@Phaedrux thank you. This should be very helpful.

@Phaedrux

/31/2020, 7:27:23 PM M115
FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 3.0 ELECTRONICS: Duet WiFi 1.02 or later FIRMWARE_DATE: 2020-01-03b3

NPN inductive Z probe

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Thu May 07 2020 15:49:06 GMT-0400 (Eastern Daylight Time)

; homex.g
; called to home the X axis
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Thu May 07 2020 15:49:06 GMT-0400 (Eastern Daylight Time)
G91 ; relative positioning
; G1 H2 Z20 F120 ; lift Z relative to current position
M92 X172.00 ; set movement speed to match m915 H param
M201 X100.00 ; reduce acceleration
M566 X100.00 ; reduce maximum instantaneous speed changes (mm/min)
G1 H1 X-1160 F6000 ; move quickly to X axis endstop and stop there (first pass)
; G1 H2 Z-5 F6000 ; lower Z again
G90 ; absolute positioning
M92 X80.00 ; set steps per mm back to default
M566 X900.00 ; set maximum instantaneous speed changes back to normal (mm/min)
M201 X500.00 ; set ac

; homey
G91 ; relative positioning
; G1 H2 Z5 F6000 ; lift Z relative to current position
M92 Y172.00 ; set movement speed to match m915 H param
M201 Y100.00 ; reduce acceleration
M566 Y100.00 ; reduce maximum instantaneous speed changes (mm/min)
G1 H1 Y-1430 F6000 ; move quickly to Y axis endstop and stop there (first pass)
;G1 H2 Z-5:-5 F6000 ; lower Z again
G90 ; absolute positioning
M92 Y80.00 ; set steps per mm back to default
M566 Y900.00 ; set maximum instantaneous speed changes back to normal (mm/min)
M201 Y500.00 ; set accelerations back to normal (mm/s^2)

G91 ; relative positioning
G90 ; absolute positioning
; G1 X5 Y-10 F6000 ; go to first probe point
G30 ; home Z by probing the bed

; Uncomment the following lines to lift Z after probing
;G91 ; relative positioning
;G1 Z5 F120 ; lift Z relative to current position
;G90 ; absolute positioning

The last question, I don't have an answer to. I used my Prusa Slicer but I didn't see a setting for a start code. I suspect it my ignorance of the software is at least one of my issues. Thank you for any help you can give. I am new to DIY printers.

Thank you. I will give that a try.

Hi all

Below is my present config file. After I zero my nozzle and attempt to print, the nozzle will not go low enough to give me a good first layer. It seems to start printing at about 2.2 mm above the bed.
Please help!
I am soooo close

; Configuration file for Duet WiFi (firmware version 2.03)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v2.1.8 on Thu May 07 2020 15:49:06 GMT-0400 (Eastern Daylight Time)

; General preferences
G90 ; send absolute coordinates...
M83 ; ...but relative extruder moves
M550 P"My Printer" ; 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 P2 S0 ; physical drive 2 goes backwards
M569 P1 S0 ; physical drive 1 goes backwards
M569 P0 S1 ; physical drive 0 goes forwards
M569 P4 S1 ; physical drive 4 goes forwards
M569 P3 S1 ; physical drive 3 goes forwards
M584 X2 Y1 Z0:4 E3 ; set drive mapping
M350 X16 Y16 Z16:16 E16 I1 ; configure microstepping with interpolation
M92 X80.00 Y80.00 Z1800.00 E420.00 ; set steps per mm
M566 X900.00 Y900.00 Z0.2 E120.00 ; set maximum instantaneous speed changes (mm/min)
M203 X6000.00 Y6000.00 Z120.00 E1200.00 ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z20.00 E250.00 ; set accelerations (mm/s^2)
M906 X1200 Y1400 Z2400 E800 I30 ; set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout

; Axis Limits
M208 X0 Y0 Z0 S1 ; set axis minima
M208 X1160 Y1430 Z1815 S0 ; set axis maxima

; Endstops
M574 X1 S3 ; set endstops controlled by motor stall detection
M574 Y1 S3 ; set endstops controlled by motor stall detection
M574 Z0 P"nil" ; set endstops controlled by probe

; Z-Probe
M558 P5 C"!zprobe.in" H6 F120 T500 ; set Z probe type to switch and the dive height + speeds
G31 P500 X-30 Y-36 Z0.66 ; set Z probe trigger value, offset and trigger height
M557 X0:1160 Y0:1430 S200 ; define mesh grid

; Heaters
M140 H0 ; enable heated bed; map heated bed to heater 0
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
M307 H0 B0 S1.00 ; disable bang-bang mode for the bed heater and set PWM limit

M143 H0 S120 ; set temperature limit for heater 0 to 120C
; M305 P1 T100000 B4138 R4700 ; set thermistor + ADC parameters for heater 1
M308 S0 P"bed_temp" Y"thermistor" T100000 B3950
M308 S1 P"e0_temp" Y"thermistor" T100000 B4138
; M950 H0 C"bed_heat" T0
M950 H1 C"e0_heat" T1
M143 H1 S280 ; set temperature limit for heater 1 to 280C

; Fans
M950 F0 C"!Fan0"
M106 P0 S0.5 H1 T45 ; set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Tools
M563 P0 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

; Custom settings

; X axis sensorless endstop config
M915 X S5 F0 H172 R0

; Y axis sensorless endstop config
M915 Y S8 F0 H172 R0

M501

Great suggestions! I will rewire the x's separately and watch the clones cooling. The z screws are finely threaded rod so falling should be easy to prevent.

Thank you for the information. My big printer is enclosed, all aluminum construction, has a large 1200 mm x 1500 mm stationary heated (eventually) bed of 9 mm aluminum. The x and Y axis are on a gantry that moves up and down on the z axis. Y has one stepper. X has two and z has two large steppers. X's and Y run on linear rails belt driven. The two Z's are on linear rails screw driven. I have a Duet2 wifi v1.03 clone controller with a 7" touch screen. No expansion boards. I do have a separate Dm860AC microstepper driver. All is powered by a 24 volt ac/dc power source. I don't know what I don't know so if you have any suggestions or concerns please let me know.

My question is about the two x and the two z steppers. Can/should I power/control them through the Duet2 or should I control through the Duet and power through the separate micro stepper driver? The larger Z steppers draw 2.8 A each I think.

Thanks again,

@Phaedrux Just saw your custom D-bot. Amazing! Similar to mine. I hope you don't mind me picking your mind. My electrical engineering friend and electrical tech teacher have been of little help.

In reprap config tool it has selection buttons labelled " no z probe, switch, Unmodulated, modulated..etc" it was wondering which an NPN was. Thanks for your help. I am building a fixed bed 1200 x 1500 x 2000 mm Corexy printer with only 3 years of Prusa Mk3s MMU2s experience. It is going to be fun

Hi all. Just starting this process so I apologize in advance for what are likely a long list of stupid questions. What type of z probe is an NPN probe in the reprap config setup?