BLtouch on powder coated sheet



  • I just purchased a powder coated sheet to join my collection of build surfaces.
    But now the problem comes, when doing a mesh compensation (G29) I get the wildest landscape, I mean both + and - .2mm, and those values scattered throughout the surface.

    So the small pin of the BLtouch is not suitable for the textured surface..

    The solution that I have in mind is to place a smooth steel sheet and run G32 and G29, and then place the powder coated and only do normal homing. But I would need to home Z in several locations and take the average of those readings.

    Anyone idea how to do this Gcode, or other ideas how to handle BLtouch with powercoated sheets? Another idea I have in mind is to make a little 'foot' for the BLtouch pin, a mechanical solution..

    Any suggestions are most welcome.



  • @bmarkus108 I have bl touch and no issues on powder coated sheet. Do You use genuine one? Which version. I belive pin heat is bigger that the PEI grains on the sheet, but perhaps this is just on my setup.



  • @BoA Yes, genuine BLtouch, and powder coated sheet from PrimaCreator. I know there are differences in grain size among powder coated sheets, this has fairly large grains, significantly larger than the grain on my prusa powder coated sheet.

    I'll try the BLtouch foot idea and will report back.



  • Interesting about the grain size, looking at the two i have it's a world of difference. I think I'd rather probe the bare bed than a stack of sheets, you'll have to set a offset in either case?



  • thats why prusa is using a probe, gives better results on the stell.



  • ![alt text](Prusa powder coated sheet vs PrimaCreator powder coated sheet https://imgur.com/gallery/2YaZtV4)

    Here a little close up of the sheets, I can easily imagine the variations in mesh leveling now, the BL touch pin is about 1mm in diameter at the tip.



  • Have completed some tests with a little foot.
    Results are promising. I don't have screen shot anymore from first mesh leveling, that one had much more dramatic variations. If first try had these results I probably would not have bothered.

    My aluminium plate has quite a curve, will fix that soon by replacing with a thick mirror, upon which I'll sick magnetic sticker.

    See gallery for results:
    alt text



  • @bmarkus108 said in BLtouch on powder coated sheet:

    My aluminium plate has quite a curve, will fix that soon by replacing with a thick mirror, upon which I'll sick magnetic sticker.

    That's going to be a lot of semi insulating material for the heat from the bed to get through. May mean it either takes a long time to get to an operating temperature or possibly the surface will never actually reaches the target.


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