Configuration file for Duet
; executed by the firmware on start-up
; WorkBee Firmware Version 1.0.7

; Configure Connection - ENABLE ONLY ONE OF THE BELOW THREE
M552 S1 ; Enable Wifi Network
;M552 S2 ; Enable Access Point Mode
;M552 S1 P192.168.2.12 ; Enable Ethernet - Change IP Address to suit

; - - - - - - - - - - - - - - - - - - - -

; DO NOT CHANGE ANY OF SETTINGS BELOW
; TO MAKE A CHANGE, COPY THE LINE OF CODE, PASTE IT INTO customconfig.g. THE CHANGE CAN THEN BE MADE IN customconfig.g
; ANY ADDITIONAL SETTINGS SHOULD BE PUT IN customconfig.g

; General preferences
M453 ; Put the machine into CNC Modes
M550 PWorkBee CNC Machine ; Set machine name
G90 ; Set absolute coordinates

; Network
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet

; Configure Drives
M584 X0 Y1:3 Z2 U3 P3; Apply drive mapping to axes
M569 P0 S0 ; Drive 0 goes forwards
M569 P1 S0 ; Drive 1 goes forwards
M569 P2 S0 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards

; Configure Axes
M92 X80.083 Y80.014 Z406.65 U80.014 ; Set steps per mm
M350 X16 Y16 Z8 U16 I1 ; Configure microstepping
M566 X500 Y500 Z500 U500 ; Set maximum instantaneous speed changes (mm/min)
M203 X6000 Y6000 Z2000 U6000 ; Set maximum speeds (mm/min)
M201 X100 Y100 Z100 U100 ; Set accelerations (mm/s^2)
M906 X2300 Y2300 Z1900 U2300 I100 ; Set motor currents (mA)

; Configure Axis Limits
M208 X0 Y0 Z0 U0 S1 ; Set axis minima
M208 X720 Y1260 Z120.5 U1260 S0 ; Set axis maxima

; Configure Endstops
M574 X1 Y1 Z2 U1 S1 ; Set active low endstops

; Other Settings
M140 H-1 ; Disable heated bed
M564 S1 H1 ; Disable jog commands when not homed
M911 S21.0 R23 P"G91 G1 Z3 F1000" ; Configure power loss resume
M501 ; Load Stored Parameters
;M98 Pcustomconfig.g ; Execute custom config settings

I am running a custom built cnc machine with a duet wifi utilizing the Workebee CNC web controller.

I home the machine, instruct it to go to a point on the Y axis, then mark that point, If I then instruct the machine to go in the positive direction (G1 Y800 for example) and then I command the machine to return to the original spot, I am off about 1.5 mm. ( it will be short of the spot) So the the machine will move 700mm in one direction correctly, then come back 699 instead of 700 on the return trip.

If I repeat the process but come back to the point I have marked from the negative direction it returns to the correct location. So from "below" the point the machine seems to move accurately.

I am perplexed. The machine is solid and square. Wondering if anyone else has had a similar problem or might propose a solution.

Thanks!