I have a BLtouch and read alot of guide about how to set up mesh bed compensation, but i feel i don t understand how it behave.
First this is exactly what i do with my duet2:
I set Probe triger height to 0 and reboot.
Next i center and lower my hotend to the point of just touching the bed.
I do a G92 Z0 and a G1 Z10
I then move my probe to the exact same center point and do a G30 S1, 3-4 times and calculate the average (is there a way to automate that?) I enter the value in the config file as my Ztrigerheigth and reboot.
Finally i home all, then move probe to middle at Z10 do a G30 and G29 to get heightmap saved.
Here s a few question:
-The generate heightmap show - and + value of what? The trigerheight or the G30 value or something else.
-If i edit the heightmap manually +value means the nozzle will get closer to the bed and -value nozzle get further away. Or the opposite ?
-Does compensation round up or down number? ie for a value of 0,013 does it translate to +0.01 move or a +0.02 move to the stepper motor? How precise can it be?
-My bed is X220 Y220 but i can only probe from X30X175 and Y20Y200, what happen to the area with no data. Does it keep the last compensate point height or does it go back to a non compensate height (in my case G30 height)?
-Last question. Can G28 probe each point multiple time and take the average. I don t probe before every print i would prefer to do a long and accurate probing session and use the heighmap saved rather than do it every print and get a occasional bad reading from the Bltounch.