In some case, mainly faulty filament retractions, some filament stays in the nozzle and clogs it.

The following procedure describes how to unclog the nozzle.

 

Tools needed

 

-  7mm (or 9/32") pipe wrench

- 1.5 mm (or 1/16") Allen key

- 2mm (or 5/64") Allen key

- Phillips screw driver

- pliers

 

1. Unscrew the head cover

Phillips screws in front 


2mm allen screws on the back


2. Take the head cover off the printing head

 

The mica plate is loose, this is normal as it is kept in place by the nozzle


3. Go to the /extrusion_control page, select the "temperature" tab and set the temperature of the clogged nozzle to 230°

for PLA, 250° for ABS by entering the temperature in the input field and clicking on the "SET" button

 


4. Wait until the nozzles reach the correct temperature (hitting the refresh button regularly)


5. Unscrew the nozzle with the above mentioned wrench (take care not to burn yourself)


6. Keep the nozzle in the wrench and push (strongly) the filament with the 1.5mm Allen key


7. Before reassembling the head, you need to clean up the filament path to the printing head

There are three possible cases which are descried in the pictures below showing half a printing head for better understanding


a. Filament is unbroken from head to cartridge

Go to the "Filament" tab on the /extrusion_control page and reverse 2000 mm at 1000mm/min by entering 2000

in the mm input field, 1000 in the mm/min input field and clicking on the "Reverse" button.


b. Filament is broken but accessible over the printing head


Go the "Gcode" tab on the /extrusion_control page and type in "M84" in the Verbatim One Line Gcode as in the picture below,

then click on the 'Send" button. This will unlock the stepper motors and allow you to easily pull out the remaining filament

by hand or with the pliers.



c. Filament is broken inside the printing head

Go to the "Filament" tab on the /extrusion_controlpage and extrude 50 mm at 100mm/min by entering 50

in the mm input field, 100 in the mm/min input field and clicking on the "Extrude" button. This should free the filament out of the head. 


7. Screw back carefully the nozzle in the printing head so that both nozzles are at the exact same level.

Be careful not to damage the threads while screwing the nozzle back.


8. Click on the "STOP" button in zim interface to stop the heating and wait for the head to cool off.


9. Reassemble the head cover