G92 behavior affected by M208 ???
-
The release notes for 2.03beta1 include this entry:
Bug fixes
...- G92 should not constrain the passed coordinates to the M208 limits if M564 S0 has been used to disable limits
-
@msjfb said in G92 behavior affected by M208 ???:
Thanks for the replies,
I was looking to duplicate this, trying not to have to modify more than one entry when adjusting the bed. Specifically not having to change code both in HomeAll and HomeZ everytime I make changes to the bed.
My HomeAll file simply calls HomeX, HomeY and HomeZ.
Frederick
-
@msjfb said in G92 behavior affected by M208 ???:
trying not to have to modify more than one entry when adjusting the bed. Specifically not having to change code both in HomeAll and HomeZ everytime I make changes to the bed.
What do you have for a z probe? If you have a contact probe that can accurately set Z0 regardless of the surface, your first layer height in the slicer should be all you need to adjust for different materials, no?
-
I am using a Hall effect switch as Z endstop. No probe as such yet.
The switch is very effective up to now, and trigger position is always within +-0.01mm (measured with a digital dial indicator).
So I measure actual offset to the bed, and plug it in the homing macros.If my 1/4in MIC6 aluminium bed bed turns out to be too uneven, I will add a probe (piezo?) , but preliminary tests show it is flat within 0.1mm. I have yet to test with large prints (300x300 bed).
-
In that case, I would second nhof's suggestion above.
-
That's pretty much what I have done.
For anyone interested in this:Config.g:
; ############## Axis Limits ##############
M208 X-5.5 Y-15.3 Z0 S1 ; Set axis minima S1: XY is current offset from endstop. Z set to 0, offset to be modified in homing macros
M208 X300 Y300 Z300 S0 ; Set axis maxima S0HomeZ.g:
; homez.g
; called to home the Z axis
;Hall effect switch homingM564 S0 H0 ;allow movement of axes that have not been homed (firmware 1.21 and later)
G91 ; relative positioning
M400 ; make sure everything has stopped before we make changes
M913 Z80 ;set motor to 80%
M574 Z1 S0 ; set Z endstop
G1 Z-300 F400 S1 ; move Z carriage towards endstop
G1 Z10 F400 ; move down 10mm
G1 Z-11 F100 S1 ; slowly move Z carriage towards endstop
M400 ; make sure everything has stopped before we make changes
M913 Z100 ;set motor to 100%
G90 ; absolute positioning;###########################################################################################
G92 Z5.0 ; set actual nozzle height above bed !! !ADJUST FOR BED HEIGHT !!!
;###########################################################################################M564 S1 H1 ; restrict axes movement within boundaries
-
@msjfb said in G92 behavior affected by M208 ???:
That's pretty much what I have done.
For anyone interested in this:Config.g:
; ############## Axis Limits ##############
M208 X-5.5 Y-15.3 Z0 S1 ; Set axis minima S1: XY is current offset from endstop. Z set to 0, offset to be modified in homing macros
M208 X300 Y300 Z300 S0 ; Set axis maxima S0HomeZ.g:
; homez.g
; called to home the Z axis
;Hall effect switch homingM564 S0 H0 ;allow movement of axes that have not been homed (firmware 1.21 and later)
G91 ; relative positioning
M400 ; make sure everything has stopped before we make changes
M913 Z80 ;set motor to 80%
M574 Z1 S0 ; set Z endstop
G1 Z-300 F400 S1 ; move Z carriage towards endstop
G1 Z10 F400 ; move down 10mm
G1 Z-11 F100 S1 ; slowly move Z carriage towards endstop
M400 ; make sure everything has stopped before we make changes
M913 Z100 ;set motor to 100%
G90 ; absolute positioning;###########################################################################################
G92 Z5.0 ; set actual nozzle height above bed !! !ADJUST FOR BED HEIGHT !!!
;###########################################################################################M564 S1 H1 ; restrict axes movement within boundaries
Interesting.
A few questions if you don't mind:
- why the M564 commands?
- why is the M574 command not in your config.g file?
- why the M913 commands?
Thanks.
Frederick
-
@fcwilt :
M564: I have found that I cannot move the axes without homing, and to home I need to allow 'free' movement of the axes. Hence M564 S0 R0 at the topM574: It is already in the config file, I just repeat it here for good measure
M913: I use sensorless homing (no endstop switches in X&Y) so I first set motor current to 80% before homing so that the carriage does not 'crash' too hard into the physical endstop, and then reset the motor to 100% . I agree that I normally would not need to do this for Z since I have a switch for this axis. But I prefer to home with less motor torque in all axes just in case...
-
@msjfb said in G92 behavior affected by M208 ???:
@fcwilt :
M564: I have found that I cannot move the axes without homing, and to home I need to allow 'free' movement of the axes. Hence M564 S0 R0 at the topM574: It is already in the config file, I just repeat it here for good measure
M913: I use sensorless homing (no endstop switches in X&Y) so I first set motor current to 80% before homing so that the carriage does not 'crash' too hard into the physical endstop, and then reset the motor to 100% . I agree that I normally would not need to do this for Z since I have a switch for this axis. But I prefer to home with less motor torque in all axes just in case...
Thanks for the feedback.
In regards to the M564: The first G1 command has the S1 parameter which allows movement when not homed. Once the endstop is triggered by that command the axis is considered to be homed and thus all movement commands are allowed. So the M564 does not hurt but is not necessary.
Frederick
-
Since I was very careful when first testing the motion system, I was moving the axes with manual commands (no S1 parameter).
I never suspected that 'moving to sensor' would work off the top.
I am assuming that this means that the M564 command at the end is also redundant since S1 H1 are the defaults ?Thanks for pointing that out. I'll update my files...