I have a bltouch clone which work fine on glass bed. After switching to textured PEI sheet, it’s variance trippled to 0.1mm, which make my bed mesh all wobbly.
I’m I suppose to remove the steel plate when making the bed mesh? Do you home Z with a probe with this setup?
The weirdest thing is, despite all this all my prints adhere completely fine. I guess PEI is just that good.
Does the variance return to normal if you switch back to the glass plate? If you probe multiple times on the same spot, do you still get large variance?
Yes to both.
If you press down on the PEI/steel sheet manually, does it look like it’s flexing or does it feel stable? When you switched from glass to steel+PEI, did you put an adhesive magnet sheet on the print carriage, or are you using some other method to hold the print surface in place? Just found a post on reddit where someone discovered that their build plate only sticks to the magnetic sheet when they rotate the plate 90 degrees, so perhaps that’s worth a try.