I’m experiencing a strange surface artifact when printing with the Concentric top surface pattern with PETG HF with my bambu H2D.
As you can see in the attached photo, the top surface develops a very noticeable irregular pattern/wavy distortion around the inner circular area. The defect follows the concentric top lines and creates an uneven finish.
The issue occurs consistently when using Concentric as the top surface pattern.
It happens even if I move the model to a completely different location on the build plate, so it doesn’t seem to be related to a specific area of the bed.
If I switch the top surface pattern to Rectilinear, Monotonic, or Grid, the problem disappears and the top surface looks normal.
The rest of the print quality is generally good.
The artifact appears to be related specifically to the way concentric top layers are generated or printed.
Has anyone seen something similar before? I can’t find any on the web.
Any suggestions or settings to check would be greatly appreciated.
Thanks!
Yes. I’ve seen that. The problem with concentric is it’s concentric from everything. Where one set of circles intersect another, you get the corner bulging problem as the nozzle changes directions.
You can mitigate this by doing the flow compensation calibrations, but the real answer in this one is to use a pattern that nets you the surface you want.
I have a viking ship model where concentric causes the distortions you see here, but there they are actually kind of cool looking.
If you want smooth, the Hilbert Curve is a good one to try out.
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