Extruder blob

Updated 4 weeks ago ​by Tomáš Chvalina

Extruder blob is one of the worst printing problems you might face with your 3D printer. Unlike the spaghetti monster, this issue occurs earlier in the process, usually during the initial 5 minutes of the print. The first layer becomes detached and covers the nozzle, while the extruder keeps extruding and the blob grows and grows, leaving you with a non-working printer.

Don’t worry, it is really easy to prevent this situation from happening. However, it is quite tricky to clear it after it happens. Just to make it a bit easier for you, we have prepared a short video where we show you how to remove it

How to clear the extruder blob

  1. Keep in mind what can be entangled in the mass/blob that has formed around the hot end, which are the leads for the thermistor and heater cartridge. The leads for the thermistor are the ones to be most careful with as they are thin gauged wires.
  2. We now want to preheat just the nozzle which you can do in the LCD Menu - Settings - Temperature - Nozzle. Depending on the material you are using, it will require a different temperature. In any case, you want to have significantly hotter than your print temperatures. For example, if the blob is made of:
    1. PLA: preheat to 250°C
    2. ABS/PETG: preheat to 280°C
  3. Would any of the leads be broken at the very start? You can be given MINTEMP or Preheat error. Then you are left with one last option, which is the heat gun. Work very carefully with it and only clear bits of plastic at once.
  4. Once the hotend is up to the set temperature, using a pair of pliers, carefully work the newly molten areas of the blob-free. Again, be very cautious around the leads coming from the hot end, in particular, the thermistor leads.
  5. Work slowly and cautiously around the mass, no need to rush it. Doing so will likely result in having to purchase replacement parts.

Unfortunately, some of the blobs are not really easy to clear. Especially the ABS/PETG ones. Would you not be successful you can find spare parts in 3D Printer parts at our e-shop (remember that you must be log into your e-shop account). 

How to prevent extruder blob from happening:

  1. Check the first layer – Since an improper first layer is the source of extruder blob in most of the cases, make 100% sure that the first layer is sticking properly to the entire print surface. You can refer to the First layer not sticking.
  2. Monitor the print for 5–10 minutes – Let the printer run for 10 minutes and check the progress. We recommend doing this every time. If you observe any issues, restart the print. If everything seems running okay, then you can just let your printer finish the job. After the initial 10 minutes, it is unlikely your printer would create an extruder blob.

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