Grinding Filament
Fix a grinding or clicking extruder — clear the downstream clog and check the extruder lever tension.
Grinding occurs when the drive gears remove material from the filament instead of advancing it. Look for plastic dust around the gears and a worn or flattened section of filament. Clicking alone does not confirm grinding: a motor can skip against resistance without visibly shaving the filament.
Choose the First Check
| Observation | Check |
|---|---|
| Spool stops turning or filament becomes taut | Spool and upstream path |
| Gears turn over a worn section | Damaged filament and gear cleanliness |
| Fresh filament also fails to feed | Lever setting, temperature, and hotend restriction |
| Feeding fails only on fast sections | Speed and volumetric demand |
| Motor does not turn during a valid extrusion command | Web Interface messages and support |
Stop the failed print before repeated attempts wear a deeper groove. Record the head, material, temperature, and point in the job where feeding failed.
1. Check the Spool and Filament Path
Check that material remains and the spool turns freely. Look for crossed turns, trapped filament, a deformed spool, or a kinked tube. Follow the path to the affected head: a loaded sensor does not prove filament reaches the gears.
Correct visible restrictions before reloading. For a break inside the tube, follow Filament Breaks Inside Tube. If resistance remains, use the detailed path inspection in Under-Extrusion.
2. Remove the Damaged Section and Check Grip
Unload using the printer's procedure for the material. Inspect the section inside the gears and remove the damaged portion before loading fresh filament. The gears may not recover their grip on a deeply worn spot.
Remove loose debris from accessible gear teeth with the mechanism stopped, following Extruder Disassembly if access is required. Do not brush moving gears.
Set the lever using Extruder Lever, which provides material-specific positions for the V4. Too little grip allows slipping; too much can deform filament. Increasing tension is not a remedy for a blocked nozzle.
3. Test Extrusion at the Correct Temperature
- Select the affected head. Use the standard loading/extrusion macro for the material, or set the temperature from its printer-specific filament profile.
- Wait for actual temperature to reach the target.
- Command a small extrusion through the Web Interface and observe feeding and material leaving the nozzle.
- If extrusion is continuous, proceed to a short print.
- If fresh filament begins grinding again, stop and inspect the hotend path.
A blocked nozzle or heatbreak, insufficient melting, or heat creep can resist feeding. Check the heatsink fan and material-appropriate chamber conditions before simply raising temperature. Follow Hotend Filament Jamming and Under-Extrusion.
After replacing the nozzle or heatbreak and finishing reassembly, run Auto Calibration, including its preparation steps.
4. If It Happens Only During Printing
Compare the failed section with the slicer preview. If it coincides with faster extrusion, restore stock speed and maximum volumetric flow settings and retest. See Volumetric Flow Rate.
If failure follows frequent retractions, compare edited macros and slicer settings with stock values. Change one setting at a time. Calibrate a new material profile after reliable feeding is restored.
For ordinary travel moves, restore the matching Vision Miner slicer profile's retraction values. For V4 tool changes, use Web Interface > Macros > System > Settings > Printing > Tool Change Retraction: choose the affected tool, then enter 5 mm for Retraction or 10 mm for Extrusion to restore that setting's firmware default. See Tool Change Retraction; confirm the available settings separately on V2/V3.
Verify the Result
Reload undamaged filament and repeat a short job containing the failing feature. Confirm steady feeding and no new dust or worn section.
Record the Diagnostic Results
If the motor does not turn, or grinding returns with a clear path and correct profile, stop repeated feeding attempts and contact support. Keep photos of the filament and gears, the affected head, Web Interface errors, and the conditions that reproduce the failure with your test notes.
FAQ
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