¶ Issue Description
When printing with the External Spool, the system continuously monitors the extrusion motor’s force to detect abnormalities. If an abnormal extrusion force is detected, the print job will automatically pause until the issue is resolved.
This warning is designed to detect “Air Printing” (extruder running without material output).
Possible causes：
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Filament is too thin or worn, causing the extruder gear to slip
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A clog in the hotend prevents filament from being extruded through the nozzle
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The filament type set in the slicer does not match the actual material in use
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The filament triggered the toolhead filament sensor, but the extruder gear did not properly engage with it.
Notes on detection conditions:
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Detection is only available when using the external spool with the following filaments: PLA, PETG, PLA-CF, PETG-CF, PA-CF, and PET-CF.
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Extrusion flow rate must exceed 9.6 mm³/s.
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Detection is Only supported with a 0.4 mm hotend.
Detection accuracy may vary depending on filament type and print speed. Delays in detection are possible. After clearing the fault, carefully inspect the printed part before deciding whether to continue printing.
¶ Troubleshooting
Safety Notice: Before disassembling the toolhead, always power off the printer to avoid electric shock.
¶ Tools, Equipment, and Materials
- H2.0 hex screwdriver
- H1.5 hex screwdriver
- Flush cutter / scissors
- Flush cutter / scissors
¶ Troubleshooting Workflow
See the detailed steps below:
¶ Troubleshooting Steps
Users may adjust the order of steps depending on their situation.
¶ Step 1. Check Filament Settings in the Slicer
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If the filament type set in the slicer does not match the actual filament being used, air printing may occur. Adjust the slicer parameters or replace the filament to ensure they match.
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Try extruding again. If the air extrusion warning persists, proceed to Step 2.
¶ Step 2. Cool Down the Hotend and Cut the Filament
- Set the hotend temperature to 0 °C and wait until it cools down to room temperature.
- Press the cutter lever to cut the filament.
¶ Step 3. Heat the Hotend and Attempt to Pull Out the Filament
- Set the hotend temperature to the printing temperature of the filament and wait until it heats up.
- Remove the PTFE tube on top of the extruder.
- Rotate the extruder motor in reverse while gently pulling the filament upward.
¶ Step 4. If Filament Cannot Be Pulled Out → Clean the Extruder
The extruder may be clogged. Please refer to How to Check Which Part is Clogged in H2S for cleaning instructions.
After cleaning, try extruding again. If the blockage persists, proceed to Step 5 to troubleshoot the hotend.
¶ Step 5. If Filament Can Be Pulled Out → Check for Hotend Blockage
If the filament was successfully pulled out in Step 3, the extruder is likely not clogged. The hotend may still be clogged.
Please refer to Nozzle/Hotend Unclogging Procedure for H2S
- If extrusion works normally after cleaning, the problem is resolved.
- If extrusion still fails, the hotend may be worn out or permanently damaged. In this case, replace the hotend.
If the above steps do not resolve your issue, please submit a ticket and upload your printer logs
¶ Conclusion
We hope this guide will provide you with useful information and help you solve problems.
To ensure that you operate safely and effectively, if you have any doubts or questions about any steps in the guide, please contact our Customer Support team before starting the operation.
We are always happy to answer your questions and provide support.
Click here to contact online technical support (service hours 9:00-21:00)
¶ Equivalent Codes
The following HMS codes represent the same type of issue.
| HMS Code | Description |
|---|---|
| 0300-0900-0002-0003 | The extruder is extruding abnormally. It may be clogged, or the filament may be too thin, causing the extruder to slip. |