Gaps between walls and infill
You can see a gap between the outside walls and the infill or top layers, or thin walls are missing in the slicer.
Also described as gap between perimeter, walls not touching, thin walls missing, infill not touching walls, gaps in top layer edge
Try these in order
Most likely and quickest to check first. Change one thing at a time so you know what fixed it.
Not enough infill overlap
- Raise infill/perimeter overlap to 15 to 25% in the slicer.
Slight under-extrusion
- Calibrate the flow rate, and slow down the infill.
Walls thinner than the nozzle
The slicer skips walls narrower than about one line width.
- Make thin features at least twice the nozzle width (0.8 mm for a 0.4 mm nozzle).
- Turn on 'detect thin walls' or use the Arachne wall generator.