Under-Extrusion

Also known as: Underextrusion

beginner Print Quality

When not enough filament is extruded, causing gaps and weak prints.

Under-extrusion occurs when less filament than expected comes out of the nozzle, resulting in gaps, weak layers, and poor print quality.

Symptoms

  • Gaps between lines
  • Thin, weak walls
  • Missing layers or sections
  • Rough, porous surfaces
  • Layer separation

Common Causes

  1. Partial clog - Most common
  2. Temperature too low - Filament not flowing
  3. Print speed too fast - Can’t melt fast enough
  4. Incorrect e-steps - Calibration issue
  5. Worn extruder gear - Not gripping
  6. Filament grinding - Extruder chewed through
  7. Tangled spool - Resistance to feeding
  8. Wrong diameter setting - 1.75 vs 2.85mm

Fixes

  • Check for and clear clogs
  • Increase temperature
  • Slow down print speed
  • Calibrate e-steps
  • Check extruder tension
  • Verify filament diameter settings
  • Increase flow rate as temporary fix