Layer lines starting at the seam, but disperse after a while

[Darren_Lynch]

I have some ridges started appearing on my P1s, I thought initially it was wet filament, but after drying, trying different filaments and machines I conclude:

1. This is only on he P1s not the A1 mini
2. Not the filament

Here is what I am seeing on a gridfinity example:

The technical stuff I am using:

• 0.4 nozzle (admittedly, getting a bit old?)
• PLA (matte PLA from eSun or Polymaker, or basic PLA from Bambu)
• 0.1mm layer height
• Brim and raft (this really sticks to the floor, as I modified the box in a way that promotes warping)
• Smooth pei plate (official Bambu)
• Tuned settings for the PLA (sun matte) in the image (flow rate and k value)

Any thoughts?

[JonRaymond]

Have you performed the belt tensioning and rod cleaning maintenance?

Belt tensioning procedure

[Darren_Lynch]

Not recently, thanks for the suggestion, I will give it a try.

Best,
Darren

[Darren_Lynch]

Hi @JonRaymond unfortunately no real change:

Any other suggestions?

Best,
Darren

[JonRaymond]

I may be an issue with your K value as the greatest problem originates at the seem. If you move the seem to another section does the issue follow it? Is it only an issue on this part?

[Darren_Lynch]

Ok then, I’ll calibrate K again. I would say it’s most visible on this part, I think because it lies on a smooth corner. I have a part that is almost the same in shapes, but joined, and I think because the seam was hidden at a sharp edge it’s basically invisible.

I’ll do this in 2, so I know what worked:

1. recalibrate k and print
2. (if 1 doesn’t fix) move seam and run again

Thank you.

[JonRaymond]

How hot are you printing the filament? Also does printing in silent mode (%50 speed) have any effect?

[Darren_Lynch]

The test above was at 200 degrees, the previous image was 220 deg C I reduced temp incase that was the issue.

I’ll test reduced speed as no.3.

Thanks again

[Darren_Lynch]

I am starting to think your onto something wrt speed:

Still waiting for the next test to finish.

[Darren_Lynch]

Ok, in the end I printed 4 more samples, and finally figured out it was the wall order. I was using outer/inner, switching to inner/outer gives a better surface finish. To me this is counter intuitive, but I don’t actually care as long as I know.

Does this make sense? I assume I don’t have another underlying issue if this is the fix.

[JonRaymond]

Good job working through the issue and sorting it out. Thanks for posting your final fix.