Medium 15-35 min PLAPETGTPUABSASA

Under-Extrusion

Printed lines look thin or incomplete, with gaps in walls, sparse top surfaces, or weak layers.

Under-Extrusion example 1
Under-Extrusion example 2
Under-Extrusion example 3

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Likely causes

Partial nozzle clog
Perform a cold pull or nozzle cleaning. If the issue started after abrasive or old filament, inspect or replace the nozzle.
Filament path has too much resistance
Check spool drag, tangled filament, PTFE tube bends, and extruder tension. TPU is especially sensitive to resistance.
Printing too cold or too fast
Raise nozzle temperature by 5 C steps or lower speed so the hotend can melt enough plastic.

Recommended settings by material

MaterialNozzleBedFan
PLA 195-210 C50-60 C80-100%
PETG 230-245 C70-80 C30-60%
TPU 220-235 C40-50 C30-50%
ABS 240-260 C95-110 C0-30%
ASA 240-260 C95-110 C0-30%

Prevention tips

Change one setting at a time and reprint a small test piece.

Keep filament dry and store open spools in sealed bags or dry boxes.

Clean the build plate regularly and verify the correct slicer profile before long prints.

Related problems

StringingWarpingFirst Layer Not Sticking

Last reviewed Jun 15, 2026. Troubleshooting content is for reference only.