OMG my Print has failed!

There seems to be a number of failed prints out there where, the failed print

attaches to the extruder and becomes a mass of hardened filament,

(see image 1.1. for the worst case of this we have ever seen)


This can occur when the print was not correctly adhered to the bed (see our article on Levelling your bed), and the operator walks away and does not come back for an extended period of time. What happens is, whilst the operator is away from the machine, the print lifts off the bed, and gets caught on the filament fan nozzle; because the extruder is still extruding, the mass becomes larger and can end up like image 1.1 or 1.2.


We always recommend that the operator stays for the first 1cm of a print (especially large prints), and novice printers never leave the printer unattended.


Can I Fix This?

Yes we can help you fix this.  What we need to determine is what is engulfed in the mass. Is the thermocable engulfed ? See image 1.1


Has the mass pushed its way into other parts of the extruder?


If yes contact Bilby CNC tech support through the ticketing system! Please attach photos for our reference and determination on how to proceed.


If the mass is restricted in its attachment, and attached only to the heater block (image 1.3). You can fix it, following the below steps.


How do I fix this?

(only where mass is small and does not engulf parts/wires)

Approach Slowly and Carefully

1. Unscrew and remove the filament fan nozzle, to avoid breakage (only 2 screws. The filament fan is the big one on the left side of the extruder)

2. Run Preheat 

    This helps to soften the plastic so it can be removed easier.

3. CAREFULLY and GENTLY! Try and Loosen off the melted  filament using a levering/wobbling technique, you may need to let it cool and warm it again a few times to create shrinking points around all parts.

4. DO NOT JUST PULL it all the way off!!

  Ensure NO Cables are engulfed in the mass!

  If no cables are in the mass, pull the mass away.

  You may need to cut some of the mass, to pull it off cleanly.

7. Clean off any remaining filament off with acetone.


After Cleaning:

a) You may need to replace the ceramic tape that surrounds the heater block

b) Check the thermocable is not damaged. See article Thermocable  Function, Error and Repair on the support section of our site


I have tried this and I am still having troubles.

Please contact Bilby CNC for further assistance via the ticketing system, please attach photographs for our reference.


For your information, this situation is not covered by warranty, as it has occurred through miss use in that the print was unattended and it is miss levelling that causes the print to come off the bed. Costs of repair will be your responsibility.