I have a new Flashforge Creator 3 with independent dual extruders. Setup went seamlessly, I was able to print with both extruders separately and combined almost perfectly out of the box. As long as I use multiple processes and only one extruder per process, it's working like a charm. I came across a very weird and specific issue though when I tried to print supports with a different material.
When I specify to use the second extruder in the same process (for supports or infill), i get a consistent layer shift as soon as the second extruder starts to be involved. The shift happens always at layer change and for both extruders exactly the same. Meaning they'll print perfectly aligned to each other but shifted along the Y-axis (towards the back of the build plate) by about 0.5mm. This keeps adding up with every layer.
I initially tried printing PVA supports. When troubleshooting I tried using the second extruder with PLA for infill. The first layers, when only one extruder is needed, come out perfect. As soon as the infill starts and the second extruder comes into play, the shift starts happening with every additional layer.
Here are some pictures for reference:
Good print with multiple processes:
Layer shift with supports using 2nd extruder:
Layer shift with infill using 2nd extruder:
Does anyone have an idea how this very specific issue is caused and how it can be fixed? Any help is greatly appreciated, thanks!