Artififacts when slicing a thin-walled sphere
I'm trying to print a half-sphere with fairly thin walls, 0.9mm. However, when the walls transition from a horizontal to a more vertical angle, or the opposite, Prusaslicer inserts a lot of artifacts into the g-code that create a very non-uniform result, is very inefficient and can cause a lot of stringing. I'm hoping to get it to print these layers in a single smooth motion.
At horizontal angles it uses internal perimiters to pad the width of the wall to the desired thickness, at medium vertical angles it uses a gap fill, and when completely vertical it doesn't use anything (the external perimiters are wide enough). In the transitions between these angles the layer is dotted with hundreds of small dabs of either padding type. It's especially bad when it mixes internal perimiters and gap fills.
I'm using a model I created myself and I've tried modifying it in various ways without much success. Unfortunately I can't make the walls thick enough to remove the problem.
An example of a perimiter-gap fill boundary layer:
An example of a gap fill-nothing boundary layer:
Displaying the retractions (blue and red dots) in a perimiter-gap fill layer:
Example of artifacting visible on print:
The project: Trash_lid_repaired
Best Answer by Berengal:
After some more sleuthing I installed SuperSlicer (a fork of PrusaSlicer) to see if it would be able to handle the model better. It did so right away without any fiddling with extrusion width. It emitted a single gap fill line of uniform width on each layer and there's no sign of any artifacting. It also decreased the projected print time by 30%.
RE: Artififacts when slicing a thin-walled sphere
You can play with the extrusion widths and choose something other that 0.45 for perimeters; use Detect Thin Walls; or possible use a different slicer, I've heard Cura does better at maintaining desired wall thickness than Prusa Slicer. Do a forum search, there have been many rather long discussions of this exact issue.
RE: Artififacts when slicing a thin-walled sphere
I found some other topics similar to this. Unfortunately no real solution. Changing the extrusion width moves the problem around, but because the shape is spherical it always shows up somewhere. It didn't go away until I changed the extrusion width to something completely absurd like 0.05mm. Cura doesn't run at all on my pc, but I found some reference in other forums that showed it working better on similar objects.
RE: Artififacts when slicing a thin-walled sphere
After some more sleuthing I installed SuperSlicer (a fork of PrusaSlicer) to see if it would be able to handle the model better. It did so right away without any fiddling with extrusion width. It emitted a single gap fill line of uniform width on each layer and there's no sign of any artifacting. It also decreased the projected print time by 30%.