¶ Procedure
When the nozzle clog is more severe, you can use the cold pull method.
Before performing a cold pull, ensure that filament is loaded in the toolhead you intend to clean.
¶ 1. Select the Nozzle for Cold Pull
- From the U1 touchscreen Home Screen, tap
Control>Toolheads.
- On the left side of the Toolheads screen, select the nozzle of the toolhead you want to clean by cold pull.
- Tap
Attach Toolheadand you can observe the machine picking up the corresponding toolhead.
¶ 2. Heat the Nozzle to 230°C
- On the touchscreen Toolheads screen, tap
Nozzle Temp..
- On the Nozzle Temp. screen, tap the temperature display area; set the target temperature to 230°C, and tap
Done.
- Wait for the nozzle to heat up to 230°C.
¶ 3. Extrude at High Temperature
- After the nozzle reaches 230°C, return to the Toolheads screen.
- Tap
EXTRUDE, and wait for the toolhead to extrude the filament.
Example: The toolhead extruded filament:
¶ 4. Cool the Nozzle to 70°C
- On the Toolheads screen, tap
Detach Toolhead.
- After the toolhead is returned, lower the nozzle temperature to 70°C.
¶ 5. Cold Pull
- After the nozzle temperature reaches 70°C, press the round clamp on the toolhead while pulling out the filament tube from the toolhead.
- Keep holding the orange lever on the toolhead while pinching the filament at the top of the toolhead, and pull the filament out steadily at a constant speed.
Note: Normally, moderate force should be sufficient to loosen and pull out the filament. Do not use excessive force to pull it out forcibly.
If you find the filament difficult to pull out, reheat the nozzle to 230°C, perform a high-temperature extrusion, cool the nozzle to 70°C, and then try pulling it out again.
Example: After a successful cold pull, you can see that the tip shape matches the internal shape of the nozzle, presenting a "funnel shape":
¶ 6. Reload Filament
- After the cold pull, simply rotate the filament holder to retract the filament.
During this process, be careful to avoid tangling the filament.
- After retracting the filament, cut off the tip that was deformed by the cold pull, and then reload the filament for normal use.
For reloading, you can refer to the U1 Video Guide: Loading & Unloading Filament.