The thumbwheel are only for securing and fastening the bed. I've used printed distance bits between the Andromeda and heatbed :

@adam2070 This is how I have made the mounts for the Andromeda on my D-Bot:

@supraguy I'm suspecting interferens on the wires to the piezo elements, where have you mounted the P20 card?

I've mounted four of the andromeda sensors under bed on my D-BOT. using the P20 V1.1 controller plugged in to the Z probe socket on my Duet Wifi motherboard, and gconfig as prescribed. I have to bang the heatbed really hard to get a reaction. Afterwards I did some testing with a lab power supply set at 3.3v, and it worked flawlessly when I tap the bed, the blue led did light up, and it was easy to adjust sensitivity. The wires was at the same length. And the messured v output from the board was the same as from the lab psu. I'm stuck here, anybody any suggestions?

Hi!
I did find where the problem was, I changed the Y and X motors from 1.8 steppers to 0.9 steppers a while ago. It looks like the holding torque of the 0.9 steppers was too low. When I stepped back, and mounted the 1.8 steppers, the printer worked as it always have.

Hi! Thank you for a quick respond to my problem.
I had used M584 to remap the X driver, but now I have it back on the original position. And the warning report list looks way better. At the same time I looked over all the electrical on the main board, to eliminate any problem with the hardware. I don't use the M911 code yet, is this something I should have done?

Sorry for a late respons.
No, I struggling with the same problem, upgrade to the latest firmware and web control. This time I got a longer alarm list, looks like it's a driver problem? I use 0.9 steppers on XY axis, is those a problem? I've tried different prints, also lasting over 4 hours with a good result. so I'm really confused. The whole thing is on 24v. Unless the heated bed, it's on 220v, via SSR relay.
This is what the Duet tells me

My D-BOT with Duet Wifi have got a strange behavior, it release a ![M25 resume-after-power- fail-state saved https://1drv.ms/f/s!AmiXGFnLNvHbsyhH8CDJG-PHfQa4, and start printing in a wrong place, moving diagonally against Y0/Xmax.
I need some input on this, I've tried everything to get this right, but the error is still there. I have tried a new PSU, but it didn't help any. I've used my printer for several months, and have not change the settings and this occur this week. Next I'll try, is to check all motor plug in, but now I search in the dark, any suggestions?

I forgot this:

Firmware Name:
RepRapFirmware for Duet 2 WiFi/Ethernet
Firmware Electronics:
Duet WiFi 1.02 or later + DueX5
Firmware Version:
2.0(RTOS) (2018-06-05b3)
WiFi Server Version:
1.19
Web Interface Version:
1.19

I'm setting up a sensorless homing on my D-BOT, but it seems like I am doing something wrong in my config files.

Here are my present config.g and homing files:

; Configuration file for Duet WiFi (firmware version 1.20 or newer)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool on Mon Mar 26 2018 16:38:56 GMT+0200 (W. Europe Daylight Time)

; General preferences
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves

M667 S1 ; Select CoreXY mode

; Network
M550 PMy printer ; Set machine name
M552 S1 ; Enable network

; Drives
M569 P0 S1 ; Drive 0 goes forwards
M569 P1 S1 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S1 ; Drive 4 goes forwards
M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation
M92 X99 Y99 Z400 E416.35 ; Set steps per mm
M566 X900 Y900 Z12 E120 ; Set maximum instantaneous speed changes (mm/min)
M203 X6000 Y6000 Z180 E1200 ; Set maximum speeds (mm/min)
M201 X500 Y20 Z250 E250 ; Set accelerations (mm/s^2)
M906 X800 Y800 Z800 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 X295 Y295 Z300 S0 ; Set axis maxima

;Individual Z motors
M584 X0 Y1 Z2:5:6
M671 X10:140:290 Y95:10:95 S1 ; leadscrews at left, middle and right

; Endstops
;M574 X1 Y2 S0 ; Set active low endstops
M574 X1 Y2 S3 ; Set active sensorless homing endstops

; Z-Probe
M574 Z1 S2 ; Set endstops controlled by probe
M558 P5 H5 F120 T6000 ; Set Z probe type to unmodulated and the dive height + speeds
G31 P500 X-10 Y75 Z1.32 ; Set Z probe trigger value, offset and trigger height
M557 X10:290 Y55:290 S35 ; Define mesh grid

; Heaters
M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1
M143 H1 S280 ; Set temperature limit for heater 1 to 280C
M307 H7 A-1 C-1 D-1 ; Disable 7th Heater

; Fans
M106 P0 S0.3 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F500 H1 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on
M106 P2 S1 I0 F500 H1 T45 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 ; 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

; Automatic saving after power loss is not enabled

; Custom settings are not configured

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool on Mon Mar 26 2018 16:38:56 GMT+0200 (W. Europe Daylight Time)
M400 ;make sure everything has stopped before we make changes
M913 X50 Y50 ;Drop current to 50%
G91 ; relative positioning
G1 Z5 F1000 S2 ; lift Z relative to current position
G1 S1 X-290 Y290 F4000 ; move quickly to X or Y endstop and stop there (first pass)
G1 S1 X-290 ; home X axis
G1 S1 Y290 ; home Y axis
G1 X4 Y4 F6000 ; go back a few mm
G1 S1 X-290 F360 ; move slowly to X axis endstop once more (second pass)
G1 S1 Y290 ; then move slowly to Y axis endstop
G90 ; absolute positioning
G1 X150 Y150 F600 ; go to first bed probe point and home Z
G30 ; home Z by probing the bed
M400 ;make sure everything has stopped before we resett the motor currents
M913 X100 Y100 ; motor current back to 100
;G1 Z5 F100 S2 ; uncomment this line to lift the nozzle after homing

; homey.g
; called to home the y axis
;
M400 ; make sure everything has stopped before we make changes
M913 Y50 ; drop motor currents to 50%
M915 X Y S3 R0 ; set sensitivity to +3 unfiltered
G91 ; use relative positioning
G1 Z5 F6000 S2 ; Lift Z
G1 S1 Y295 F1800 ; move Y all the way left and stop at end
G1 Y-5 F1800 ; move to edge of glass
G1 Z-5 F6000 S2 ; lower Z again
G90 ; absolute positioning

; homex.g
; called to home the X axis
;
M400 ; make sure everything has stopped before we make changes
G1 Z5 F6000 S2 ; Lift Z
M913 X50 ; drop motor currents to 50%
M915 X Y S3 R0 ; set sensitivity to +3 unfiltered
G91 ; use relative positioning
G1 S1 X-295 F1800 ; move X all the way left and stop at end
G1 Z-5 F6000 S2 ; lower Z again
G90 ; absolute positioning