When the nozzle of your Ultimaker is clogged or blocked, this will prevent the material (or hardly any) from being extruded. This blockage is usually caused by dirt or carbonized material in the hot end.
Several methods can be applied to remove the blockage. This page describes which steps must be taken to clean the nozzle and continue printing again.
Manually extruding material
The easiest way to check the severity of the blockage is by manually extruding some material. In some cases, the nozzle is clogged with just a tiny particle that will come out when some extra pressure is applied. Take the following steps to do this:
- Ultimaker 3 (Extended): Go to ‘Material/PrintCore’ → ‘Material 1’ or 'Material '2' and select 'Move'. Wait for the print core to heat up. When the temperature is reached, rotate the button at the front of the Ultimaker to forward the material. You can put some extra force on it by pushing the material into the feeder while doing this.
- Ultimaker 2(+) Family: Go to ‘Advanced’ → ‘Move material’ and wait for the nozzle to heat up. When the temperature is reached, rotate the button at the front of the Ultimaker to forward the material. You can put some extra force on it by pushing the material into the feeder while doing this.
- Ultimaker Original(+): Go to ‘Control’ → ‘Temperature’ → ‘Nozzle’ and set it to the temperature that is required for the material you’re using. Manually extrude the material by rotating the wooden gear of the feeder and push the filament to apply some extra pressure if necessary.
Now check if material is being extruded from the nozzle. If you manage to achieve proper extrusion after manually pushing the filament through, there’s a big chance that the blockage has been cleared. Start a new print to check if it has been resolved completely, and if not, follow the next steps on this page.
Applying the Atomic Method to unclog
When the nozzle is clogged with dirt or carbonized material that is bigger than the nozzle diameter, it is impossible to push it through the nozzle. In this case, the only way to remove the dirt is by taking it out from the top. This can be done by applying the Atomic Method (Ultimaker 2(+) Family) or applying hot and cold pulls (Ultimaker 3), which are both simple yet very effective approaches. With these methods you basically let all the dirt or carbonized material stick to a fresh piece of material, after which you can pull it out.
Unclogging by using a needle
Sometimes it’s possible to unclog the nozzle with a needle. To do that, you must heat up the nozzle and insert the needle into the nozzle from the bottom side. It is important that the needle is thinner than the nozzle diameter; for example, you could use an acupuncture needle. Be careful not to push the needle against the sides as this might damage the nozzle on the inside. Simply insert it and take it out and check if any residue comes out of the nozzle.
Caution: Be careful not to burn your fingers as the nozzle and residue can be hot. You can use a cloth to protect your fingers from the residue.
Replacing the nozzle
If none of the above methods helps to resolve the clogged nozzle, there’s a chance that the nozzle will need to be replaced. For 3D printers with a separate nozzle (or Olsson Block), this is very easy. You can just unscrew the nozzle from the hot end (after removing the material) and attach the new nozzle to it. If you have an Ultimaker 3 (Extended) you can replace the print core, although this doesn't have to be necessary if you clean it properly. Take a look at these pages for detailed instructions: