https://support.makerbot.com/s/article/1667337897165
Tip: This method can be used as corrective maintenance when the nozzle is clogged. It is also recommended to perform this process as a preventive action when switching between materials that have very different printing temperatures.
Instructions
To clean the nozzle, perform the following steps:
Preparation
| 1. Unload material | Remove the material from the printer by going to Material → Change. Wait for the material to unload. After this, select Cancel instead of loading a new spool. |
| 2. Place print head | Manually place the print head in the front-right corner of the printer. This gives you easy access to the print head and prevents damage to the print head shafts. |
| 3. Remove Bowden tube | Remove the clamp clip from the print head. Push down on the white tube coupling collet and pull the Bowden tube up and out of the print head. |
| 4. Cut some filament | Cut off a length of filament, approximately 20 cm. You can use PLA for this, but other (non-flexible) materials will also work. Ultimaker also offers pre-cut cleaning filament. |
| 5. Heat up nozzle | Go to Maintenance → Advanced → Heatup nozzle to manually select the nozzle temperature. For PLA, choose 200 - 220 °C. For ABS, cleaning filament, or other more high-temperature materials, choose 240 - 260 °C. |
| Remove the clamp clip | Pull out the Bowden tube |
Cleaning
| 1. Insert filament | When the nozzle has reached its target temperature, insert the piece of filament into the print head. It is recommended to hold the filament with pliers. |
| 2. Hot pull | Apply some pressure to the filament and immediately pull it out again. This removes the majority of carbonized material. |
| 3. Cut and repeat | Cut off the tip of the filament that you have just pulled out. Repeat steps 2 and 3 several times until the tip comes out fairly clean. Insert the filament into the print head again and keep it there. |
| 4. Lower nozzle temperature | Via the Heatup nozzle menu, lower the nozzle temperature. For PLA, choose 80 - 100 °C. For ABS, cleaning filament, or other more high-temperature materials, choose 140 - 160 °C. Continue to apply pressure to the filament until about 50 °C above the target temperature. |
| 5. Cold pull | When the nozzle has reached the target temperature, pull the material out of the print head with a quick, firm pull. Make sure to use pliers for this. |
| 6. Inspect | Check the tip of the filament. It should come out clean and cone-shaped (like the inside of the nozzle). If it is not clean, raise the temperature again and repeat steps 3 - 6. |
Examples:
| Too much carbonized material, repeat the cleaning process | Almost clean, perform one more cold pull | The tip of the filament is completely clean, proceed to reassembly |
Reassembly
| 1. Insert Bowden tube | Push the Bowden tube back into the print head. Make sure it is fully inserted. Secure it with the clamp clip. |
| 2. Load material | Via the Maintenance → Advanced menu, select Insert material. Follow the steps on the display to reload your filament. More information on loading filament can be found on this page. |
| 3. Check extrusion | If the hot and cold pulls were performed correctly, filament should be flowing smoothly from the nozzle again. |
Clean the outside of the nozzle
The method described above cleans the internal geometry of the nozzle. If some burnt or carbonized material is stuck to the outside of the nozzle, this can also degrade your print quality. Pieces could get stuck in your printed object.
To clean the outside of the nozzle, simply raise the nozzle temperature via Maintenance → Advanced → Heatup nozzle. Remove any material stuck to the nozzle with tweezers. When you are finished, set the target temperature back to 0 °C.
Caution: The nozzle will become hot. Do not touch the nozzle with your hands during this process and be careful while cleaning.