Help - catastrophic failure
After a few years of really excellent prints and no trouble, I awoke this morning to a bad failure. Filament melted all over the extruder. How do I begin to repair this? If this is even repairable and I have to take apart the extruder, is there a step by step? It’s been a long time since I assembled the printer. Thank you!
RE: Help - catastrophic failure
search for "blob-of-doom", probably quite a few stories to be found. I remember "hot air pistol" was mentioned at some point.
You can probably print a new fan shroud in a material that works with zero print fan cooling e.g. ABS or ASA.
RE: Help - catastrophic failure
If you can remove the plastic from the extruder without damaging any wires you will save the extruder. A heat gun used for melting frozen plumbing is what I have used. Pre heat the hot end if that's still possible and carefully try to remove the plastic. Be patient with it. If this doesn't work you can replace the extruder or even just the hot end fairly easily.
As @mnentwig says, you have a first class blob of doom. Search for blob of doom to see how others have dealt with them.
Before doing anything, look at pictures of a clean extruder and note the position of the rather delicate wires that are currently hidden, if you damage them you will have to buy replacement parts as broken wires can't be rejoined.
You have probably damaged your fan shroud and will need a replacement.
To remove it:
Raise the nozzle temperature to the printing temperature for the filament in question and allow it to heat for several minutes.
If you are lucky you will be able to prise the blob open - more likely you will need to add heat from outside with a heat gun to aid the softening, sometimes it's worth using a soldering iron to carve chunks off the mass.
Use needle nosed pliers to prise this away; remove it in parts if it won't release the wires.
Once you have the worst removed you decide whether you need to disassemble the extruder to get at all the blob or perhaps you can clean up in situ.
After the cleanup there will be overcooked filament inside the nozzle so at least a purge and probably a cold-pull will be necessary.
Cheerio,
RE: Help - catastrophic failure
Thanks all - as predicted, the fan shroud broke off with the blob but everything else looks ok I think. Off to try printing a new fan shroud.