¶ FR2849：Retract issue, filament cannot be returned to CFS hub.
¶ Applicable models: K2 Plus
¶ Why does this prompt appear
When the printer performs filament unloading, the filament has been pulled out of the extruder, and the filament detector of the extruder has been released, but the filament detection at the hub outlet position of the CFS is still in a triggered state. Possible reasons include:
The filament spool did not rotate correctly during unloading, causing the filament to fail to retract into the CFS.
Excessive resistance or filament jam somewhere in the PTFE tube, affecting filament retraction.
Abnormal triggering of the filament detector corresponding to the hub outlet slot or malfunction of the hub outlet.
¶ How to solve
Spool problem: Check if the spool diameter is too small or deformed, causing the CFS drive wheel to fail to rotate the spool smoothly, or check if the spool is jammed.
Buffer jam:
Check hub outlet extrusion status: Check if there is a jam at the hub outlet. If jammed, follow the CFS hub outlet jam handling procedure Troubleshooting for CFS hub filament clogged.
Filament break detection abnormality at hub outlet: If the filament break detection metal dome at the hub outlet has not sprung up, it may be jammed by filament debris. In this case, disassemble the hub outlet and clean the debris.
¶ General troubleshooting steps
Check the spool: Ensure the spool is working normally, not jammed or deformed.
Check the buffer: Confirm if there are any faults or jams in the buffer.
Check hub outlet status: Ensure the hub outlet extrusion is working normally without blockage.
Check filament break detection: Confirm if the filament break detector at the hub outlet is working properly.