jeff.p5 wrote:I am using your solution and it has been very helpful!
I discovered something interesting last night that was repeatable over several tests. I followed your instructions and got to a very nice print that was 0.20 microns. I then decided to do one printout using the same Z adjust value for the whole print. What I found is pictured below. Basically, the bottom right diagonal prints out well, but when the top left diagonal is printed it tears apart at each strand. I tried up to + 50 microns with the results basically staying the same, lower right diagonal (where the print begins is good, top left breaks apart. I redid the XYZ calibration and the result was still the same. I also cleaned the bed with ISO before each print. My Z height is currently at -200
This lends me to believe that my bed is not level, but before changing too many variables I thought I would share my picture and get thoughts of others.
hmmm... normally the meshbed levelling (during the 9 point z-axis calibration) should cope small imperfections in the flatness of the print surface, at least that's what it's supposed to do. but i don't know the range it could do so.
furthermore meshbed leveling assumes that the pinda probe is always able to detect the height between its tip and the copper pads inside the multi-layer heatbed with the same precision at each of the 9 pads. unfortunately reality doesn't follow that approach, because you have other metal parts nearby or under the printbed (for example a bearing under calibration point #4, screws, the frame and the (right) z-axis stepper motor(s)). and in addition, the whole printer operates in an electromagnetic environment where the environmental conditions might severely differ from location to location.
i think that is the reason why there is still the possibility to apply 4 additional correction values (but why only 4 ? nine would be more helpful).
and, last but not least, the pinda's sensitivity is a function of temperature....
don't misunderstand me: i like the meshbed leveling a lot and i think it's one of the key features that contributed to the success of the mk2. but it has it's limits.
so it's always a good idea to get the printbed as flat as you can get it with assembly measures (avoid squeezing when tightening the screws that hold the printbed at the y-carriage, if nescessary use some washers to compensate dips in the surface etc.).
dem inscheniör is' nix zu schwör...