Lumpy infill between perimeters
Why does Slic3r insist on putting blue lines between perimeter lines, and more importantly, why do they print as lines of lumps?
The lines shown in red print smooth, but the blue ones in the close-up shots print first when a new layer starts, and they produce a line of lumps rather than a smooth layer.
The line of lumps then gets run over by the nozzle when it prints the red lines, and the lumps accumulate and roast on the sock covering the hotend, until they are large (and brown) enough to drop onto the printed part.
Is there a way to prevent this?
Thanks for any help, Mik
Re: Lumpy infill between perimeters
The blue lines are a "gap fill", filling a gap between the perimeter lines.
At the 2nd picture you see that the inner perimeter lines are getting very close, so the extrusions overlap partially. This is not good and it may be avoided by enabling the "thin walls" feature. The "thin walls" will replace the overlapping perimeter lines with wider gap fills, but the "thin walls" feature causes some loss of accuracy on perimeter corners, and it allows the "gap fills" to create single line features attached to the outer perimeters, which are usually ugly.
https://github.com/alexrj/Slic3r/issues/3509
Usually the gap fills do not cause any harm, but you claim that the gap fill collects an already printed material over the E3D sock. What material is it? The only material that would do that excessively is PET-G.
Vojtech
Re: Lumpy infill between perimeters
The blue lines are a "gap fill", filling a gap between the perimeter lines.
At the 2nd picture you see that the inner perimeter lines are getting very close, so the extrusions overlap partially. This is not good and it may be avoided by enabling the "thin walls" feature. The "thin walls" will replace the overlapping perimeter lines with wider gap fills, but the "thin walls" feature causes some loss of accuracy on perimeter corners, and it allows the "gap fills" to create single line features attached to the outer perimeters, which are usually ugly.
https://github.com/alexrj/Slic3r/issues/3509
Usually the gap fills do not cause any harm, but you claim that the gap fill collects an already printed material over the E3D sock. What material is it? The only material that would do that excessively is PET-G.
Vojtech
Thank you very much for the explanations, much appreciated.
I have already started to experiment with the 4 different "Quality (slower slicing)" settings and noticed that the blue lines disappear with some combinations, and that larger gaps appear with others. I'll check it again more systematically with your explanations.
The filament I use most at the moment is Polymaker PC-plus and PC-Max.
Re: Lumpy infill between perimeters
I thought I posted this picture before, but it seems I only prepared it and did not post it.
It shows the line of lumps along the flat side of the ellipse, after the filler line has been deposited. During the next pass, printing the perimeters, some of the material accumulates on the nozzle and gets dropped elsewhere later.
The material is Polymaker PC-Plus clear.
Re: Lumpy infill between perimeters
I personally dont have experience with polycarbonate material, but from your description it seems it behaves similarly to PET. I had a lengthy discussion yesterday with our print expert Jindra. We did not find a cure yet. Simply lifting the nozzle by the live adjust function will reduce the effect of material collecting on the nozzle, with the negative effect of reducing adhesion to the bed.
Re: Lumpy infill between perimeters
Cheers, thanks for trying !
Mik