Hi
This is driving me nuts and I've probably missed something stupid.
I've taken an Anycubic i3 Mega, gutted it and swapped the electronics for a Duet Wifi I had spare. Z and X axis homing is done by a Mini Differential IR board.
Everything appears to be working fine but whenever I run Homeall the nozzle lifts to 7.5mm above the bed at the end of the script. Trigger height is 2.5mm so something somewhere is causing the z axis to raise 5mm. I can't see what it is so if somebody can point out what I've missed it would be appreciated.
Config.g
; Configuration file for Duet WiFi (firmware version 3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Wed Apr 08 2020 14:00:34 GMT+0100 (British Summer Time)
; General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"i3 MEGA" ; set printer name
; Network
M552 S1 ; enable network
M586 P0 S1 ; enable HTTP
M586 P1 S0 ; disable FTP
M586 P2 S0 ; disable Telnet
; Drives
M569 P0 S1 ; physical drive 0 goes forwards X
M569 P1 S0 ; physical drive 1 goes backwards Y
M569 P2 S0 ; physical drive 2 goes backwards Z
M569 P3 S1 ; physical drive 3 goes forwards E0
M569 P4 S1 ; physical drive 4 goes forwards E1
M584 X0 Y1 Z2 E3:4 ; set drive mapping
M350 X16 Y16 Z16 E16:16 I1 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z400.00 E413.79:420.00 ; set steps per mm
M566 X900.00 Y900.00 Z12.00 E120.00:120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z180.00 E1200.00:1200.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 E250.00:250.00 ; set accelerations (mm/s^2)
M906 X800 Y800 Z800 E800:800 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout
; Axis Limits
M208 X0 Y-25 Z0 S1 ; set axis minima
M208 X225 Y225 Z200 S0 ; set axis maxima
; Endstops
M574 X1 S2 ; configure Z-probe endstop for low end on X
M574 Y1 S1 P"ystop" ; configure active-high endstop for low end on Y via pin ystop
M574 Z1 S2 ; configure Z-probe endstop for low end on Z
; Z-Probe
M558 P1 C"zprobe.in" H5 F120 T6000 ; set Z probe type to unmodulated and the dive height + speeds
;M558 H30 ;*** Remove this line after delta calibration has been done and new delta parameters have been saved
G31 P500 X-20 Y-5 Z2.5 ; set Z probe trigger value, offset and trigger height
M557 X15:215 Y15:215 S20 ; define mesh grid
; Heaters
M308 S0 P"bedtemp" Y"thermistor" T100000 B4138 ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bedheat" T0 ; create bed heater output on bedheat and map it to sensor 0
M143 H0 S120 ; set temperature limit for heater 0 to 120C
M307 H0 B1 S1.00 ; enable bang-bang mode for the bed heater and set PWM limit
M140 H0 ; map heated bed to heater 0
M308 S1 P"e0temp" Y"thermistor" T100000 B4138 ; configure sensor 1 as thermistor on pin e0temp
M950 H1 C"e0heat" T1 ; create nozzle heater output on e0heat and map it to sensor 1
M143 H1 S280 ; set temperature limit for heater 1 to 280C
M307 H1 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
M308 S2 P"e1temp" Y"thermistor" T100000 B4138 ; configure sensor 2 as thermistor on pin e1temp
M950 H2 C"e1heat" T2 ; create nozzle heater output on e1heat and map it to sensor 2
M143 H2 S280 ; set temperature limit for heater 2 to 280C
M307 H2 B0 S1.00 ; disable bang-bang mode for heater and set PWM limit
; Fans
M950 F0 C"fan0" Q500 ; create fan 0 on pin fan0 and set its frequency
M106 P0 S0 H-1 ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"fan1" Q500 ; create fan 1 on pin fan1 and set its frequency
M106 P1 S0 H-1 ; set fan 1 value. Thermostatic control is turned off
; Tools
M563 P0 S"HE 0" D0 H1 F0 ; define tool 0
G10 P0 X0 Y0 Z0 ; set tool 0 axis offsets
G10 P0 R0 S0 ; set initial tool 0 active and standby temperatures to 0C
M563 P1 S"HE 1" D1 H2 F1 ; define tool 1
G10 P1 X0 Y0 Z0 ; set tool 1 axis offsets
G10 P1 R0 S0 ; set initial tool 1 active and standby temperatures to 0C
; Custom settings are not defined
; Miscellaneous
M501 ; load saved parameters from non-volatile memory
M911 S10 R11 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; set voltage thresholds and actions to run on power loss
Homeall.g
; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Wed Apr 08 2020 14:00:34 GMT+0100 (British Summer Time)
G91 ; relative positioning
G1 H2 Z5 F6000 ; lift Z relative to current position
G1 H1 X-230 Y-255 F1800 ; move quickly to X and Y axis endstops and stop there (first pass)
G1 H2 X5 Y5 F6000 ; go back a few mm
G1 H1 X-230 Y-255 F360 ; move slowly to X and Y axis endstops once more (second pass)
G90 ; absolute positioning
G1 X25 Y0 F6000 ; go to first bed probe point and home Z
G30 ; home Z by probing the bed
;G91 ; relative positioning
;G1 Z5 F100 ; lift Z relative to current position
;G90 ; absolute positioning
Thanks in advance
Jon