I tried to do a search but didn’t seem to come up anything along these lines but perhaps I’m just not finding it. I’m still relatively new to 3D printing having had a printer for about 6 months now so this is probably a newbie question I hope I won’t catch flack for.
I printed off a gridfinity bin on my H2C for some of my tools and you’ll see in the included photo that the top surface numerous pronounced lines showing including some going the opposite direction from the layer underneath. I’ve noticed this happen on a number of my prints and obviously it’s much more noticeable when using darker filaments like black. Part of what I think may be happening is as it’s laying down the layer it doesn’t necessarily start in one corner and continue all the way until it reaches the other corner but will bounce around some especially when it gets to the cut outs or say a magnet or screw hole. Then when it goes back to fill in, there becomes almost a seam.
I’m sure there are settings in Bambu Studio that I should be looking to change and any suggestions are greatly appreciated.
Thank you for your suggestion. I should’ve have mentioned that I did complete the basics of drying the filament and running the pressure advance and flow rate calibrations. However, I can certainly redo those calibrations to make sure they are correct. I also generally slow down the speed for the top surface.
I should also mention the black filament used is Bambu PETG HF.
Two separate things seem to be going on in your photo, and they have different fixes.
The seams where it jumps around the cutouts and magnet holes come from the order the top layer gets laid down. Setting Strength → Top surface pattern to Monotonic line keeps every top line going in the same direction and order, so there’s no second pass to leave a seam. A 3MF from MakerWorld can carry its own process settings, so check what that file actually uses.
The lines running the other way are most likely the solid layer underneath showing through. That’s what the 2.8.3 change mentioned above targets. If you’d rather not run the beta, adding one or two top shell layers usually helps with the same thing.
Ironing (Quality → Ironing → Top surfaces) can smooth out what’s left. With PETG HF I’d try it on a small test piece first; 2.8.3 also adds an Archimedean spiral ironing pattern that’s meant for surfaces broken up by holes like magnet pockets.
Thank you very much for your reply and suggestions. I do use Monotonic line for the top surface which is part of the reason why I was struggling to figure out a solution. However, the change in the 2.8.3 that you both referenced looks like it could be helpful. I will download the beta and give that a try. Once downloaded, I think I’ll also rerun the calibrations and then may add an additional top shell layer per your suggestion. I did start trying to look into ironing at one point and printing off a couple tests but I need to do a deep dive and really educate myself on the process. Especially with the new Archimedean pattern.
Thanks again to everyone who has replied and offer suggestions so far. Much appreciated.
