Gap at z-seam
Hi everyone,
Just a quick heads-up: I’ve been into 3D printing for eight years now. Over this time, I’ve had the chance to learn a lot and developed a solid understanding of the physics behind it. However, I’ve now run into a problem that I just can’t seem to solve.
For context:
I’m printing on a Prusa MK4S and slicing with OrcaSlicer.
Whenever I switch to a new filament or nozzle, I fully recalibrate everything from scratch—temperature, flow rate/extrusion multiplier, Pressure Advance, and so on. Thanks to this, I’ve always achieved very high-quality prints.
Up until now, I’ve been printing PETG with a 0.4mm nozzle. Recently, I bought and installed a hardened 0.6mm nozzle for PETG-CF and recalibrated everything.
While the dimensional accuracy and surface quality are absolutely perfect, the Z-seam is completely ruined.
As soon as a new layer starts and the printer begins extruding, it takes a brief moment for the filament to actually come out of the nozzle. This results in missing sections. The layer then closes perfectly before moving on to the second wall/outer wall. This second line starts and ends almost flawlessly. However, if the print head travels across the bed to start at a different location, the seam there is broken as well due to missing filament.
I’m completely at a loss as to which settings to adjust next.
What I did find out: if I reduce the retraction distance from the default 1mm (picture 1) down to 0.5mm (picture 2), the gap where filament is missing gets smaller. If I lower it any further, I start getting stringing issues. But even then, there is still a persistent gap left at the Z-seam.
Could you please help me out? 🤷🏻♂️
I am printing at 100 mm/s and 3000 mm/s².
