levelling and mesh

MikeDC

Hi,
I am not sure what is going on here,
I was on 3.2.2 using only the duet3 mainboard with 3 z motors, but due to some upgrades I needed to move the Z motors to the 3HC expansion board.

After moving them to the 3HC, I suffered some CAN bus issues where Z moves were being delayed.
This got me to try Beta7 firmware
Z moves are working correctly now.
However my problem now is my bed levelling and mesh.

While on 3.2.2 my mesh was like this.

Now on beta7 when I perform a homeall then level then a mesh it is like this.

And looking at the heightmap.csv the bed gradually gets higher from front to the back of the bed almost as if there is something off with the bed levelling.

RepRapFirmware height map file v2 generated at 2022-01-05 01:07, min error -0.068, max error 0.193, mean 0.046, deviation 0.072
axis0,axis1,min0,max0,min1,max1,radius,spacing0,spacing1,num0,num1
X,Y,30.00,314.00,5.00,295.00,-1.00,40.57,41.42,8,8
-0.002, -0.032, -0.062, -0.064, -0.036, -0.061, -0.017, 0.022
0.018, -0.004, -0.041, -0.052, -0.037, -0.068, -0.042, -0.022
0.031, 0.005, -0.037, -0.038, -0.016, -0.051, -0.011, 0.014
0.083, 0.049, 0.011, 0.007, 0.008, -0.020, 0.010, 0.039
0.109, 0.076, 0.037, 0.024, 0.048, 0.014, 0.069, 0.101
0.179, 0.139, 0.095, 0.086, 0.094, 0.066, 0.101, 0.139
0.170, 0.133, 0.090, 0.089, 0.126, 0.086, 0.127, 0.182
0.193, 0.136, 0.093, 0.086, 0.122, 0.082, 0.119, 0.178

Relevent parts of my config's
Config.g
; Drives
M569 P0.0 S0
M569 P0.1 S0
M569 P0.2 S0
M569 P0.4 S0
M569 P0.5 S0
M569 P1.0 S1 ; Z front Left
M569 P1.1 S1 ; Z Rear Centre
M569 P1.2 S1 ; Z Front Right

; Drive Selection
M584 X0.0:0.5 Y0.1:0.4 Z1.0:1.1:1.2 E2
M671 X-16.698:172.011:360.72 Y2.021:355.231:2.021 s2.0

; Z-Probe
M574 Z1 S2
M950 S0 C"io7.out"
M558 P9 C"^io7.in" H4.0 A3 S0.02 F200 T10000
G31 P500 X25 Y-10 Z2.058
M557 X30:314 Y5:295 P8

Bed.g
M561
G28
M400
G30 P0 X23 Y-10 Z-99999 ; LF
G30 P1 X23 Y310 Z-99999 ; LR
G30 P2 X330 Y310 Z-99999 ; RR
G30 P2 X330 Y-10 Z-99999 S3 ; RF

I havent changed anything physically on Y or Z axis or the bed itself other to moving the motor connections from the duet3 to the 3hc expansion and upgrading the firmware.
When I homeall I home to the centre of the bed
Am I missing something that would cause the back to be higher than the front ?

Thanks
Mike

Phaedrux

@mikedc said in levelling and mesh:

After moving them to the 3HC, I suffered some CAN bus issues where Z moves were being delayed.

This is expected at the moment.

Due to CAN latency the motors connected to expansion boards may slightly overshoot the position at which the endstop or Z probe was triggered. This would not usually matter for an endstop switch, but it does mean that if the Z motor(s) is/are connected to an expansion board then repeated probing with a Z probe (e.g. for mesh bed compensation) is not advisable. This will be fixed in a future release
https://duet3d.dozuki.com/Wiki/Duet_3_firmware_configuration_limitations

@mikedc said in levelling and mesh:

G30 P0 X23 Y-10 Z-99999 ; LF
G30 P1 X23 Y310 Z-99999 ; LR
G30 P2 X330 Y310 Z-99999 ; RR
G30 P2 X330 Y-10 Z-99999 S3 ; RF

It looks like you're using P2 twice.

MikeDC

Ooops I think i messed up with copying it
the last one is P3

I just rechecked it and ran the home, level and mesh again, its still doing the same

Phaedrux

@phaedrux said in levelling and mesh:

This is expected at the moment.

Due to CAN latency the motors connected to expansion boards may slightly overshoot the position at which the endstop or Z probe was triggered. This would not usually matter for an endstop switch, but it does mean that if the Z motor(s) is/are connected to an expansion board then repeated probing with a Z probe (e.g. for mesh bed compensation) is not advisable. This will be fixed in a future release
https://duet3d.dozuki.com/Wiki/Duet_3_firmware_configuration_limitations

I still think you're experiencing this limitation.

