Delta calibration G32 Offset issue

[Serhii]

Hello everyone.
I would like to ask for some help with the following issue:

Setup:
[3D printer]
I have a Kossel anyCubic 3D printer with a Duet3D board.
[Sensor]
A mechanical switch.
[bed.g]
M561 ; clear any bed transform
G28 ; home all towers
G30 P0 X0.00 Y90.00 Z-99999 H-14.82
G30 P1 X57.85 Y68.94 Z-99999 H-14.82
G30 P2 X88.63 Y15.63 Z-99999 H-14.82
G30 P3 X77.94 Y-45.00 Z-99999 H-14.82
G30 P4 X30.78 Y-84.57 Z-99999 H-14.82
G30 P5 X-30.78 Y-84.57 Z-99999 H-14.82
G30 P6 X-77.94 Y-45.00 Z-99999 H-14.82
G30 P7 X-88.63 Y15.63 Z-99999 H-14.82
G30 P8 X-57.85 Y68.94 Z-99999 H-14.82
G30 P9 X0.00 Y45.00 Z-99999 H-14.82
G30 P10 X38.97 Y22.50 Z-99999 H-14.82
G30 P11 X38.97 Y-22.50 Z-99999 H-14.82
G30 P12 X0.00 Y-45.00 Z-99999 H-14.82
G30 P13 X-38.97 Y-22.50 Z-99999 H-14.82
G30 P14 X-38.97 Y22.50 Z-99999 H-14.82
G30 P15 X0 Y0 Z-99999 S6
G28 ; home all towers

Thank you in advance.

[droftarts]

@Serhii I think you’re using the H parameter of G30 incorrectly. From the Gcode dictionary

The H parameter is an optional height correction for that probe point. It allows for the Z probe having a trigger height that varies with XY position. The nominal trigger height of the Z probe (e.g. at bed centre) is declared in the Z parameter of the G31 command in the config.g file. When you probe using G30 and the probe triggers, the firmware will assume that the nozzle is at the nominal trigger height plus the value you have in the H parameter. For example, when doing delta calibration, it can account for the change in trigger height caused by effector tilt, if the vertical offset caused by the tilt has been measured.

So H parameter should be 0 unless there is a variation is Z height with XY position.

Use G31 Z… to set the probe offset ie 14.82mm. You haven’t posted your config.g or firmware version, so I don’t know how this is currently set.

Ian

[Serhii]

@droftarts Thank you for the quick replay.
I have attached my config file
config.g
Could you suggest which changes should be made?

[droftarts]

@Serhii said in Delta calibration G32 Offset issue:

Could you suggest which changes should be made?

I thought I just did! Set H to 0 in, or remove it from, the G30 commands in bed.g. Set the Z probe offset in the G31 command in config.g.

I can’t read your config.g, I’m on my phone. Post it as a text file (.txt ending) or as code in code tags.

Ian

[Serhii]

@droftarts

Some information about the board and FW

Board: Duet 2 WiFi (2WiFi)
Firmware: RepRapFirmware for Duet 2 WiFi/Ethernet 3.4.0 (2022-03-15)
Duet WiFi Server Version: 1.26

config.txt

; Z-Probe
M558 P5 C"^zprobe.in" H5 F120 T6000            ; set Z probe type to switch and the dive height + speeds
G31 P500 X0 Y0 Z14.82                          ; set Z probe trigger value, offset and trigger height
M557 R85 S20                                   ; define mesh grid

I removed the H option from the bed.g file

G30 P0 X0.00 Y90.00 Z-99999
G30 P1 X57.85 Y68.94 Z-99999
G30 P2 X88.63 Y15.63 Z-99999
...

The result looks the same

[droftarts]

@Serhii The diagram of the bed you are looking at is a mesh probe of the bed using G29, not the result of delta calibration (G32/bed.g). Running a delta calibration with the G30 H parameter set to -14.82 will affect the 'homed height' result of the delta calibration, I think, so when you then run G29, the bed looks too far away. So make sure all G30 H commands are set to H0 in bed.g, then run G32 again (to set the correct homed height) then G28 to home, then G29 for the bed mesh.

G29 runs sys/mesh.g if it exists, so you could create that with a G28 then G29 in it.

In case you haven't seen it, also see https://docs.duet3d.com/en/User_manual/Tuning/Delta_calibration

Ian

[Serhii]

@droftarts thank you for your help.

I finally got the following result: