Clicking Extruder, under-extrusion and clogging - MINI
The extruder clicking is the sound of the extruder-motor snapping back, unable to push the filament through the hotend, having clogged.
There are 3 main things to check in case of the extruder clicking or under-extrusion, on the MINI:
- A clogged nozzle
- Hotend PTFE-tube and Heatbreak.
A clogged nozzle
- Remove the bowden-tube, between extruder and the heat-sink, and check if filament can be pushed through the nozzle by hand, when pre-heated.
- Use the supplied acupuncture-needle to loosen the clog.
- Do 1-3 cold pulls: https://help.prusa3d.com/article/lnbcnhg76k-cold-pull
Make sure that filament can pass through the bowden-tube without much force. Too much tension on the idler can deform the filament and cause greater resistance.
You can adjust the tension of the idler on the springed-screw, located right bellow the PTFE-tube, circled in the picture below. With the filament removed, the screw head should be level/flush with the plastic part.
Hotend PTFE-tube and Heat-break.
- Remove the bowden-tube and fitting from the heat-sink and carefully remove the PTFE-tube inside the hotend.
- Check that there is no filament in the bottom of the heat-break. Use a light from the top - It should be clean and you should see only metal inside.
If there is any filament visible try the following steps to clear it:
- Pre-heat the nozzle and push filament in by hand, (without the hotend-PTFE) and quickly pull it out. Residual filament should stick to the filament - repeat if necessary.
Once clean, the proper way to re-install the hotend-PTFE is as follows :
- Push the PTFE-tube into the heat-break, all the way down.
- Loosen the three grub-screws on side of the heatsink and try to push nozzle upwards. You will see the PTFE-tube moving upwards.
- Re-attach the bowden-fitting to the heat-sink, tighten it, then loosen it a 1/3 turn.
- Gently push the nozzle against the fitting until it stops on the PTFE-tube. Then tighten all three grub screws.
- Tighten the fitting for the bowden-tube properly (the 1/3 turn from step 3).