Power Failure Resume Skipping

selva_tvi

Hi all

Board - Duet 3 MB 6HC V1.02 with RPI 3B.
DSF Version: 3.4.5
Firmware: RepRapFirmware for Duet 3 MB6HC 3.4.5 (2022-11-30)
Duet Web Control 3.4.5

Panel Due 5i - Firmware - 3.4.x

After the power failure, we resumed it using M916. Homing sequence is given in a seperate file called 'pwrresumehome.g'. All are working without any issues.

But the X and Y is skipping by 0.5-1mm. It is very strange.

We tried multiple ways - Belt tightening, slowly home after M916.

Tried upgrading the Firmware to MB6HC 3.5.0-beta.4 also.

Still, the skipping is there.

Previously we have used Duet 3 Wifi and Duet 3 XD. we didnt face any issue.

I have uploaded all my sys files here.
homeall.g config.g pwrresumehome.g

config-override.g deployprobe.g

resume.g retractprobe.g resurrect-prologue.g resurrect.g

@dc42 @Phaedrux @jay_s_uk Kindly support. Tomorrow this machine has to be installed at a customers location

droftarts

@selva_tvi comparing your homeall.g and pwrresumehome.g, they are quite different, and use different speeds. I would make them the same for X, Y and U, if possible, which should make them more consistent.
homeall.g:

; homeall.g
; called to home all axes
;
; generated by RepRapFirmware Configuration Tool v3.3.16 on Sun May 28 2023 12:00:44 GMT+0530 (India Standard Time)
T0 P0                        ; Select Left hotend
M280 P0 S160                 ; Reset Bed sensor
G91                          ; relative positioning
G1 H2 Z5 F9000               ; lift Z relative to current position
G1 H1 X-405 Y-405 U405 F9000 ; move quickly to X or Y endstop and stop there (first pass)
G1 H1 X-405                  ; home X axis
G1 H1 U400                   ; home U axis
G1 H1 Y-405   F9000               ; home Y axis
G1 Y5 F1200
G4 P500
G1 X5 U-5                    ; go back a few mm
G1 H1 X-20 F360              ; move slowly to X axis endstop once more (second pass)
G1 H1 U20                   ; then move slowly to Y axis endstop
G1 H1 Y-20                    ; move slowly to U axis endstop
G90                          ; absolute positioning
G1 X35 Y15 F9000             ; go to first bed probe point and home Z
G30                          ; home Z by probing the bed

; Uncomment the following lines to lift Z after probing
;G91                    ; relative positioning
;G1 Z5 F100             ; lift Z relative to current position
;G90                    ; absolute positioning

pwrresumehome.g

; pwrresumehome.g
; called to home XYU axis after power failure
;

T0 P0                   ; Select Tool 0 before homing
M579 U1
G91                     ; relative positioning
G1 H2 Z5 F3000          ; lift Z relative to current position
;G1 H1 X-405 Y-405 U405 F600 ; move quickly to X or Y endstop and stop there (first pass)
G1 H1 X-405 F2400        ; home X axis
G1 H1 U405              ; home U axis
G1 H1 Y-405             ; home Y axis

G91 ; relative axis movement
G1 Z-3 F500 ; up 3mm
G90 ; absolute axis movement

;G1 Y5 F300
;G4 P500
;G1 X5 U-5                    ; go back a few mm
;G1 H1 X-20 F360              ; move slowly to X axis endstop once more (second pass)
;G1 H1 U20                   ; then move slowly to Y axis endstop
;G1 H1 Y-20                    ; move slowly to U axis endstop

Ian

selva_tvi

@droftarts Thanks. Previously homeall and pwrresumehome.g was with the same speed and sequence.

When we faced the skipping issue, then intentionally in 'pwrresumehome.g' we reduced the speed.

selva_tvi

@dc42 @droftarts @Phaedrux Kinldy help.

I tried all the possible ways. Cross checked the belt tightening, Endstop position (tight only).

But stil the skipping is happening, It moves X by 1mm and Y by -1mm approximate.

droftarts

@selva_tvi is the movement towards the endstops for each axis? If so, I expect the move that the XY move from home back to the resume point is too fast, and it is skipping steps.

Ian