Bed levelling using Z-motors

AlexLin

Hi
I have now 2 independend z motors . Can I do a G29 after the bed levelling with the motors? like this in my bed.g
M561
G29 S2
G28 ; home
G30 P0 X40 Y155 Z-99999 ; probe near a leadscrew
G30 P1 X280 Y155 Z-99999 S2 ; probe near a leadscrew
M557 X40:300 Y15:300 S120
G29

do I need M561 and G29 S2?
when I do this, the height plot indicates that the first lead screw is too high….what I also find surprisin is that the first point, which is near my homing point also is probe as too high? Shouldn't the first point/homing point always be 0?

AlexLin

Ok after adjusting the bed screws it looks better
But still can I combine g30 for motor leveling with g29?

dc42

M561 and G29 S2 do the same thing, they clear bed compensation.

Using G29 after doing true bed levelling is OK. However, you may need to run the bed levelling two or more times to get it accurate, before you run G29.

AlexLin

Thanks… It looks to me when doing several g29 after each other without m561, something accumulated since the first point(home pos) was already too high