Weird diagonal artifacts on new A1

Bambu Lab A1 Series Troubleshooting
1

Hi to everyone,

I have a strange issue with my new A1 replacement.
I’m in printing for a while with other printers, never had this kind of issue on a simple model like that.
I have just print an empty cube with 2 different PLA spools. One is a new Bambulab PLA basic purple but same issue.
What tests I have made without success :

  • change filament spool
  • check all axis, lubrification,belts etc…
  • full calibration
  • change seam position
  • change cube position on plate
    The weird pattern always occurs along X axis in one side when the hotend moves to the left as you can see on photos, the opposite side has a very light pattern almost invisible in some case, more visible on gray PLA than on purple.

IMG_20250313_202645
IMG_20250313_202645540×1200 88.9 KB

IMG_20250313_202701
IMG_20250313_2027011200×888 213 KB

IMG_20250313_202711
IMG_20250313_2027111200×983 194 KB

IMG_20250314_083543
IMG_20250314_0835431200×540 77.7 KB

IMG_20250314_144652
IMG_20250314_1446521200×927 161 KB

If someone has an idea of the issue and a fix, it will great.
Thank in advance

2

This comes from overextrusion and is diagonal because each layer shifts the thick spot forward slightly. So flow rate calibration would be the thing to try.

2 Likes
3

I don’t think so because

  • if I move the object on the plate, the pattern is different ( you can see on the last photo, the pattern is more regular than on previous pics)
  • it happens always on x side never on y side even if I change seam / retraction position. The seam is on a corner.
  • it happens with different filaments with exaclty the same pattern.
    For me, it seems to be a resonance or interference on x axis or hotend, but not the belt as it is not regular.
4

Try slowing down the outer wall. Also, you need to tune the pressure advance.

5

I am curious then, did you happen to measure the x vs y dimensions?

6

I will make it after resolving this issue with a cross calibration.
In fact, the main problem on Bambu printers is the accuracy in x/y dimensions.
I think to swap the X gantry of my old a1 to the new one to check if the problem comes from x motor/driver or hotend.

7

I can but if it was that, when I move the seams/retraction to other corner, it should change the side.

1 Like
8

If the x axis was fine on the old one yes that would def be a thing to try.