Probing issue ?

baird1fa

Hello all, I just updated my duet 2 WiFi to the latest 3.4.0-RC1 and I have had an issue with the sensorless homing, I think I have got that sorted out but I decided that I wanted to make an adjustment to the start.g and my bed.g in how it probes the bed and I think I found an issue with the M558 and G31 commands for setting the probe.

Because my printer has a large Z axis that can't move super fast I have in my Bed.g a G0 command to bring the bed up quickly to 10mm. Then it probes the bed to set Z at the probe trigger height and then proceeds to run the G29 bed mesh. Since the update and the issue with the sensorless homing I thought I would implement a G38.2 probe to bring the bed up, but that uses the probing speed for its feed rate. I did the same thing on my CNC router and added the M558 command to speed up the probe move for a first pass then back off a few mm reset the M558 speed and do a second probe slower using the G30. After all that I run the G29 to get the bed mesh.

The issue is that after updating the M558 the printer tried to probe off the bed, essentially ignoring the G31 parameters. To resolve the issue I have to reissue the G31 commands after the M558. Is that the intended behaviour or is that bug?

Regards.

Phaedrux

Please share your actual gcode used.

baird1fa

@phaedrux

Here is the Start.g that I'm using which shows the use of the M558 and the G31. If I remove the G31 from this macro, the probe will not probe the bed, it will move outside of the limits.

; This will run at the start of all prints
; If the printer hasn't been homed, home it
if !move.axes[2].homed 
  G28 Z
if !move.axes[0].homed 
   G28 X
if !move.axes[1].homed 
   G28 Y
G1 X0 Y0 F12000 ; move to center of bed
M558 P9 C"^zprobe.in" H5 F6000 T9000    ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-42.5 Y-8.00 Z2.8             ; set Z probe trigger value, offset and trigger height
G38.2 Z0								; Probe bed quickly
;G1 Z10 F1000							; Move bed close to nozzle for probing
M558 P9 C"^zprobe.in" H5 F300 T9000     ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-42.5 Y-8.00 Z2.8             ; set Z probe trigger value, offset and trigger height
G1 Z10 F1000							; Back off 10mm

G32			; Run Bed.g which probes the bed and sets the mesh file

Here is config.g

; Configuration file for Duet WiFi (firmware version 3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.1.10 on Sun Dec 20 2020 17:43:31 GMT-0600 (Central Standard Time)

; General preferences
G90                                                ; send absolute coordinates...
M83                                                ; ...but relative extruder moves
M550 P"Ender 5 Pro"                                ; 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 S0                                         ; physical drive 0 goes backwards
M569 P1 S0                                         ; physical drive 1 goes backwards
M569 P2 S1                                         ; physical drive 2 goes forwards
M569 P3 S1                                         ; physical drive 3 goes forwards
M584 X0 Y1 Z2 E3                                   ; set drive mapping
M350 X32 Y32 Z16 E32 I1                            ; configure microstepping with interpolation
M92 X160.00 Y160.00 Z794.76 E276.00               ; set steps per mm
M566 X1000.00 Y1000.00 Z300.00 E400.00               ; set maximum instantaneous speed changes (mm/min)
M203 X12000.00 Y12000.00 Z1200.00 E1200.00           ; set maximum speeds (mm/min)
M201 X1500.00 Y1500.00 Z50.00 E250.00                ; set accelerations (mm/s^2)
M906 X650 Y800 Z1200 E650 I30                      ; set motor currents (mA) and motor idle factor in per cent
M84 S30                                            ; Set idle timeout

; Axis Limits
M208 X-115 Y-115 Z-8 S1                            ; set axis minima
M208 X115 Y115 Z506 S0                             ; set axis maxima

; Endstops
M574 X2 S1 P"xstop"                                ; configure active-high endstop for high end on X via pin xstop
M574 Y2 S1 P"ystop"                                ; configure active-high endstop for high end on Y via pin ystop
M574 Z2 S3											; configure motor stall for Z max
M915 Z S3 F0 H600 R0								; configure stall detection

; Z-Probe
M950 S0 C"exp.heater3"                             ; create servo pin 0 for BLTouch
M558 P9 C"^zprobe.in" H5 F300 T9000                ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-42.5 Y-8.00 Z2.8                       ; set Z probe trigger value, offset and trigger height
M557 X-105:65 Y-105:65 S34                         ; define mesh grid

; Filament sensor
M591 P2 C"e1stop" S1 D0 						   ; filament monitor connected to E0 endstop

; 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
M307 H0 B0 S1.00                                   ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0                                            ; map heated bed to heater 0
M143 H0 S120                                       ; set temperature limit for heater 0 to 120C
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
M307 H1 B0 S1.00                                   ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S280                                       ; set temperature limit for heater 1 to 280C

;Virtual Heaters
M308 S4 Y"mcu-temp" A"MCU"				           ; create mcu temperature
M308 S5 Y"drivers" A"Stepper driver"			   ; create driver temperature

; Fans
M950 F0 C"fan0" Q50                              ; create fan 0 on pin fan0 and set its frequency Board cooling fan
M106 P0 L50 T30:45 H4:5                                ; set fan 0 value. Thermostatic control is turned on proportional to the mcu temp
M950 F1 C"fan1" Q500                               ; create fan 1 on pin fan1 and set its frequency Part cooling fan
M106 P1 S0 H-1                                     ; set fan 1 value. Thermostatic control is turned off
M950 F2 C"fan2" Q500                               ; create fan 2 on pin fan2 and set its frequency Heat break fan
M106 P2 S0 H1 T45                                  ; set fan 2 value. Thermostatic control is turned on

; Tools
M563 P0 D0 H1 F1                                   ; 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 are not defined

; Miscellaneous
M572 D0 S0.05										; Set pressure advance
M501                                               ; load saved parameters from non-volatile memory
M911 S23 R24 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; set voltage thresholds and actions to run on power loss
T0                                                 ; select first tool

Phaedrux

@baird1fa said in Probing issue ?:

If I remove the G31 from this macro, the probe will not probe the bed, it will move outside of the limits.

This is because you're using a full M558 command. Every time you do that you need to resend the G31.

If you just want to alter a single parameter of the M558, only call that parameter out.

Ex. M558 F300

Then you won't need to include the G31 at all outside of config.g

baird1fa

@phaedrux Good to know. Thanks.