Conditional homing and z-height fine adjustment

fcwilt

@GuidoP said in Conditional homing and z-height fine adjustment:

Homing is initiated. X and Y homing will initiate (in the default g-code) a Z move in the z-max direction. Regardless if z-max or z-min is used

If it moves in the Z max direction when using Z min end stop then something is wrong. It should not do that.

Frederick

Phaedrux

@fcwilt said in Conditional homing and z-height fine adjustment:

If it moves in the Z max direction when using Z min end stop then something is wrong. It should not do that.

Maybe he means the small lift before homing x and y for clearance?

fcwilt

@Phaedrux said in Conditional homing and z-height fine adjustment:

Maybe he means the small lift before homing x and y for clearance?

What small lift? I must do things backwards. I home Z first and then move to Z=5 before I home Y & X.

Frederick

Phaedrux

@fcwilt For instance in homeall.

G1 Z5 F100 S2 ; Lower bed 5mm to ensure it is below the trigger height

fcwilt

@Phaedrux said in Conditional homing and z-height fine adjustment:

@fcwilt For instance in homeall.

G1 Z5 F100 S2 ; Lower bed 5mm to ensure it is below the trigger height

What would you do that?

Consider when homing to Z min:

G1 Z-999 H1
G1 Z20
G1 Z-999 H1

When the first G1 executes if the endstop is already triggered no movement takes place and the next G1 executes which is safe.

Am I overlooking something?

Frederick

Phaedrux

@fcwilt said in Conditional homing and z-height fine adjustment:

Am I overlooking something?

Yes, when using a probe you must position the probe first, so X and Y must be homed first, and by default the configurator includes a short lift of the Z axis to give clearance for the X Y move and to lift the probe above trigger height.

But I was just speculating on what he might have been meaning.

fcwilt

@Phaedrux said in Conditional homing and z-height fine adjustment:

Yes, when using a probe you must position the probe first, so X and Y must be homed first, and by default the configurator includes a short lift of the Z axis to give clearance for the X Y move and to lift the probe above trigger height.

Ah... I see.

I use a Z min endstop switch setup for homing in relation to the frame so I never encountered that issue.

I only use the Z probe for setting Z=0 and mesh comp probing, things which only occur after the ZYX homing has been done.

Thanks.

Frederick

GuidoP

@Phaedrux said in Conditional homing and z-height fine adjustment:

@fcwilt said in Conditional homing and z-height fine adjustment:

If it moves in the Z max direction when using Z min end stop then something is wrong. It should not do that.

Maybe he means the small lift before homing x and y for clearance?

Thats correct

GuidoP

Thanks all for the input, but unfortunately it does not bring me closer to an answer to the original question: Why does the conditional gcode not work as intended? Where is the bug in the code??

GuidoP

I finally got the macro working with following code:

; Source: https://forum.duet3d.com/topic/4202/homing-to-z-max-when-also-using-a-z-probe/19
; Start g-code: G28, M98 P"0:/macros/Leveling/SetZ" ; run z fine tuning

; If the printer hasn't been homed, home it

;M291 P"checking homing status" R"Homing status" S1			; Report status

if !move.axes[0].homed || !move.axes[1].homed || !move.axes[2].homed  	; Check if axis are not homed
  ;If axis are not homed, home axis
  echo "Axis are not homed, performing homing"
  M98 P"0:/sys/homeall.g"
else
  ;If axis are already homed, home only the X and Y axis
  echo "axis are homed, re-homing x and Y"
  M98 P"0:/sys/homex.g"											; Run the Home X macro
  M98 P"0:/sys/homey.g"											; Run the Home Y macro
  ;G1 X100 Y100 H0 F1800											; move to be centre slowly.
  
;End homeing check
M291 P"Axis homed" R"Homing status" S1							; Report status
;echo "start fine tuning z-level"
G1 X100 Y100 H0 F1000											; move to be centre slowly.
G1 Z15 H1 F8000	 	 											; Raise the bed to start probing
G30 															; probe for z=0
G1 Z10 H1 F1000 												; raise nozzle
G30 S-1 														; check z gap
G1 Z10 H1 F1000 												; raise nozzle

M400															; Wait until all moves are completed

I changed and tested several different thing, but i think the trick that did it was removing the empty line between the end of the "If" block and the start of the "else" block.