MikeDC

@phaedrux
Thankyou,

I am pretty sure you are right, with 3.3 it was far worse than the B7
But as it is, I think I will have to find an alternate way to use 7 motors.

If the motors are delaying then i cannot put x or y or e here either as they will all have differing issues.

MikeDC

Today the bed wont even level.
I have pages and pages of this where I have been trying.

Phaedrux

It telling you that the deviation is greater than you have it configured to try and fix.

M671 X-16.698:172.011:360.72 Y2.021:355.231:2.021 s2.0

The S2 at the end tells it how much it can try and correct.

MikeDC

S2 is huge, ive always ran S0.02 previously

Phaedrux

Are you repeating the process or is it auto repeating with conditional gcode?

Can you upload your actual config.g, homeall.g, bed.g etc?

MikeDC

@Phaedrux here they are
config.g

; Configuration file for Duet 3 (firmware version 3)
; executed by the firmware on start-up
;
; generated by RepRapFirmware Configuration Tool v3.1.10 on Wed Dec 16 2020 20:30:34 GMT+0000 (Greenwich Mean Time)

; General preferences
G90                                                                  ; send absolute coordinates...
M83                                                                  ; ...but relative extruder moves
M550 P"Bustamove"                                     ; set printer name
M669 K1                                                          ; select CoreXY mode

G4 S5                                                               ;  Wait for CAN Bus

; Drives
M569 P0.0 S0                                           		; Drive 0 Left Motor goes backwards
M569 P0.1 S0                                           		; Drive 1 Right Motor goes backwards
M569 P0.2 S0                                           		; Drive 2 Extruder motor goes forwards
;M569 P0.3 S1					     							; Drive 3 Not Used
M569 P0.4 S0					     							; Drive 4 Y2 motor goes backward
M569 P0.5 S0					    							; Drive 5 X2 motor goes backward
M569 P1.0 S1					     							; Drive 3 Zleft motor goes forward
M569 P1.1 S1					     							; Drive 4 Zrear motor goes forward
M569 P1.2 S1					    							; Drive 5 Zright motor goes forward

; Drive Selection 
M584 X0.0:0.5 Y0.1:0.4 Z1.0:1.1:1.2 E2				     ; Three Z motors connected to driver outputs 1.0, 1.1 and 1.2 (Needs to be posted before M350 microstepping)
M671 X-16.698:172.011:360.72 Y2.021:355.231:2.021 s2.0   ; Z LIFT POINT POSITIONS
M350 X16 Y16 Z16 E8 I0                                   ; configure microstepping without interpolation
M92 X160.00 Y160.00 Z800.00 E359.90                 ; set steps per mm
M566 X800.00 Y800.00 Z60 E1400                  	     ; Set maximum instantaneous speed changes (mm/min)
M203 X50000.00 Y50000.00 Z1000.00 E10000.00              ; Set maximum speeds (mm/min) / feedrate
M201 X8000.00 Y8000.00 Z90.00 E800 				         ; Set accelerations (mm/s^2)
M906 X1800.00 Y1800.00 Z1100.00 E600 I30         	     ; Set motor currents (mA) and motor idle factor in per cent

M84 S30                                                  ; Set idle timeout
M593 F38.1                                               ; cancel ringing at 65.5Hz -  print speed / distance between peaks of ringing

; Axis Limits
M208 X-2 Y-12 Z-0.3 S1                                   ; set axis minimum
M208 X315 Y325 Z320 S0                                   ; set axis maximum

; Endstops
M574 X1 S1 P"io1.in"                                  ; configure active-high endstop for low end on X via pin io0.in
M574 Y1 S1 P"io2.in"                                  ; configure active-high endstop for low end on Y via pin io1.in

; Z-Probe
M574 Z1 S2                                            ; configure Z-probe endstop for low end on Z
M950 S0 C"io7.out"                                    ; create servo pin 0 for BLTouch
M558 P9 C"^io7.in" H6.0 A3 S0.02 F300 T10000          ; set Z probe type to bltouch and the dive height + speeds
;M558 H30                                             ;*** Remove this line after delta calibration has been done and new delta parameters have been saved
G31 P500 X25 Y-10 Z2.058                              ; set Z probe trigger value, offset and trigger height
M557 X25:330 Y-10:305 P8                              ; define mesh grid

