If the Ultimaker 2+ Connect is not extruding the correct amount of material, or not extruding any material at all, there can be multiple causes for this. Try the following troubleshooting tips.
Check the profile settings
Underextrusion could be caused by incorrect or sub-optimal settings in the Ultimaker Cura profile, such as by trying to extrude too much material at too low temperatures. Before checking if the lack of extrusion is caused by a hardware problem, try one of the default printing profiles in Ultimaker Cura if you are using an Ultimaker or Marketplace material.
If you rely on custom print profiles, try adjusting some settings such as layer height, print speed, or print temperature. Read about all Ultimaker Cura custom settings here.
Clean the inside of the nozzle
If material does not flow consistently, the nozzle could be clogged with degraded material. In this case, the nozzle should be cleaned by performing the hot and cold pull method. You can use cleaning filament or PLA for this.
Cleaning filament can be used to clean the nozzle of the Ultimaker 2+ Connect by applying hot and cold pulls. Hot pulls are used to get the biggest parts of degraded material out of the nozzle and are especially necessary when the nozzle is clogged. With a cold pull, the remaining small particles will be pulled out, ensuring the nozzle is completely clean.
Follow the instructions on this page to correctly perform the hot and coll pull cleaning procedure.
Check the TFM coupler
The TFM coupler (the white part in the Ultimaker 2+ Connect hot end) can deform. The coupler is a consumable item that wears over time and slowly changes shape on the inside due to heat and pressure in the hot end. Eventually, this will cause friction to the material that has to pass through and causes under-extrusion.
Checking the condition of the TFM coupler requires disassembling the Ultimaker 2+ Connect print head. Follow the instructions on this page to learn how to do this.
Check the feeder
Extrusion problems can also be related to the feeder. Make sure that the feeder lever is fully closed after loading material. During printing, small filament particles can gather in the feeder and Bowden tube. Regularly clean the feeder and Bowden tube according to the maintenance instructions.
Additionally, check if the feeder tension is set correctly. For all Ultimaker materials, the tension indicator should be set to the middle mark. Use the hex screwdriver to turn the bolt in the top of the feeder to adjust the position of the tension indicator.
Tip: If you have an Air Manager, it must be uninstalled first in order to reach this bolt with the 2.0 mm hex screwdriver. Alternatively, use a smaller hex key.