Totally confused about bltouch setup

bastibasti

Hey guys,

normally I'm not such a terrible noob about tech stuff, but I might need your help.

I have connected a bltouch, and it also selftests after power up.

I have connected the servo pin to PIN8 of my Duett 2 Wifi board (Heater 3)

This is my config:

; Endstops
M574 X1 S1 P"!xstop"                            ; configure active-LOW endstop for low end on X via pin xstop
M574 Y1 S1 P"!ystop"                            ; configure active-LOW endstop for low end on Y via pin ystop
M574 Z1 S1 P"!zstop"                            ; configure active-LOW endstop for low end on Z via pin zstop

; Z-Probe
; BLTouch - Heaters
M558 P5 C"^zprobe.in" H5 F120 T4000            ; set Z probe type to switch and the dive height + speeds
M307 H3 A-1 C-1 D-1 ; Disable the 3rd Heater to free up 
M280 P3 S10 I1
G31 P500 X0 Y0 Z0                            ; set Z probe trigger value, offset and trigger height
M557 X25:205 Y25:175 S20                       ; define mesh grid

As you can see I'm still using the old Z-Switch maybe this is the problem. However, I also created a bltouch_selftest macro I have tried inverted and not inverted, but no success here. Measuring the pin, it shows a constant 3.6V, so i take it the PWM output might not be working.

M280 P3 S120 I1;

I have also tried to enter the command via the command prompt but it doesnt help

Any suggestion, where to start? I guess calibrating etc makes no sense, when not even the self-test is working

thanks in advance and have a nice evening

Basti

Phaedrux

What firmware version are you using? Please send M115 to check.

Your config.g is using a mish mash of syntax from RRF2 and RRF3.

droftarts

@bastibasti From the look of your endstop configuration, you're using RepRapFirmware 3, but your BLTouch configuration is for RRF 2. So, first, what firmware are you running? Send M115 and post the response.

If it's RRF 3, see this section: https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Software_setup_RepRapFirmware_Num_3

Your config should look something like:

; Z-Probe
M950 S0 C"exp.heater3"                         ; create servo pin 0 for BLTouch
M558 P9 C"^zprobe.in" H5 F120 T6000            ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X0 Y0 Z2.5                            ; set Z probe trigger value, offset and trigger height

deployprobe.g should contain just:

M280 P0 S10 ; deploy BLTouch

retractprobe.g should contain just:

M280 P0 S90 ; retract BLTouch

Your homeall.g and homez.g files should contain G30 to home z rather than a G1 H1 Z move, which would use the endstop.

Wiring: https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Duet_2_WiFi_Ethernet_without_a_Duex_2_or_Duex_5_expansion_board

Conduct these test BEFORE homing (rather than smashing your hotend repeatedly into the bed when it doesn't work): https://duet3d.dozuki.com/Wiki/Test_and_calibrate_the_Z_probe

Ian

bastibasti

Hey guys,
good morning

M115
FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 3.0 ELECTRONICS: Duet WiFi 1.02 or later FIRMWARE_DATE: 2020-01-03b3

bastibasti

So,

from my understanding of your config example above, I have to use the bltouch for Z-Homing from now on?

How does the firmware handle this? -> My problem is that the probe is offset -40 something in the Y direction, so after homing X and Y, the probe is "in the air".

My original idea was, to use the probe for bed levelling measurement and the endstop switch for homing. if that is not possible, i have to find another solution

droftarts

@bastibasti yes, you can continue to use the z endstop for homing if you prefer; just leave the homing files as they are. The probe will be used for G29, G30 and G31.

However, the Y offset doesn’t matter, as you can move X and Y to anywhere you want, because they are homed first. So just move, ideally to the centre of the bed, then home Z there, using the probe.

Ian

Phaedrux

@bastibasti said in Totally confused about bltouch setup:

FIRMWARE_VERSION: 3.0

You should update your firmware to the latest stable RRF3 version as well.

Upload this zip file to the system tab in DWC. Don't extract it first.

https://github.com/Duet3D/RepRapFirmware/releases/download/3.2.2/Duet2and3Firmware-3.2.2.zip

After X and Y are homed you can use a G1 X Y command to place the probe at the center of the bed and then use G30 to home Z. See here for some examples files.

https://duet3d.dozuki.com/Wiki/ConfiguringRepRapFirmwareCartesianPrinter#Section_Homing_files

bastibasti

@droftarts said in Totally confused about bltouch setup:

leave the homing files as they are. The probe will be used for G29, G30 and G31.
However, the Y offset doesn’t matter, as you can move X and Y to anywhere you want, because they are homed first. So just m

Ok, thank you thats understood! I think its better to have the z endstop as a security measure. I will try to calibrate the Z offset and then measure the X/Y. Looking forward how the grid measurement will look like.

Phaedrux

It's fine to use the endstop for initial homing, but you must use G30 and the probe before G29 or G29 S1 and before the print starts otherwise there can be unexpected Z offsets.

bastibasti

@phaedrux

Thank you, I upgraded the firmware

M115
FIRMWARE_NAME: RepRapFirmware for Duet 2 WiFi/Ethernet FIRMWARE_VERSION: 3.2.2 ELECTRONICS: Duet WiFi 1.02 or later FIRMWARE_DATE: 2021-02-11

now fiddling around with the settings. I'm sure I will annoy you guys again :-))