Setting up dual laser support with RD6445G controller


Last year I built my own laser cutter based on a RECI W1 tube and an RD6445G controller. It functions very nice but now I want to add a second laser (actually a diode laser to get finer control for engraving jobs).
I enabled the ‘dual laser’ support and ‘laser 2’ via the Machine settings option in LightBurn. Wrote the settings to the RD6445G, resetted the controller, restarted Lightburn. After doing that, I would expect to get the ‘Laser 1’ and ‘Laser 2’ option in the cut window. But it does not show up.

Any suggestions what I am doing wrong?

Go to Device Settings and enable “Enable Laser 2 Controls” and “Enable Laser 2 Offset”. Once you do this the cut settings will show the option for the second laser.

Thank you berainlb. I can now see the options in the cut window!


Please post photo’s of your co2/led hybrid…


I concur with @jkwilborn. Exotics are by definition interesting and deserve some visuals.

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It is my intention to combine my CO2 laser with a diode laser (5-7W) to get better control over engraving jobs. My 75W CO2 laser (that fires at a minimum power setting of 6%), is a bit too coarse when trying to engrave fine patterns.

So now that I know that dual laser setup is supported by Lightburn, I will order a diode laser and add it to my laser cutter setup.

Anyone a suggestion of a good quality diode laser head? I already came along LU2-4-SF from Ortur for example.

This is a picture of my current setup…

My second laser was a Neje 30 watt. Still have it and it still works… Of course I use the co2 almost exclusively.

A photo of the head assembly would be nice…

Very nice machine…

Good luck


As soon as I have a diode laser mounted into my machine, I will post a picture. Give me some time :slightly_smiling_face:

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I just ordered a N40640 from Neje. As soon as it arrives I will have a look how I can mount it on my machine + how to connect it to the RD6445G. I hope the interface of the laser diode will be compatible with the RD6445G (PWM/TTL). If not, I will have to dig a bit deeper in the electronics. If anyone has already experience in hooking up a diode laser head to a CO2 controller, feel free to share your experience!

I would think it would be ‘extra simple’… Your only ‘control’ options are supply voltage and pwm control. I would leave it powered up as long as the machine was running a job… control it with the pwm. At least till I figured out what it was doing…

Should be able to run LPWM2 directly to the laser pwm pin… and of course a common ground.

I don’t know how/if you can use LOn-2 or if it would be even needed with an led laser. I know this is connected to the L input of the lps, sort of a ‘supply’ enable and is active low (configurable). Never looked at this on a scope so see how it actually worked during a run. It might take external circuitry to control the led laser supply with this output…???

I have one of Neje 30 watt models.



An intermediate update : I received the Neje N40630 diode laser in the meantime and installed it on my laser cutter. Hooked up the L-PWM and GND wires from the RD6445G controller to the diode laser input (take care : RD6445G outputs 24v level signals, N40630 accepts up to 12V signal level, so I inserted a voltage limiter (zener diode based).
To make a long story short : the diode laser works! Only artefact that is remaining, is the fact that the diode laser stays faintly on during idle moves. This probably has to do with pre-ignition (that is needed for CO2 lasers). Will investigate this further. Once finished I will share with you in some more detail the different steps I took.

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I think you can invert the pwm if that would simplify voltage translation. Of course you’d have to set it back for normal operation.

Have you created a configuration for it?

Kind of bummed… no picture :sob:

I interfaced an ‘active’ low from the Ruida to the input of an Arduino using a blocking diode.

It might be worth a configuration change, since it’s so easy to do with Lightburn

I haven’t fiddled with the pre-ignition, but thought it was basically used for RF excited lasers.


Hello again! A further update after spending (a little) time this weekend on my laser cutter:

In order to suppress the diode laser activation during idle moves, I combined the L-On and L-PWM signals. To be specific, I connected the L-On signal of the RD6445G to a NPN transistor that blanks out the L-PWM signal when the laser is off (when doing an idle move). This works perfectly :grin:

As soon as I find some more time, I will put together all the information in a document and post it on this forum (with pictures :smiley_cat: ).

ToDo : mechanical offset calibration (setting in Lightburn), final construction and mounting of fixation brackets for the diode laser, tidying up the electronics components and cabling.

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