BED_MESH_CALIBRATE: algorithm is not set, yet automatically chosen incorrectly

General Discussion
1

Basic Information:

Printer Model: Ender5+
MCU / Printerboard: BTT Octopus
Host / SBC RPi3, fluidd
klippy.log klippy.zip (301.0 KB)

Describe your issue:

Well, in short, I just wanted to run a custom bed mesh with excessively dense coverage for comparing two beds. Since it is implied in the docs that this should be possible with a direct command (without editing printer.cfg, say by running BED_MESH_CALIBRATE PROFILE=default METHOD=automatic MESH_MIN=10,30 MESH_MAX=300,320 PROBE_COUNT=12,12), but that isn’t working, I had to dig deeper.

So I set [bed_mesh] probe count to 12, restarted the thing, and was greeted with

bed_mesh: cannot exceed a probe_count of 6 when using lagrange interpolation. Configured Probe Count: 12, 12

Since I never set the algorithm for meshing, I consider automatically choosing an incompatible algorithm to be a bug.

For quick reference, this is the [bed_mesh] section:

[bed_mesh]
speed: 150
horizontal_move_z: 7.5
mesh_min: 10, 30
mesh_max: 300, 320
probe_count: 12
2

Umm, no. I’d consider it a lack of understanding and a lack of reading the documentation.

grafik
grafik1075×341 47.3 KB

If you use mesh interpolation (which equally is default) then you need an algorithm to do so. For details, refer to Configuration reference - Klipper documentation and Bed Mesh - Klipper documentation

3

Nice try, but I prefer rude answers to actually disprove my point.

image
image1075×142 21.3 KB

Since there IS some code running that forces 3x3 grids to be run in lagrangian mode regardless of the set algorithm, why is it not also forcing bicubic for cases that the default lagrange algorithm cannot handle?

4

I’m really not sure what you are trying to convey:

  1. Klipper is setting sane defaults for 3D printing
  2. The defaults are documented
  3. For this case the advance information is in the bed mesh chapter:
    grafik
    grafik1237×323 24.6 KB
  4. You always have the option to set the values as you would like
  5. If you do not want mesh interpolation and resulting from no interpolation no algorithm, then set mesh_pps: 0. This is equally documented here:
    grafik

Now before trying to be extra smart, please be so kind and read the documentation.

5

Please be so kind and make sure all of your accusations are actually in line with the original post that states:

Furthermore, community guidelines also apply to you (in case you didn’t know/remember).

6

sigh
So, we conclude this discussion with:

  • It is not a bug.
  • It is the documented default behavior.
  • It can be changed within the documented limits, e.g., depending on mesh size.
  • It can be turned off by setting mesh_pps: 0 (equally documented), as then the algorithm plays no role since no interpolation is performed.

Have a nice evening.

3 Likes