I received a reply from Snapmaker Support on how to properly perform a cold pull on the Snapmaker U1.
I asked how to best clean the nozzle when switching from printing PLA to TPU because I found that the first few layers of TPU can be contaminated by left over PLA in the nozzle.
I hope sharing this information will help others.
Here are the instructions (I applied some formatting and cleanup for clarity):
Snapmaker U1 Cold Pull Procedure
We recommend performing a cold pull cleaning on the hot end using PLA filament.
The detailed steps are as follows:
- First, load PLA filament and heat the nozzle to 230°C.
- Extrude some material to ensure smooth flow.
- Then lower the nozzle temperature to around 70°C and perform the cold pull
- During this process, please remove the 6 mm filament tube
- Release the driven extruder gear assembly (the yellow lever on the toolhead),
- Then slowly pull the filament out.
- Check whether the tip of the extracted filament is clean.
- If there is still residue, repeat the above steps as needed.
- It is recommended to perform this same cleaning procedure on all toolheads to ensure overall optimal condition.