Imperfect Layer Stacking - Print Quality Issue

[3Dexpert]

Hi,


I have this issue which has been occupying me for quite some time now. A picture is attached. As can be seen the layers are not perfectly aligned. I had to make sure the light was falling straight vertically to make this pronounced and visible, otherwise it looks like a normal print. The particular printer this part has come off was Neptune 4 Pro. The following was what I tried in my troubleshooting:


1. Check the extruder for slippage or missing steps.
2. Check all 3 axes for missing steps.
3. Checked belts tension.
4. Turned off StealthChop in klipper (which could introduce small positional errors).
5. Turned off Interpolate function in klipper (which could introduce small positional errors).
6. Decreased microstepping from 128 to 16.
7. Physically tested axes accuracy with a dial test indicator (picture attached).
8. Changed nozzles.
9. Lowered the printing speed.
10. Calibrated the steps of the extruder.
11. Calibrated flow rate.
12. Turned off LA
13. Played with temperatures.
14. Tried different filaments and measured them for consistency.


Hopefully didn't forget anything above.


I could have imagined that this was normal surface quality for an FDM 3D printer. However, I have 3 printers: one is a bulky self built one, one is a Guider2 retrofitted to Klipper and one is Neptune 4 Pro. And the self built one produces almost flawless parts with near perfect layer stacking, while the other 2 have produce this imperfect layer stacking. Incidentally both of which are on Klipper. Unless I have had the self built printer, producing perfect parts, I wouldn't have known this was possible.


Anyway, I would appreciate any input - thoughts/suggestions to try and find a solution to this. It is pretty frustrating. On the Guider2 retrofit, by the way, I have tried swapping 3 different extruders with no lack and swapping the Z screw.


Thanks!