Trouble with a circle becoming an oval

Flagship K Series Creality Flagship K2 Plus & CFS
1

Hello!nice to meet you!
I recently purchased a K2Plus!
Until now, I have been using the Bambu Lab X1C.
The K2Plus is an amazing machine that can create large objects.
I am experiencing the following issue with the K2Plus.

If anyone knows how to fix this, I would really appreciate your advice.
Please refer to the attached photos.
The hole shape is stretched downward, becoming an ellipse (towards the openable window side).

In the STL file, it is a perfect circle.
Does anyone know how to adjust this?

IMG_1362
IMG_13621364×2425 418 KB

IMG_1363
IMG_13631364×2425 338 KB

2

Try to calibrate printer again. Maybe belt tension drifts a bit.

3

@Yuki_Kojima ,
did you print a XY test?
YACS.stl (315,1 KB)

Here you can measure how exact the printer is, but this is normally not such a big difference that you see it. Anyhow, print is and measure AC, BD, AD where AC & BD should be nearly the same.
You can then include in a user print settings a corection in the start G-Code section by adding a line:

SET_SKEW XY=AC,BD,AD
# my own line is: SET_SKEW XY=141.055,141.4425,99.8325

In end print G-Code you should add also

SET_SKEW CLEAR=1

like shown here in my example:

2025-03-22_164425
2025-03-22_1644251538×751 99.9 KB

When you do manual belt adjustments you normally need to rerun the test and adjust values.

If the differenc3e between the two axes are > 5% I would

  1. Check if printer has latest FW (1.1.2.10)
  2. Reset printer to factory
  3. Rerun all calibration tests
  4. Check if you have newest profiles installed on CP6

2025-03-28_221518
2025-03-28_2215181886×1052 234 KB

2 Likes
4

Thank you.
I made the file you attached and measured it.
Everywhere, there was no misalignment and the dimensions were the same.

IMG_1433
IMG_14331920×3413 854 KB

However, the circle is not a perfect circle, but an ellipse…

5

Should I do a factory reset and re-calibrate?

6

If the fresh STL print generates a quality print with right dimensions you don’t need to re-calibrate but to be sure I would print another test:
HoleCompensation.3mf (78,2 KB)
If these print well (try to use arc fitting in the setting) then it is a print profile problem and not a printer problem.
On you part is the rest of the part with right dimensions and only the holes are oval?
Where did you get the part you print from? Was it an .stl and you use default print setting? Can you upload 3mf (it would include the setting) ?

7

thank you for reply.
I try your .3mf file.
Maybe they printed perfectly.
It is also possible to combine the holes.

I will send you the file where the problem occurs.
If possible, could you please check it?```model3D
{“src”:“https://forum.creality.com/uploads/default/original/3X/9/9/99b6bbdc2dad9d5bc54c9a9d20956213fc643f9c.stl”}

<!-- PLEASE DON'T DELETE THESE LINKS -->
<a href="https://forum.creality.com/uploads/default/original/3X/9/9/99b6bbdc2dad9d5bc54c9a9d20956213fc643f9c.stl" style="display: none;" tabindex="-1"></a>
<!-- PLEASE DON'T DELETE THESE LINKS -->
[リザーバーフイゴ（上）K2plus.stl|attachment](upload://lVOyCusQsls4sNWhK2b6iDmtxBa.stl) (248.3 KB)
![IMG_1581|690x388](upload://gueWaFtVDhMcXd81fP1one4PRJk.jpeg)
![IMG_1582|690x388](upload://eNF3fQTTNY0AtukrnKmwVSSGWnZ.jpeg)
8

Hi, Blender seems to show the .stl file as correct. It is perfect - not a single geometry error. Here are some photos:

K2Plus1
K2Plus11920×1032 292 KB

K2Plus2
K2Plus21920×1032 217 KB

K2Plus3
K2Plus31920×1032 219 KB

K2Plus4
K2Plus41920×1032 194 KB

1 Like
9

Yes, as @rdtsc mentioned the STL is good and the holes are true circles.

I wanted that you submit the 3mf file and not the stl file, in 3mf we can see also your slice/print settings you use.
The 3mf is created when you save a project in CP6 slicer. I save all my projects in 3mf because I may change some settings afterwards. If you (by accident) resized the print in one direction or using a bad hole compensation or convert holes to polygons for example then this can be seen only in the 3MF, it will include the STL as well.

10

Hello. Thank you for checking my files.（＾＾）

11

Hello.
Thank you for everything.
I have uploaded the file in .3mf format.
Please check it out.
I am using creality print6.

Untitled.3mf (62.7 KB)

Yesterday, I tried different print speeds. At the default speed of 100%, the perfect circle turned into an oval, but when I set the speed mode to 50%, the print did not turn into an oval.

In bambulad’s x1c, even at 100% speed
it never became elliptical, but in k2plus it does.
Is it a problem with the machine?

White is printed in 100% mode and
black is printed in 50% mode.
The same file was used for the output.

IMG_1584
IMG_15841920×3413 304 KB

IMG_1585
IMG_15851920×3413 451 KB

12

Ok, which filament do you use? You used Generic PLA profile and standard print profile to slice (as I can see in 3mf) and it seems that printer/filament max flow is to fast for this filament.

I would choose ‘high quality’ print settings in slicer and create filament profile for the filaments you use because the filament print setting are not OK for both filaments as I see from picture.

You may use this thread to see how you can get better settings for you filament.

p.s.: I would use as infill adaptive cubic, it prints faster at higher strength than cubic!

1 Like