I have trouble fixing the terrible seams I'm getting. I've followed Elli's print tuning guide and calibrated extruder, tuned PA (it's now 0.035) and extrusion multiplier.
I've tried adjusting both retraction length and speed, but it doesn't seem to have much impact. I'm not using "wipe on retract" or "retract on layer change", I only retract if travel distance is longer than 3mm. Retract is 0.3mm @35mm/s.
I've tried reducing PA smooth time too, but this also doesn't seem to have a noticable impact.
I've tried reducing seam gap from the default 10% in Orca all the way down to 0%, but the bad seams persist.
I've tried with "wipe on loops" both disabled and enabled with no difference.
I've tried with both arachne and classic wall generator, no difference.
I've tried different wall orders, inner/outer, inner/outer/inner and outer/inner, all with the same bad seams.
Filament in the picture is matte PLA, it is without doubt dry and generally prints well aside from the seams. It's stored vacuum sealed with silica, and I use a filament dryer to dry if I suspect wet filament.
I'm running out of ideas for where to tweak to get a decent result.
Disclaimer: I'm not into 3d printing. I'm just a wannabe with not enough time on my hands, so take this post with a bucket of salt. I have, on the other hand, worked a lot with automated machinery.
But if I were to make a guess, I would suspect some slack in either the X or Y direction, resulting in inaccuracy when the nozzle changes direction. This should in theory be less visible when the nozzle is not making sharp turns.
Are your belts tight? Any gears with poorly meshed teeth?
Also, are you able to turn the print (and the seam) 45 and 90 degrees? Do they show up just as ugly? If not, the issue is mechanically limited to one axis.
Actually yeah, you might be on to something there. OP could try adjusting belt tension.
If you do end up adjusting belt tension though, make sure to recalibrate your e-steps after.
It's worth a look but I really suspect PA to be the culprit here. The differences between the layers are probably explained by the feed rate after or before the turn due to different path planning.
No, that issue would show a problem with layer stacking as well, which is not the problem here.