The “blob of death” is a common issue in 3D printing, where the extruder nozzle leaves a blob of filament, instead of producing a clean and continuous flow.
This can be caused by various factors, including a clogged nozzle, incorrect extruder temperature, or incorrect filament flow rate.
To fix the 3D printer blob of death, you want to heat up your nozzle to the temperature that your last printed at, then leave it for a few minutes to heat up and gently scrape and pick off the filament blob with tweezers or pliers. Make sure to be careful to not damage the delicate wires. You can also use a hairdryer
Keep on reading to learn the details on how to fix the blob of death.
How to Fix 3D Printer Blob of Death
Here are some of the methods to fix the 3D printer blob of death:
- Heat up nozzle & scrape off blob
- Replace the hotend
- Soak it in acetone & scrape off blob
Heat Up Nozzle & Scrape Off Blob
The main method in order to fix the 3D printer blob of death is to heat up the nozzle and scrape off the blob.
To do that first heat the hotend to the print temperature or the minimum filament temperature. The extruded material will become soft and can be scraped off, but be cautious not to damage the hotend or thermistor wires.
One user suggests scraping the blob off with an old toothbrush or a nozzle brush, which you can find on Nozzle Cleaning Kits over at Amazon.
This is the most suggested way to fix a blob of death by users, as many of them were able to get rid of their blobs by heating up and cleaning the nozzle. A hairdryer or similar heating tool can be used to soften the filament.
Check out the video below for detailed instructions on how to remove a blob from your 3D printer.
Additionally, check for a faulty or loose seal between the hotend heat block and the heat brake. After cleaning, ensure that everything is properly positioned and tightened, but not over-tightened.
Tightening while cold may cause the material to become loose during heating due to expansion. When everything is tightened correctly, your hotend should be back to normal operation.
Replace the Hotend
There is a chance that your hotend may have been damaged by the blob of death and you may need to replace it.
It’s important to check if none of the wiring has been affected and if you’re able to successfully remove all the filament that was stuck on it.
One user was trying to get rid of a giant blob of death that showed up because of the low temperatures of his printing environment and pre-heated his nozzle to 215°C.
He was able to take off the blob with the help of small pliers and everything was working properly again.
Another user did not have the same luck and unfortunately, the blob ended up damaging the wiring of the hotend and he decided to get a new one.
Be aware that you may need different replacement parts as the blob of death can damage multiple areas of your printer, especially if it gets too big.
Check out the video below for detailed instructions on how to replace a hotend.
Soak it in Acetone & Scrape off Blob
Another method you can try in order to remove the blob of death that has been formed on your 3D printer is by soaking your hotend in acetone and then scraping off the blob.
But be aware that this method only works if you are printing with ABS filament, as it will smooth out when in contact with acetone.
That means you can just soak your hotend in acetone for a few hours and then scrape off the blob as the filament will be a lot softer.
One user was able to salvage his hotend after soaking it in acetone for 36 hours and scrapping the blob off, he’ll just need to replace the heater, the thermistor, and a heat screw.
How to Prevent the 3D Printer Blob of Death
Here are some ways to prevent getting a 3D printer blob of death:
- Improve bed adhesion
- Check filament flow rate
- Get a silicone sock
- Check retraction distance
- Adjust nozzle height and level the bed
Improve Bed Adhesion
The first step you can try in order to prevent getting the 3D printer blob of death is improving the bed adhesion.
This is because the bed not adhering properly is the main cause of a blob of death forming during 3D prints.
One user stated that this is pretty common to happen if you haven’t been checking how good your printer’s bed adhesion is and have the habit of leaving the printing unattended.
Users recommend using glue sticks to increase adhesion, especially when printing difficult filaments such as ABS and also making sure the bed stays clean and you wipe it with alcohol regularly.
Another user suggests running a first-layer calibration test if you own a Prusa 3D printer and are experiencing blobs of death due to poor bed adhesion. You can find that function on the LCD screen and it will help you fix the problem.
It’s important to note that different filaments may require more or less adhesion than others, so be sure to check the manufacturer’s specifications for each filament you use.
Check out the video below for more information about bed adhesion.
Check Filament Flow Rate
Another step you can try in order to prevent getting the 3D printer blob of death is checking the filament flow rate.
It should be adjusted to ensure a consistent feeding pace into the extruder. Inconsistent flow rates can cause filament compression, resulting in blobs and strings.
The recommended flow rate varies depending on the filament type, that’s why it’s important to have a good knowledge of the filament you are printing.
Make sure to check your current flow rate setting and the recommended range and adjust accordingly.
One user got an awful blob of death when printing with a high flow rate and was recommended by other users to slow the filament flow rate down in order to avoid blobs of death.
A slower flow rate usually leads to better print quality, while a faster rate speeds up the process but may compromise quality.
Check out the video below for detailed instructions on how to calibrate your filament flow rate.
Get a Silicone Sock
Getting a silicone sock is one of the main ways to avoid being a victim of a blob of death.
Silicon socks are protective covers for 3D printer hotends. They are made from silicone material and designed to fit over the heating block and nozzle of a 3D printer’s hotend.
Their purpose is to insulate the hotend, which helps to reduce the amount of heat that is lost during printing and also helps to prevent heat from going into the surrounding environment.
Additionally, silicon socks can also help to prevent the filament from adhering to the hotend, which can cause clogs and other printing issues.
Using a silicon sock can make removing filament blobs and cleaning the hotend easier and more efficient.
You can find Hotend Silicon Socks over at Amazon for great prices and good reviews.
Check out the video below for more information about silicon socks.
Check Retraction Distance
Checking the retraction distance is another way to prevent a 3D printer blob of death from showing up.
If your filament is retracting too far or not far enough, it can cause blobs and strings to form. You can adjust the retraction distance in your slicer to the recommended value for your specific filament.
The recommended retraction distance will vary depending on the type of extruder and filament you’re using. Bowden extruders usually work well with a 35-55mm/s retraction speed and 3-5mm retraction distance.
Direct drive extruders usually work well with 20-40mm retraction speed and 1-2mm retraction distance.
One user stated that blobs of death may form when the filament drips while moving over the print, which can be easily fixed by increasing the retraction distance.
In general, a longer retraction distance will help prevent the filament from oozing, while a shorter retraction distance may cause the filament to leak out of the nozzle.
Check out the video below for more information on retraction settings.
Adjust Nozzle Height and Level the Bed
Another way to prevent a 3D printer blob of death is by checking the nozzle height and leveling the bed. An incorrect nozzle height or an uneven bed can cause blobs and strings to form.
One user had his nozzle too close to the bed, resulting in a blob of death being formed. He was able to solve this after users recommended checking his nozzle height and adjusting it accordingly.
Before starting a print, it’s also important to ensure that the bed is level. This is important because an uneven bed can cause the nozzle to scrape against the build plate, which can result in blobs and strings.
If the bed is not level, there are different ways in which you can try to properly level it. I wrote an article about How to Level Your 3D Printer Bed.
It’s important to note that the nozzle height and bed level are closely related, so it’s important to check both of these settings whenever you’re trying to resolve a blob of death problem.
A correctly set nozzle height and level bed will help ensure that the filament is flowing smoothly and consistently, which will result in better print quality.
Check out the video below for more information on nozzle height and bed leveling.
Once you’ve taken these precautions and done your calibrations, you should no longer experience the blob of death with your 3D prints.