The PTFE coupler is a consumable part that can wear over time due to the heat and pressure on the hot end. Therefore it is recommended to replace it when you notice that it has deformed.
Important: Make sure filament is removed, the Ultimaker is turned off and power supply disconnected before you start the replacement.
Note: The instructions are the same for the Ultimaker 2 Go, Ultimaker 2 and Ultimaker 2 Extended.
1. Removing the bowden tube
- Manually move the print head towards to center of the Ultimaker for easier access.
- Remove the (blue or red) clamp clip.
- Press down the tube coupling collet and pull the bowden tube out of the print head.
2. Loosening the print head housing
- Put some tape (can be any tape) around the print head housing so it doesn’t fall apart later on.
- Loosen the 4 thumbscrews that go from top to bottom through the print head. Now you will see 2 parts: the print head housing and the hot end part.
3. Remove the PTFE coupler
- Remove the fan bracket; it’s attached with 2 screws on either side of the hot end.
- Loosen the 2 screws that are in the top aluminum plate, after which you can take out the spring and PTFE coupler.
You will probably notice that the PTFE coupler is a bit burned on the bottom and more important: has a brim on the inside. This brim can easily cause friction to the filament, thus leading to under extrusion. The below image clearly shows the difference between a new (left) and used (right) PTFE coupler.