Kobra Go ABL not working?

[cobalt sapphire]

Been having trouble with this since I bought it. Second hand, previous owner managed anazing articulated and functional prints in both pla and petg no problem.

First layer is never consistent, only thing it's managed to successfully print was the abl height guage. Gcode from teaching tech calibration site, 0.2 layer on 0.4 nozzle, temps 200/60, z offset set to 1mm = to high on the left, perfect in the centre, too low on the right. This is with the "M420 S1" command added from the generator.

Spacers have been replaced as two were ~1-2mm shorter than the others. No manual bed wheels, everything is stock.

[raw tartan]

AI Help

Inconsistent first layers can be caused by a number of factors, including an uneven bed, incorrect bed leveling, or improper nozzle height. Here are a few steps you can try to improve your first layer consistency:

1. Manually level your bed. You can use a sheet of paper or feeler gauge to ensure that the nozzle is the correct distance from the bed at each corner and in the middle.
2. Check the bed itself for any warping or damage that could be causing an uneven surface.
3. Clean your bed surface with rubbing alcohol to ensure there is no residue that could interfere with adhesion.
4. Try adjusting your nozzle height slightly to see if that improves the consistency. You may need to adjust it by fractions of a millimeter until you find the sweet spot.
5. You can also try adjusting your print speed, temperature, or flow rate to help with adhesion.

If you're still having trouble, it may be helpful to share photos of your print and settings, so we can give more specific advice.

WARNING: This response is AI generated and may contain errors.

[wise rose]

As always with hobby 3D printers issues are often a combination of things. Clearly the bed isnt even / flat which is very common. ABL, in theory, should compensate, however as we know the probe mechanically cant reach the whole bed.

A couple of suggestions >
1/ M420 S1 uses a previously stored mesh I much prefer G29 before each print to be sure the the mesh data is accurate.
2/ Getting the bed mechanically level is critical to "help" ABL Yours looks OK and should be fine when ABL is working properly
3/ Print first layer slowly =< 20mm/s
4/ Use and odd number mesh grid so middle point is the same as Z home point
5/ Double probe each point for accuracy
6/ If Bilinear ABL is used make sure you have "EXTRAPOLATE_BEYOND_GRID" enabled so ABL predicts area not reachable by probe
7/ Fine tune first layer in slicer with speed/flow settings

[raw tartan]

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[cobalt sapphire]

1. I got the same result running it with G29 instead
2. Not sure how to change this on pre-gen code, but in my slicer it has first layer set already to 20mm/s as standard
3. Not sure what this is referencing? I don't alter gcodes nor do I have Klipper
4. How do I know which to adjust first?

[wise rose]

1/ OK but G29 generates a new mesh and so if you have a removable bed this is a good thing.

6. I didnt suggest you had klipper . Extrapolate beyond grid is available in Bilinear ABL and can help predict and accommodate the areas the probe cant reach

7/ As you noted your first layer speed is already low. so that's a good thing. If the fill lines of the first layer have gaps increasing the flow can help close them. Like the gaps in your bottom left pic

The rest look pretty good so maybe trying shimming bottom left . A hack is to use kitchen foil in that area to see if improvements can be made