Z height strangeness
Fairly new to 3d printing and certainly new to the Duet Wifi.
Have got a problem where I (manually) level my bed as I have no IR probe and when I got to print always starts about 0.2mm below the freshly levelled z0.
I don't understand why I can home everything, level the bed on multiple positions and then when it comes to printing the print starts at a completely different z height.
How can it go lower than z0 as set by my Z end stop (two wire close/open switch)?
And why is it doing it??
I have no z offset in the GCode of my slicer (Simplify 3D)
My end stop set up is as follows:
[[language]] ; Endstops M574 X1 Y1 Z1 S0 ; Set active low endstops M558 P0 H5 F120 T6000 ; Set Z probe type to switch and the dive height + speeds G31 P500 X0 Y0 Z0 ; Set Z probe trigger value, offset and trigger height M557 X25:175 Y25:175 S20 ; Define mesh grid
Note: G31 was set as
G31 P500 X0 Y0 Z2.5
so I changed it to 0 with no difference.
Should I have increased it instead?
Please post the contents of your homez.g and homeall.g files.
[[language]] ; homez.g ; called to home the Z axis ; ; generated by RepRapFirmware Configuration Tool on Mon Mar 05 2018 14:15:11 GMT+0000 (GMT) G91 ; relative positioning G1 Z5 F6000 ; lift Z relative to current position G1 S1 Z-185 F1800 ; move Z down until the switch triggers G92 Z2.5 ; set Z position to trigger height ; Uncomment the following lines to lift Z after probing ;G91 ; relative positioning ;G1 Z5 F100 ; lift Z relative to current position ;G90 ; absolute positioning
And here's homeall.g
[[language]] ; homeall.g ; called to home all axes ; ; generated by RepRapFirmware Configuration Tool on Mon Mar 05 2018 14:15:11 GMT+0000 (GMT) G91 ; relative positioning G1 Z5 F6000 ; lift Z relative to current position G1 S1 X-205 Y-205 F4800 ; move quickly to X and Y axis endstops and stop there (first pass) G1 X5 Y5 F6000 ; go back a few mm G1 S1 X-205 Y-205 F360 ; move slowly to X and Y axis endstops once more (second pass) G1 S1 Z-185 F1800 S1 ; move Z down stopping at the endstop G90 ; absolute positioning G92 Z2.5 ; set new Z position ;G1 Z5 F100 ; uncomment this line to lift the nozzle after homing
I'm guessing the problem is those G92 commands?
Should they be set to 0 then?
If so, I'm curious why the riprap configure tool sets this as default. Especially when it clearly seemed to understand that I had a z end stop switch only and no probe.
Surely it would have been better for it to default to 0 and not wreck peoples beds
OK, so I've altered the home files' G92 commands to Z0 and it has worked well. Phew!
@dc42: thanks for pointing me in the right direction. (great board btw)