Extruder Clicking, Grinding & Under-Extrusion

A rhythmic clicking or squeaking sound from the extruder means the gear is skipping over the filament instead of pushing it — the single most common early-ownership problem.

Quick checklist

1. Idler tension — the spring-loaded idler door should be firm but not crushing; over-tightening it can bite too hard into soft filament and under-tightening lets the gear slip.
2. Partial nozzle clog — if the hotend needs more force to push filament than the extruder can provide, it'll grind the filament down to a smooth patch instead of feeding it. Try a cold pull (see hotend maintenance).
3. Wrong temperature — too cold for the material means the plastic isn't soft enough at the nozzle tip, causing back-pressure.
4. PTFE tube / heatbreak gap — a gap between the PTFE tube and the heatbreak lets filament ooze and re-solidify sideways, jamming the path.

Tip: If you see a smooth, shiny flat spot ground into the filament near the extruder gear, that confirms grinding — the fix is almost always temperature or a partial clog, not the extruder itself.

Under-extrusion symptoms in the print

• Visible gaps between adjacent lines that should be touching
• Weak layer adhesion / parts that snap along layer lines
• Thin, wispy top surfaces

Fixing it

1. Do a filament unload/load cycle from the LCD menu to confirm smooth feeding with the hotend hot.
2. Increase nozzle temperature in 5°C steps if using generic filament with unknown specs.
3. Check the idler door engages evenly — filament dust buildup on the gear can also reduce grip; clean it with a small brush.
4. If grinding persists at a fresh spot on the filament with correct temperature, suspect a clog and perform a cold pull before printing again.