A clicking or ticking extruder is the sound of the stepper motor skipping steps. The motor tries to push filament through, meets resistance it cannot overcome, and snaps back. Per Prusa’s extruder-noises guide, that skip under load is the root of most clicking, and it points back to a short list of causes almost every time.
The click tends to show up on the first layer or partway through a long print, and it often travels with under-extrusion. You see thin walls, gaps in the top surface, or filament that stops feeding. Work the causes in order and reprint the same test after each fix.
The material in the spool changes the odds. PLA feeds easy and rarely clicks when it is dry. PETG and nylon run hotter and pull in moisture faster, so a damp spool thickens the melt and stalls the extruder. TPU is flexible and clicks when you push it past its speed range.
Likely causes, ranked
| Likely cause | Fix | Severity |
|---|---|---|
| Nozzle too cold or partly clogged | Raise the nozzle 5 to 10 C, or clear a clog with a cold pull. A cold or blocked nozzle is the most common stall. | hi |
| Extruder idler tension off | Too loose and the gear slips on the filament; too tight and it grinds. Set a light, even grip. | hi |
| Bowden tube or PTFE restriction | Reseat the tube fully into the fitting and look for a melted or kinked end that chokes the path. | md |
| Extruder gear loose or worn | Tighten the grub screw on the gear and check the teeth. Worn teeth cannot grip the filament. | md |
| Print speed too high | Drop speed 10 to 20 mm/s, especially on the first layer and the outer walls. | md |
| Wet filament | Dry the spool, then reprint. PETG and nylon click more once they take on water. | lo |
Quick fixes to try first
Print a simple test cube or a calibration line, then work top to bottom and reprint after each step.
Heat and clear the nozzle
Raise the nozzle 5 to 10 C and push filament through by hand. If flow returns, a cold or partly clogged nozzle was the stall.
Set the idler tension
Find the tension screw on the extruder and turn it until the gear grips the filament with light, even pressure, neither slipping nor grinding.
Reseat the Bowden tube
Loosen the coupling, push the tube fully to the bottom of the hot end, and retighten. A gap there chokes the melt path.
Slow the print down
Drop print speed 10 to 20 mm/s and reprint. A stock extruder stalls less when you ask it for less flow.
Dry the filament
If the click came with popping or a rough surface, dry the spool and reprint. Wet PETG and nylon thicken the melt and stall the gear.
Deeper tuning to try next
When clearing the nozzle and tensioning the idler do not end the click, the hardware and the calibration are the next place to look.
Inspect and clean the extruder gear
Pull the filament out, brush the gear teeth clean, and tighten the grub screw. Teeth packed with dust or worn flat cannot grip.
Check the hot end for a clog or heat creep
Run a cold pull to clear residue, and confirm the hot-end fan runs so filament does not soften high in the heat break.
Recalibrate e-steps
If the printer under-extrudes with no click, mark 100 mm of filament, command a 100 mm feed, and trim the e-steps until it matches.
How the material changes things
The material sets how willing the filament is to flow. PLA feeds easy at 200 to 210 C and rarely clicks when it is dry. PETG and nylon run hotter and soak up moisture fast, so a damp spool thickens the melt and stalls the extruder. TPU is flexible and clicks when you push it past its speed range, so slow down for flexibles.
Mistakes that bring it back
A few common habits hide the real cause or bring the click back once it is gone.
Avoiddo not
- Cranking the nozzle far above the filament range. It hides the click but burns the filament and, on a PTFE-lined hot end, damages the tube.
- Over-tightening the idler until the gear grinds a groove into the filament.
- Ignoring wet filament on PETG or nylon. The click returns until the spool is dry.
- Changing tension, temperature, and speed in one pass, so the real cause stays hidden.
Key takeaways
- A click is the stepper skipping under load. The extruder cannot push filament through.
- Work top to bottom: nozzle or clog, idler tension, Bowden tube, extruder gear, then speed.
- Dry PETG and nylon first. Wet filament thickens the melt and stalls the gear.
- Change one thing at a time and reprint the same test.
For related problems, the under-extrusion guide covers thin walls and gaps, and the filament storage guide covers keeping spools dry.
Related guides
Related
Cross-reference
Sources & methodology
3 citations · reviewed 2026-07-10- 01Prusa Knowledge Base: Extruder noises (clicking and stepper skipping)accessed 2026-07-09Tier 1
- 02All3DP: Slipping or Clicking Extruder (troubleshooting)accessed 2026-07-09Tier 2
- 03Bambu Lab Wiki: Under-extrusion (overall and local causes)accessed 2026-07-09Tier 1