Z height always not respected

[BoA]

This is messed up...

1. No G28 in start code, so no proper homing
2. M98 P"homeall.g" should not be in bed.g

For start code basic sequence should be something like:
G28 ; home all without mesh bed level
G32 ; gantry leveling
G29 ; mesh bed compensation

that's for start.

Also. If You just execute G28, is the nozzle on the right height - Z trigger height is correct? And by "nozzle is too high" - by how much?

[Ducati87]

@BoA said in Z height always not respected:

This is messed up...

1. No G28 in start code, so no proper homing
2. M98 P"homeall.g" should not be in bed.g

For start code basic sequence should be something like:
G28 ; home all without mesh bed level
G32 ; gantry leveling
G29 ; mesh bed compensation

that's for start.

Also. If You just execute G28, is the nozzle on the right height - Z trigger height is correct? And by "nozzle is too high" - by how much?

I call only G32 in the start gcode because I have the G28 and G29 S1 in the bed.g

[BoA]

@Ducati87 Well... I do not see any G28

I know what You have in bed.g
What I wrote is that You should not have it there

[Ducati87]

@BoA said in Z height always not respected:

@Ducati87 Well... I do not see any G28

I know what You have in bed.g
What I wrote is that You should not have it there

ok I will try as you suggested.

[Ducati87]

@BoA said in Z height always not respected:

This is messed up...

1. No G28 in start code, so no proper homing
2. M98 P"homeall.g" should not be in bed.g

For start code basic sequence should be something like:
G28 ; home all without mesh bed level
G32 ; gantry leveling
G29 ; mesh bed compensation

that's for start.

Also. If You just execute G28, is the nozzle on the right height - Z trigger height is correct? And by "nozzle is too high" - by how much?

When I call G28 the value is about 6.00. If I use the babystep I have to go over the 1.4mm....

[BoA]

@Ducati87 Ok then, so assuming this is bltouch

M558 P9 C"^zprobe.in" H3 F420 T9000

F420 - too fast for bltouch, I would use F120
If nozzle if 1.4mm too high - I would adjust Z trigger height

G31 P500 X22 Y-37 Z4.470 ; 3.070 + 1.4

[Ducati87]

@BoA said in Z height always not respected:

@Ducati87 Ok then, so assuming this is bltouch

M558 P9 C"^zprobe.in" H3 F420 T9000

F420 - too fast for bltouch, I would use F120
If nozzle if 1.4mm too high - I would adjust Z trigger height

G31 P500 X22 Y-37 Z4.470 ; 3.070 + 1.4

for too high I mean too FAR.

[BoA]

@Ducati87 said in Z height always not respected:

for too high I mean too FAR.

That is what I assumed

[Ducati87]

@BoA said in Z height always not respected:

@Ducati87 said in Z height always not respected:

for too high I mean too FAR.

That is what I assumed

ok I said just to clarify.

[BoA]

@Ducati87 Just one question - is that a new setup, or it was working, and is not working correctly now?

[Ducati87]

@BoA said in Z height always not respected:

@Ducati87 Just one question - is that a new setup, or it was working, and is not working correctly now?

it worked until I had to redo the procedure following the hotend change.

[BoA]

@Ducati87 And let me guess... new hotend is about 1.4mm shorter/higher or... bltouch 1.4mm lower

You can get more precise results by setting:

G31 P500 X22 Y-37 Z0.0

homing using G28

going to Z0.0 (indicated) and measuring actual nozzle tip height. Then put this measurement value as Z trigger height in G31

or after homing disable limits by M564 S0
and move head down just to touch the bed by nozzle tip, and use indicated Z value a trigger height (remove the minus obviously)

[Ducati87]

@BoA said in Z height always not respected:

@Ducati87 And let me guess... new hotend is about 1.4mm shorter/higher or... bltouch 1.4mm lower

You can get more precise results by setting:

G31 P500 X22 Y-37 Z0.0

homing using G28

going to Z0.0 (indicated) and measuring actual nozzle tip height. Then put this measurement value as Z trigger height in G31

or after homing disable limits by M564 S0
and move head down just to touch the bed by nozzle tip, and use indicated Z value a trigger height (remove the minus obviously)

I did it a couple of times but with same results. the value detected by the procedure is not accurate.

[BoA]

@Ducati87 Well... that mostly depends on probe and Your measurements accuracy. Did You slow down probing speed to 120 ?

[Ducati87]

@BoA said in Z height always not respected:

@Ducati87 Well... that mostly depends on probe and Your measurements accuracy.

it's an original BLtouch 3.1...I cannot understand where the problem is.

[BoA]

@Ducati87 You can try to add A parameter to M558, for example A4. And slow down probing speed to 120

[Ducati87]

@BoA said in Z height always not respected:

@Ducati87 You can try to add A parameter to M558, for example A4. And slow down probing speed to 120

ok I will try. Thank you BoA!

[Phaedrux]

After you changed the hotend did you remeasure your trigger height?

https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe

[Ducati87]

@Phaedrux said in Z height always not respected:

After you changed the hotend did you remeasure your trigger height?

https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe

Yes of course but every time I have to adjust the height with babystep.

[Phaedrux]

Could you share your current config.g, homeall/homez, bed.g, and your slicer start gcode all together in a single post? That way I can see what's going on more clearly.

If the amount of baby stepping required is consistent, you can modify the G31 and it should take effect. If it's not taking effect than something in the gcode order is not right.