; Heaters
M308 S0 P"temp0" Y"thermistor" T100000 B4138         ; configure sensor 0 as thermistor on pin temp0
M950 H0 C"out0" T0                                   ; create bed heater output on out0 and map it to sensor 0
M307 H0 B1 S1.00                                     ; enable 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"temp1" Y"thermistor" T4606017 B5848 C5.548428e-8 ; DYZE HIGH TEMP 500C Thermister
M308 S1 P"temp1" Y"pt1000" A"nozzle_temp"            ; configure sensor 1 as PT1000 on pin temp1
M950 H1 C"out1" T1                                   ; create nozzle heater output on out1 and map it to sensor 1
; old M307 H1 R2.822 C405.600:226.700 D6.90 S1.00 V24.7 B0 ; PT1000 Autotuned
M307 H1 R2.339 C413.3 D7.08 S1.00 V23.6 B0
;M307 H1 B0 S1.00                                    ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S350                                         ; set temperature limit for heater 1 to 350C 

; Fans
M950 F0 C"out7" Q500                                 ; create fan 0 on pin out7 and set its frequency
M106 P0 S0 H-1                                       ; set fan 0 value. Thermostatic control is turned off

;M308 S3 Y"drivers" A"DRIVERS"                        ; setup a virtual temperature sensor for the Drivers:
M308 S4 Y"mcu-temp" A"MCU"                           ; setup a virtual temperature sensor for the MCU:
M950 F1 C"!out4+out4.tach" A"MCU" Q25000             ; create fan 1 on pin out4 - figure out frequency rqd
M106 P1 S1 X1 B0.3 T35:50 H3:4 L0.3                  ; set fan 1 value. Thermostatic control is turned on

; Tools
M563 P0 S"Volcano" 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

; Miscellaneous
M575 P1 S1 B57600                                    ; enable support for PanelDue
M501                                                 ; load saved parameters from non-volatile memory
M911 S22 R23.5 P"M913 X0 Y0 G91 M83 G1 Z3 E-5 F1000" ; set voltage thresholds and actions to run on power loss
M912 P0 S-4.5                                        ; MCU Calibration

; Safety Contactor For Heatbed
; Use Gcodes in start print and end print and macros for pre-heating bed levelling etc
; M42 P2 S1                                          ; to turn contactor on
; M42 P2 S0                                          ; to turn contactor off
M950 P2 C"out3"                                      ; set out3 to heatbed safety contactor
M42 P2 S0                                            ; set heatbed contactor off
T0

bed.g , I have played with this a little tonight

; bed.g
; called to perform automatic bed compensation via G32
;
; generated by RepRapFirmware Configuration Tool v3.1.10 on Wed Dec 16 2020 20:30:34 GMT+0000 (Greenwich Mean Time)
M561 ; clear any bed transform
; If the printer hasn't been homed, home it
if !move.axes[0].homed || !move.axes[1].homed || !move.axes[2].homed
  G28
; Probe the bed and do auto calibration
G1 X25 Y-20 Z10 F9000        ; go to just above the first probe point
while true
  if iterations = 5
    M291 P"Bed Leveling Aborted" R"Pass Limit Reached"
    abort "Bed Leveling Aborted - Pass Limit Reached"
; run leveling pass
  G30 P0 X25 Y-20 Z-99999     ; LF
  if result != 0
    continue
  G30 P1 X25 Y300 Z-99999     ; LR
  if result != 0
    continue
  G30 P2 X330 Y300 Z-99999    ; RR
  if result != 0
    continue
  G30 P3 X330 Y-20 Z-99999 S3 ; RF
  if result != 0
    continue
  ; check results - exit loop if results are good
  if move.calibration.initial.deviation <= 0.024
    break
  echo "Repeating calibration because deviation is too high (" ^ move.calibration.initial.deviation ^ "mm)"
; end loop
 
echo "Auto calibration successful, deviation", move.calibration.final.deviation ^ "mm"
G1 X0 Y0 Z10                ; move front left

homeall.g

; homeall.g
; called to home all axes
;
M98 P"homex.g" ; Home X
M98 P"homey.g" ; Home Y
M98 P"homez.g" ; Home Z

homex.g and homey.g are basically the same as each other

; homex.g
; called to home the X axis
;
; generated by RepRapFirmware Configuration Tool v3.1.10 on Wed Dec 16 2020 20:30:34 GMT+0000 (Greenwich Mean Time)
G91               ; relative positioning
G1 H2 Z5 F9000   ; lift Z relative to current position
G1 H1 X-345 F9000 ; move quickly to X axis endstop and stop there (first pass)
G1 X5 F9000       ; go back a few mm
G1 H1 X-345 F300  ; move slowly to X axis endstop once more (second pass)
G1 H2 Z-5 F9000  ; lower Z again
G90               ; absolute positioning

