Thin Wall Problem

[JoduWei]

Version

Current revision + 2.2.52.0_win64_20200623

Operating system type + version

Windows 10

Behavior

See Screenshots

a_drive_frame_lower.3mf.zip

[supermerill]

#150

[n8bot]

The slicer is avoiding the overlap of the two external perimeters from the hole and the outside of the part, where they become so close as to require this. As @supermerill mentions in the issue linked, you need to enable the option to allow overlap of perimeters.

On the topic of the overlap of perimeters, Slic3r default behaviour is indeed to overlap all paths slightly.

From Slic34 Manual —­ Flow Math:

Path spacing is thus:

spacing = extrusion_width - layer_height * (1 - PI/4)

Is this behaviour still present in SuperSlicer? I'm not actually familiar with coding enough to understand everything and determine this answer myself. Sorry if this is a stupid question.

[supermerill]

yes it's the same,
but since 2.2.52, you can change that for perimeters with the perimeter overlap (% of the right part of the formula).

[n8bot]

Oh, nice!

I guess this is what is meant by this note on the release page:

• perimeter overlap #4 perimeter overlaps : total control over perimeter width vs spacing. These settings may allow you to retain the same perimeter quality when you under-extrude but without under-extruding. Also may help to hide infill pattern passing through the perimeter. These needs some experimentation to see if they are useful.
  • external_perimeter_overlap to control half of the overlap between the external perimeter and the inner one: 0% is no overlap, 100% is full overlap (current & default value)
  • add perimeter_overlap, same between every perimeter (and the other half with the external one)
  • add perimeter_bonding, that shrink the external-internal spacing, without growing the infill polygons.

Would you be able to point me to the area in the source code that this is done? Just the general direction if it's complex. I'm just curious, I don't have any intention on modifying anything.

[supermerill]

perimetergenerator.cpp (in the begining) for the use of it.
flow.cpp for the multiplication.
you can also search for the commit that reference the issue 4

edit: you can modify if you want, it's open source!