Set Z-axis manually Because I experience many problems getting the hight right because of instability of the IR sensor (I'm reading those topics with great interest) I decided to set the Z-axis manually for the time being, just to get printing. However It does not work as I expect. The procedure I followed: - M561 (Reset Bed Compensation) - M556 S100 X0 Y0 Z0 (Reset XYZ asis compensation) - HOME - G32 (seems to work fine) - Raise head by 5 mm - G1 X100 Y100 - Manually adjust height "paper thick" above the bed - G92 Z0 Now when I start printing, it prints "in the air" When I repeat the above procedure and directly after G92 Z0 I ask the machine the position (M114) it says: "X=100 Y=100 Z=-0.312586 E=0.0000 Why? I just told the machine it was at Z=0 and it did not move since ... It appears that the bed compensation creates the Z=-0.312586 at pos X100 Y100, because if I omit the G32 in the above procedure it works as expected. Where am I thinking wrong? Kind regards, Leon https://reprap.org/forum/read.php?340,307652,307652#msg-307652 Sat, 13 Jun 2026 14:11:15 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?340,307652,307843#msg-307843 Re: Set Z-axis manually https://reprap.org/forum/read.php?340,307652,307843#msg-307843 rm2014 Ormerod Fri, 07 Feb 2014 19:20:08 -0500 https://reprap.org/forum/read.php?340,307652,307841#msg-307841 Re: Set Z-axis manually https://reprap.org/forum/read.php?340,307652,307841#msg-307841
The G92 now works as I would expect.

Thanks a lot!]]> lvperlo Ormerod Fri, 07 Feb 2014 19:13:42 -0500 https://reprap.org/forum/read.php?340,307652,307836#msg-307836 Re: Set Z-axis manually https://reprap.org/forum/read.php?340,307652,307836#msg-307836 dc42 Ormerod Fri, 07 Feb 2014 19:09:29 -0500 https://reprap.org/forum/read.php?340,307652,307833#msg-307833 Re: Set Z-axis manually https://reprap.org/forum/read.php?340,307652,307833#msg-307833 rm2014 Ormerod Fri, 07 Feb 2014 19:00:52 -0500 https://reprap.org/forum/read.php?340,307652,307828#msg-307828 Re: Set Z-axis manually https://reprap.org/forum/read.php?340,307652,307828#msg-307828
Quote
lvperlo
Why? I just told the machine it was at Z=0 and it did not move since ...

It appears that the bed compensation creates the Z=-0.312586 at pos X100 Y100, because if I omit the G32 in the above procedure it works as expected.

I've just fixed this in my latest firmware. When you run G92 Z0 it really does set Z=0 now. See [forums.reprap.org].]]> dc42 Ormerod Fri, 07 Feb 2014 18:23:55 -0500 https://reprap.org/forum/read.php?340,307652,307674#msg-307674 Re: Set Z-axis manually https://reprap.org/forum/read.php?340,307652,307674#msg-307674
I find the following script very useful, i have replaced my homez.g file (in the sys directory) with it and helps alot with homing Z. After running this the head will be a the first bed compensation point X and Y, and the sensor decided Z, I then move Z down to paper thickness and re-run another G92 Z0.

by the way your problem may be caused by the fact that you can only run G92 Z0 at the first bed compensation point and not at any other location.

Matt

p.s. change my bed comp measurements for yours before using =)

; RepRapPro Ormerod
; Home Z
M561 ; Remove bed compensation
M120 ; Push feedrate & absolute/relative positioning
G91 ; Set relative movement
G1 Z5 F200 ; Move up 5mm
G90 ; set absolute movement
G1 X55 Y0 ; Move to IR reading point
G30 ; Use IR probe to set height
G30 P0 X60 Y20 Z0.0
G30 P1 X60 Y170 Z-0.25
G30 P2 X170 Y170 Z-0.2
G30 P3 X170 Y20 Z0.20 S
G1 X60 Y20 ; Move to the zero compensation position
G1 Z0 F200 ; Move to Z zero position
M121 ; Pop feedrate and absolute/relative positioning]]> iamburny Ormerod Fri, 07 Feb 2014 12:16:24 -0500 https://reprap.org/forum/read.php?340,307652,307662#msg-307662 Re: Set Z-axis manually https://reprap.org/forum/read.php?340,307652,307662#msg-307662 dc42 Ormerod Fri, 07 Feb 2014 11:57:11 -0500 https://reprap.org/forum/read.php?340,307652,307652#msg-307652 Set Z-axis manually https://reprap.org/forum/read.php?340,307652,307652#msg-307652
The procedure I followed:
- M561 (Reset Bed Compensation)
- M556 S100 X0 Y0 Z0 (Reset XYZ asis compensation)
- HOME
- G32 (seems to work fine)
- Raise head by 5 mm
- G1 X100 Y100
- Manually adjust height "paper thick" above the bed
- G92 Z0

Now when I start printing, it prints "in the air"

When I repeat the above procedure and directly after G92 Z0 I ask the machine the position (M114) it says:
"X=100 Y=100 Z=-0.312586 E=0.0000

Why? I just told the machine it was at Z=0 and it did not move since ...

It appears that the bed compensation creates the Z=-0.312586 at pos X100 Y100, because if I omit the G32 in the above procedure it works as expected.

Where am I thinking wrong?

Kind regards,
Leon]]> lvperlo Ormerod Fri, 07 Feb 2014 11:41:47 -0500