Hello. On my machine, the z-axis is adjusted manually and I would like to be able to programmatically turn on the laser with some minimum power for an indefinite time. The option using a virtual extruder did not work for me. In addition, this still implies switching on for a short time.

RepRapFirmware for Duet 2 WiFi/Ethernet 3.4.3 (2022-10-05)

; Configuration file for Duet WiFi (firmware version 3.3)
; executed by the firmware on start-up

G90                                     
;M83                                     
M550 P"Duet"                            
M452 C"!exp.heater3" R5000 F5000        
M571 P"!exp.heater3" F200 S255

; Сеть 
M552 S0                                 
M587 S"ASUS_RT" P""            
M552 S1                                 
M586 P0 S1                               
M586 P1 S0                               
M586 P2 S0                               

; Драйвера
M569 P0 S0                              
M569 P1 S0                              
M569 P3 S1                             
M584 X0 Y1:3                            
M350 X16 Y16 I1                         
M92 X100.00 Y80.00                      
M566 X900.00 Y900.00                   
M203 X12000.00 Y12000.00               
M201 X500.00 Y500.00                   
M906 X800 Y800 I80                    
M84 S0                                

; Лимиты
M208 X0 Y0 S1                           
M208 X875 Y808 S0                      

; Стопы
M574 X1 S1 P"xstop"                     
M574 Y1 S1 P"ystop"                    
M574 Z0 S0

; Z-Probe
; Heaters

; Fans
M950 F0 C"fan0" Q500                    ; create fan 0 on pin fan0 and set its frequency
M106 P0 S0 H-1                          ; set fan 0 value. Thermostatic control is turned off
M950 F1 C"fan1" Q500                    ; create fan 1 on pin fan1 and set its frequency
M106 P1 S1 H T45                        ; set fan 1 value. Thermostatic control is turned on

; Tools
M563 P0 H1 S"Laser"
M302 P1
T0

@dc42 Is there any progress on this topic? I have a manual Z-axis adjustment and would like to be able to focus. I still haven't figured out how to do it. When using the G1 command, the laser goes out after a while, you have to run the G1 commands every time. Is there a solution to this problem?

@dc42 If my laser is 24 volts, can I connect to the PWM from the LASER/VFD output and power it from the 24v input or from the heater?

@dc42 0.9 degrees. These are Wantai motors, 2.4A with a fairly low inductance
I did not try this with a 30mm fan, but with the 4010 fan turned off, the repeatability was better. Although accuracy of 0.02 suits me, if only the accuracy of calibration affects only the first layer. If this affects print quality further layers, of course I will fight for better accuracy.

Honestly, I don’t know what can be improved in my mechanics. I installed hivin rails and haydn magnetic rods, optical stops.
the bed is a plate on the entire area of the delta .. all that comes to mind is to anchor it to the floor)

@dc42 I'll see. what about accuracy?

@dc42 thanks. I put a 30mm maglev fan and everything became fine, but another problem appeared) In the previous assembly, the yellow LED on top of it was always on during operation. He blinked randomly. Now it does not burn at all, although the heating is on and everything is printing.
By the way, I was looking for information on the network, but I could not find it - what is the error of the strain gauge? I have repeatability of the results within 0.02 mm (but I want to note that I use a klipper, although the board and the effector are a duet)

It would be more maintainable to make terminal blocks below not only for the heater, but also for fans and a thermistor. Sometimes they have to be changed and then you have two ways - to compress the molex again or to cut and twist the wire. Easier to tighten into the block

Separately, I want to note that the molex in the lower part on the thermistor and on the fans is a terrible decision. Replacing a thermistor or fan turns into a headache

@Danal In this case, the Chinese cheap fan should have influenced in the same way. It vibrated 10 times stronger, but the sensor was not triggered