3D printing troubleshooting
Clogged nozzle (not extruding)
Also known as: no plastic comes out, the extruder clicks or grinds the filament.
The symptom
No plastic comes out (or only a thin curly wisp), the extruder click-clicks skipping teeth or grinds the filament until it's chewed. Sometimes the print starts fine and dies a few layers in.
Causes and fixes, ranked by likelihood
- 1
Charred residue inside the nozzle (typical after switching materials or long very-hot printing).
Fix: Cold pull: heat up, push filament in (nylon or PLA), cool to ~90 °C and pull firmly — the plug comes out attached. Repeat 2-3 times. The cleaning needle helps with tip clogs.
Source: Prusa Knowledge Base — Print quality issues ↗ - 2
Heat creep: heat climbs the heatbreak, the filament softens too early and jams (prints dying mid-way).
Fix: Make sure the hotend fan (the small one, not the part fan) ALWAYS spins and is clean. Reduce long, frequent retractions, especially with PLA.
Source: Prusa Knowledge Base — Print quality issues ↗ - 3
Temperature too low for that filament: not a clog, just plastic that can't melt at the requested rate.
Fix: Check the SPOOL maker's range (not the material in general) and go to its upper half to rule this out.
Source: Simplify3D — Print Quality Guide: Clogged Extruder ↗ - 4
Brass nozzle eaten by abrasive filaments (CF, GF, glow): the bore deforms and jams.
Fix: Switch to a hardened steel nozzle for abrasives. A nozzle is a cents-level consumable; an afternoon of clogs is not.
Source: Simplify3D — Print Quality Guide: Clogged Extruder ↗
hotend tools that help here
Related
FAQ
- How often should a nozzle be replaced?
- Brass with normal filaments: hundreds of hours no problem; inspect it if lines widen or under-extrusion appears. With abrasives, brass dies within tens of hours — go hardened steel from the start.
- The extruder clicks but the nozzle is new — what do I check?
- The click only says 'I can't push': it may be the nozzle, but also low temp, heat creep, badly seated PTFE, or a first layer squished so hard (Z-offset) it seals the tip against the bed.
Sources & references
This page is cross-checked against public manufacturer documentation and reference technical guides:
- Manufacturer Prusa Knowledge Base — Print quality issues ↗
- Technical guide Simplify3D — Print Quality Guide: Clogged Extruder ↗
Still stuck? Back to the quick diagnosis or check which materials your printer can handle.