any indication or warning if something wasnt attached.
RE: Concentric regions treated as perimeters in solid-layer infill
Hmm, I couldn't get the file to attach to the message. But you can download it here.
RE: Concentric regions treated as perimeters in solid-layer infill
Its 'normal' - now. They changed solid infill a couple of versions back.
Topfill, bottom fill and normal sparse infill were all selectable for patterns basically forever. But the top and bottom patterns selected always only ever applied to the very outmost layer on the top or bottom. The rest were always with solid infill pattern with a 90 degree crosshatch pattern on alternate layers.
However they had complaints about the zigzag patterns on thinner areas of solid infill shaking printers around so they changed t to do those areas in a similar way to extra perimeters. Which is why you see a mixture of the 2 methods on your layers. The larger areas are still using the crosshatch.
There is no setting to restore the old behaviour though. You can't do anything about it except use an older version. As you can imagine this has produced several bug reports on the PS github. Most of them closed now as this is being done by design. There are still some open though. For example https://github.com/prusa3d/PrusaSlicer/issues/10573 or https://github.com/prusa3d/PrusaSlicer/issues/10677 etc
Ps to attach files here (or the PS github) you must zip them up. The allowed file types is very limited here. Its also best to check your post immediately after posting as the edit window is so short and you dont get any indication or warning if something wasnt attached.
RE: Concentric regions treated as perimeters in solid-layer infill
Its 'normal' - now. They changed solid infill a couple of versions back.
Many thanks for the explanation.
As mentioned above, I had originally thought it was drawing the innermost loop at perimeter speed. But after some further experimentation, the slowdown seems to be caused by hitting the limit on max volumetric speed, probably because of the slightly thicker extrusion at the center. So, all good! 👍