Messy, broken or stringy infill
The infill looks thin, broken, stringy or doesn't join up, even though the walls look fine.
Also described as strange infill, infill not printing, broken infill, infill gaps, stringy infill, patchy infill, infill problems
Try these in order
Most likely and quickest to check first. Change one thing at a time so you know what fixed it.
Infill printed too fast
Slicers often print infill much faster than walls, so it under-extrudes first.
- Lower the infill speed, or set a maximum volumetric speed so the slicer slows it automatically.
Partial clog or wet filament
- Check extrusion by pushing filament through by hand, and dry the spool.
Infill lines too thin
- Set infill line width to at least the nozzle diameter, and try 'infill every 2 layers' off.
Infill pattern catching the nozzle
- Use gyroid or cubic instead of grid, which crosses itself in the same layer.