[Solved] Homing question (M561)

[Lakko]

Hi,
i've got a coreXY printer with precision piezo on the hotend.
Searching on the wiki i've found in the Configuring Cartesian printer topic in the "Bed probing file" section this example:

M561 ; clear any existing bed transform
M401 ; deploy Z probe if necessary
G30 P0 X10 Y10 Z-99999 ; define 4 points in a clockwise direction around the bed, starting near (0,0)
G30 P1 X10 Y190 Z-99999
G30 P2 X190 Y190 Z-99999
G30 P3 X190 Y10 Z-99999
G30 P4 X100 Y100 Z-99999 S0 ; finally probe bed centre, and calculate compensation
M402 ; retract the Z probe
G1 X0 Y0 F5000 ; move the head to the corner (optional)

is the M561 needed also at the beginning of the homing sequence?

Thank in advance

[dc42]

You don't have to clear bed compensation before homing. In some older firmware versions it was advised, because Z-homing using a Z probe when bed compensation was being applied could create a Z offset.

OTOH if after homing Z you immediately load a height map file using G29 S1, then I suggest you do clear the height map before Z homing. You can use either M561 or G29 S2 to clear the height map, they do the same thing.

[Lakko]

ok thank you for the explanation