Feature request: Mesh bed correction

Features
1

Hi, I’ve been having mesh leveling issue on producing the perfect the first layer. Most likely due to the twisted axis. Is there any chance that Klipper can bring the mesh bed correction (print 3x3 squares across the bed and adjust the manual correction amount for four sides) feature from Marlin? That’d be very useful for any printers that have small mechanical imperfections to get a better first layer.

Thank you!
CJ

2

Hello @valjiach !

If you have independent Z-axes, you already have it:

https://www.klipper3d.org/Config_Reference.html?h=pixel#z_tilt

https://www.klipper3d.org/Config_Reference.html?h=pixel#quad_gantry_level

3

Not sure that’s the same as mesh correction (bed level correction)…my prusa mk2.5 has that and it doesn’t seem to have independent z drivers. In the correction, it offers front, back, left and right bed level correction.

4

I see, you seek an aid to turn the screws below the bed into the proper position?

https://www.klipper3d.org/Config_Reference.html?h=pixel#bed_screws

https://www.klipper3d.org/Config_Reference.html?h=pixel#screws_tilt_adjust

5

Thanks for quick replying. Not that either I think. Mk2.5 doesn’t have bed screws. It may be adding or subtracting z value on top of the final mesh.
See the link below
https://help.prusa3d.com/article/bed-level-correction_2267

6

I think this is about applying different offset values to the mesh data, to correct for constant inaccurate measurements by the probe.
For example: People using Klicky probes on cantilevered beds, like me on a V0, have the problem that the bed flexes differently under the probes pressure from back to front. So the probe always measures a seemingly to low bed position in the front, and over corrects it. This always leads to a too low first Layer in the front of the bed and/or too high layer in the back. In my case it’s a perfect gradient of 0.2mm front to back.

This could be solved by applying a hand written offset-mesh to the mesh profile. I think all it needs to implement this would be a way to mathematically add two mesh profiles together.