K40 Laser, BLTouch as autofocus with SKR 1.4T and DWC

paulg4h

Hello,

maybe someone are so kind to help me to configure the BLTouch on my K40 as autofocus to set the exact height for the laser automatically at start of a job.

Board: biquskr_1.4 (LPCWiFi)
Firmware: RepRapFirmware for LPC176x based Boards 3.2_1 (2021-01-05)
Duet WiFi Server Version: 1.25-01L-D

I setup the system as laser with:

M452 C"bed" R255 S1 F100                     ; laser uses bed pin,  PWM frequency 100Hz

And the L of the Laser Power Supply is connected to the GND of the BED MosFet

Here are my BLTouch settings in config.g

; Z-Probe
M950 S0 C"servo0"                                   ; create servo pin 0 for BLTouch
M558 P9 H6 F120 T8000 C"^probe"      ; set Z probe type to bltouch and the dive height + speeds
G31 P500 X-20 Y20 Z10.5                        ; set Z probe trigger value, offset and trigger height

Then I try to trigger the upper material with a macro which contains:

G0 F8000 X100 Y100
G38.2 Z

The issue is then that the bed lifts up but the probe is not deployed, but on power up it deploy an retract normally and with:

M280 P0 S10

it deploys manually and even the other commands for retract, reset and test are functional.

Many thank's in advance for your reply!

paulg4h

Is there no one which can support me here?

droftarts

@paulg4h For the probe, you need to check that M401 and M402 work to deploy and retract the probe; they call deployprobe.g and retractprobe.g files. See points 6 and 7 here: https://duet3d.dozuki.com/Wiki/Connecting_a_Z_probe#Section_Software_setup_RepRapFirmware_Num_3

Test that, when you send M401, the probe deploys. A light touch on the probe should also show the Z-probe value going to 1000 in the DWC dashboard.

I'm not sure about probing using G38.2. See https://duet3d.dozuki.com/Wiki/Gcode#Section_G38_2_to_G38_5_Straight_Probe

I think you need to specify coordinates to probe, and perhaps add P0 so it definitely knows that you mean BLTouch.

Ian

paulg4h

@droftarts
Many thank's for your suggestion I will try it.