BL touch issue

[yuta4]

Hi, I have an issue with build mesh functionality. After changing the nozzle and readjusting z offset it started produce weird result - all points have negative offset, including central point:


If my knowledge is correct - at least one point (I guess central, home point) should be treated as 0 and all other will have some offset comparing to it, and we should never have the result like I do.
After some random time of restarts I finally get correct result (without other physical or software adjustments from my side, just pressing "auto build mesh" multiple times, including after restart printer, which usually doesn't help)

M48 probe gives fine results for my BL touch, so it is unlikely that issue is related to it

[mriscoc]

It seems to be a mechanical problem, the point of the mesh more close to the center should be close to 0 (green), use a TJC printer firmware to be able to see the numerical values of the mesh: https://github.com/mriscoc/Special_Configurations/releases/tag/tjc

[yuta4]

@mriscoc by mechanical problem you mean problem with CR touch?
Thanks for firmware suggestion, now I have numbers too :)