homez.g

; homez.g
; called to home the Z axis
;
; generated by RepRapFirmware Configuration Tool v3.1.10 on Wed Dec 16 2020 20:30:34 GMT+0000 (Greenwich Mean Time)
G91                                   ; relative positioning
G1 H2 Z5 F9000                        ; lift Z relative to current position
G90                                   ; absolute positioning
G1 X145 Y155 F9000                    ; move probe to centre of the bed
G30                                   ; home Z by probing the bed

; Uncomment the following lines to lift Z after probing
G91                                  ; relative positioning
G1 Z5 F9000                          ; lift Z relative to current position
G90                                  ; absolute positioning

Phaedrux

@mikedc said in levelling and mesh:

if move.calibration.initial.deviation <= 0.024

It looks like your conditional is doing what you're asking.

Did you mean to use 0.24 instead?

MikeDC

@phaedrux

No i was using 0.02 I increased it to 0.024 where i was playing.

it used to always be around 0.016 so 0.02 was enough
now the lowest i can get it is 0.049 but more often it is anywhere between 0.071 and 0.11

Phaedrux

If you do a repeated G30 S-1 test at your probe points are the results consistent?

Is it possible to move the Z motors to the mainboard?

Marcossf

@MikeDC @Phaedrux Have a look at the David's answer in our thread about CAN delays with external boards:

@dc42 said:

I have put preliminary firmware that resolves this issue at https://www.dropbox.com/sh/cx760ysonlzzkjd/AACfsVfX4olHipuqmbWut5EKa?dl=0. Please test this firmware with care because I have only tested it using Duet 3 MB6HC + EXP3HC (the Z motor was connected to the EXP3HC).

If you are running your Duet with an attached Raspberry Pi then you must upgrade to RRF 3.4.0beta7 from the package server BEFORE you use these files.

Unfortunately we couldn't test it yet, so it's a good start point to see if this issue is addresed.

Best,

rjenkinsgb

@marcossf

One simple change that may help is just reduce the probing speed a lot, so any delays result in smaller errors.

In the config you posted earlier it is 300; try 50 or even less and see how that works?

I only use 60 even with a directly wired BLTouch!

As long as the clearance height is not excessive, it should not make all that much difference in speed but could increase accuracy a lot.

MikeDC

@phaedrux

Ok with Z on the 3HC they was definately not consistent

I have now moved the 2 Y motors temporarily to the 3HC and moved the 3 Z motors back to the mainboard

I think this is clearly showing it a 3HC can issue
consistent probing even if its not the 0.016 i was getting previously
but at least its not going as high as 0.71-0.11 now and look at the difference in the mesh, the 0.2mm difference front to back is gone.

MikeDC

This post is deleted!

MikeDC

@marcossf said in levelling and mesh:

@MikeDC @Phaedrux Have a look at the David's answer in our thread about CAN delays with external boards:

@dc42 said:

I have put preliminary firmware that resolves this issue at https://www.dropbox.com/sh/cx760ysonlzzkjd/AACfsVfX4olHipuqmbWut5EKa?dl=0. Please test this firmware with care because I have only tested it using Duet 3 MB6HC + EXP3HC (the Z motor was connected to the EXP3HC).

If you are running your Duet with an attached Raspberry Pi then you must upgrade to RRF 3.4.0beta7 from the package server BEFORE you use these files.

Unfortunately we couldn't test it yet, so it's a good start point to see if this issue is addresed.

Best,

I will definately test these files next thankyou

MikeDC

@rjenkinsgb said in levelling and mesh:

@marcossf

One simple change that may help is just reduce the probing speed a lot, so any delays result in smaller errors.

In the config you posted earlier it is 300; try 50 or even less and see how that works?

I only use 60 even with a directly wired BLTouch!

As long as the clearance height is not excessive, it should not make all that much difference in speed but could increase accuracy a lot.

I have already tried this, It doesnt help the inconsistancy,
Thankyou for the suggestion tho

engikeneer

@mikedc said in levelling and mesh:

If the motors are delaying then i cannot put x or y or e here either as they will all have differing issues.

I believe the firmware limitation is purely limited to probing moves as the motors will keep moving until the probe triggers and register their position (I.e. an unplanned event), whereas normal xy moves are all preplanned so can be synchronised between the boards. This seems to match what you are seeing

levelling and mesh

Robert J.