This post made me revisit bed levelling, since as I wrote I suffer from a bumpy bed and have the effects of uneven first layer (which I yet ignored since they did not bother me too much). So I followed these guidelines to run a “manual” 11x11 grid calibration. I ran it twice to see how stable data is, and I was positively impressed how consistent the measurements are (see images below - when I flip between the two graphs, they are nearly identical but for a slight Z offset). After that, I did the touchscreen 5x5 grid and I can immediatly see that it is too coarse to take care of my bumps. And I guess that’s what I see in my first layers. Plan for the future:
a) do the next print with an 11x11 calibration (@gwfami perhaps you should try this too)
b) get washers to put between carrier grid and heated bed to smooth out bumpiness
And here are the results of above calibration runs:
