[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