NEJE-like Laser as CNC upgrade

[FelixH]

Thanks again @radiomodell . It's a lot of info right now, I shall look at in with more detail once my laser arrives. I am still on RRF 2, so I will have to adapt. I also ordered the components to build the breakout board. Just in case...

[sh12]

@radiomodell , not to hijack this thread but I am running into the exact same thing. I have the NEJE laser module but cannot get it to be controlled via pwm. It is always at full power. Can you tell me exactly how you have it wired?
I have 12v supply going to 12v, and Gnd pins. Then I have the duex fan6 pwn pin and fan6 gnd pin going to the laser pwm and temperature (or gnd) pins.

Looks like you may be able to walk me through this if you're willing.

[droftarts]

@radiomodell said in NEJE-like Laser as CNC upgrade:

M452 C"exp.heater6" R500 S1 Q20000 ; laser uses heater3 pin, PWM frequency 100Hz;

@radiomodell @FelixH @sh12 Please note 'Q' parameter is incorrect, it should be 'F' for PWM frequency. The example in the Gcode dictionary for M452 was incorrect, but has now been fixed, thanks to @Royassas (see https://forum.duet3d.com/post/168234)

So @radiomodell, you're probably using a PWM frequency of 500Hz, which is the default!

Ian

[radiomodell]

@droftarts said in NEJE-like Laser as CNC upgrade:

So @radiomodell, you're probably using a PWM frequency of 500Hz, which is the default!

Thanks a lot for the hint! Laser worked fine til now. I will correct M452 command before next use.

[radiomodell]

@sh12 As far as I know, expansion board pins are at 5V level. please check your documentation and use a level shifter to connet laser PWM-pin with 3.3 volt.

When using Fan6-PWM Duex output pin following command should do initialization: M452 C"duex.fan6" R500 S1 F20000 . R- parameter sets 100% value of S-Parameter in M3 command. M3 S500 is 100%, M3 S250 is 50%. Dependent on source of G-code i adjust R-Parameter.

My PWM signal input is connected to Heater6 pin on expansion connector of my Duet2. Thus I use this command M452 C"exp.heater6" R500 S1 F20000.

[sh12]

@radiomodell Thanks,
Even though the specs on the laser says the pwm will work on 3.3 to 12v, I will connect it to a heater pin today and change the Q to F.

[radiomodell]

@sh12 PWM Vpp is 3,3V Check the link and scroll down: http://nejetool.com/module_20w.html

[sh12]

@radiomodell said in NEJE-like Laser as CNC upgrade:

@sh12 PWM Vpp is 3,3V Check the link and scroll down: http://nejetool.com/module_20w.html

Thanks @radiomodell . If you go down a little further in the notes it says this:
Is the power adjustable: PWM can be adjusted, PWM: 50KHz-20KHz / 3.3V-12V
I had even contacted the seller to verify and he assured me that it was from 3.3 to 12.

Anyway I duplicated your setup and YAY, it is working! So thanks again. Now to focus it and figure correct speed.
Do you know if the firmware was ever updated to allow the laser to be on without the G1 command first for focusing purposes? I saw a thread where David was talking about that.

[radiomodell]

@sh12 Firmware fires laser only when moving by G-command. Thus for focus operation I terminate Laser Mode (M452 C"nil") and put a PWM signal manually. (M950... etc ).

M452 C"nil"                   ; Laser vom automatischen Einschalten bei Bewegung trennen
M950 P3 C"exp.heater6" R255 F20000 ; Laserleistung auf P3 umschalten
M42 P0 S255                   ; Laserpower einschalten
G04 P1000                     ; Pause, bis Laserpower stabilisiert ist
M42 P3 S0.01                  ; Laser mit 1% Leistung einschalten

Please be careful! Laser i continuously on and burning on one point!

