Why thin walls disappear in the slicer
A CAD model can contain details that are too small to reproduce with the selected nozzle and extrusion width. The slicer must either adapt the toolpath or remove the feature entirely. This is especially important for thin ribs, small text, narrow walls and fine decorative details.
Nozzle diameter and extrusion width are not identical
A 0.4 mm nozzle does not necessarily produce exactly 0.4 mm wide extrusion lines. The actual width depends on the slicer profile.
Features smaller than a printable extrusion path
A feature may exist in CAD but disappear in Preview because the slicer cannot generate a useful toolpath.
Arachne
Variable-width perimeter generators such as Arachne can preserve some thin features better by adjusting extrusion width. But there is still a minimum feature size.
Slicer Preview is essential
Before export, inspect: If the feature is missing in Preview, it will not magically appear in the print.
- layer view
- perimeters
- thin walls
- text
- holes
Redesign if needed
Possible options:
- make the wall thicker
- enlarge text
- widen ribs
- use another nozzle
- change orientation
Generator relevance
For generators with text or thin geometry, it's worth checking the minimum dimensions before printing rather than relying solely on the default value.