After focusing laser I use following commands to switch back to normal laser mode:

M42  P3 S0                  ; Laser aus
G04 P500                    ; kurze Pause
M42 P0 S0                   ; Laserpower aus
M950 P3 C"nil" 
M452 C"exp.heater6" R255 S1 F20000  ; 

[sh12]

I was referring to this thread
https://forum.duet3d.com/topic/15826/behavior-of-m3-command-im-laser-mode-m452
where @dc42 said there was a request to have a laser mode available for focus. Was just wondering if it ever went anywhere.
Oh well, at least I have it working now. That was the major hurdle.

[g0rg]

Hello and sorry for editing this topic but I'd like to ask to @FelixH or @sh12 or some kind friends here to help me with the same setup (workbee, duet2 wifi, neje 20w). I can't get rid of it knowing how to wire and how to change the right settings/macros or flashing to RRF3 or making the special inverter board.
Maybe on my personnal mail box or a new topic ?
what's the best way ?
Sorry but i come from Grbl world

[FelixH]

@g0rg to be honest, I have been incredible busy the last few months to even considering doing the upgrade... last thing I did was to design a small PCB to connect the laser. It is more or less the same as described in the Duet Wiki, but for through hole components. I shall be able to get into it in a couple of weeks. My setup is still the same: Workbee with Duet, running the latest Ooznest version of the firmware. I guess it is a standard RRF2, but I don‘t know. I am guessing the folks at Ooznest only changed the Web Interface to make it more CNC-friendly, which makes me think if I should update to RRF3 or not.

[Phaedrux]

@FelixH from what I gather Oozenest is working on a RRF3 update.

[FelixH]

@Phaedrux cool! I‘m looking forward to it. With some luck they will incorporate the autosquare feature, if I’m not mistaken it should be easier with RRF3

[dc42]

@bearer said in NEJE-like Laser as CNC upgrade:

a little OT, but M997 ignores M505 or is it just me?

Yes, M997 always looks in /sys, and uploads of .bin and .uf2 files always go into /sys.

[g0rg]

@FelixH I already setup my workbee with autosquare on homing by adding a second switch on Y axis.

As a test purpose i updated a second duet wifi board with RRF3 and i still try to understand how to wire my laser and still try to understand how to spell the fan port i would like to use maybe a help from @sh12

[dc42]

The recommended way to drive an active-high laser PWM input is to use a 74HCT02 to invert one of the PWM signals on the expansion connector and gate it with +3.3V. However, if your Duet 2 is out of warranty, you could tap into one of the heater mosfet gate pins instead, if you are not using all three heater outputs.

[FelixH]

Hi all again,

I am today trying to wire the laser but, before I do I have a doubt regarding the following diagram:

https://duet3d.dozuki.com/Wiki/Laser_PWM_control

in this diagram, what is exactly HEATER_3 ?? It is the heated bed, extruder 1 or extruder 2 ?? Also, I am assuming is the "negative" pin of said heater, right?

[PopstarPorcupine]

I installed a similar NEJE laser ("30W" with ~7.5W optical) and got it working easier than expected after reading all the forum posts. Maybe having the Duex5 was key as it just plugs into +/- of servo plug. The TTL Board that comes with unit has 3 modes when you push the pwr button: Off, Manual PWM via board buttons, and PWM-input-controlled.

I have been using Lightburn for Marlin with "inline" selected for "Laser Control Commands" to make gcode.

;Laser T6 Tool Definition
M307 H6 A-1 C-1 D-1; disable heater6 channel
M563 P6 D0 X3 ; Tool 6 Laser on U axis no heater or fan (change if on X axis)

Tpre setup:
M452 P6 R255 F10000 S1 I0 ; switch to laser mode Heater 6 PWM/servo to control the laser
M42 P6 S0 ; Ensure Laser Off
TFree setup:
M451; Go back to FFF 3D print Mode

[FelixH]

@PopstarPorcupine thanks a lot for your info. I prepared the mentioned board and I used the heated-bed PWM port. I still have to bring it on-line, however. Not tried it yet. I've been really busy preparing a new electronics box for my Workbee with the Duet, the SuperPID and everything else... I think your snippets will be much uselfull. Thanks a lot again.

EDIT: what about the Lightburn software? is it worth it? There are not many options for for mac users, Lightburn beign one of the few I found...