Inventables Community Forum

I got a new laser (Opt Laser set up)

Just ordered the OPT xCarve kit, can’t wait.

Do I need to modify the firmware or factory newest firmware will work for PWM engraving?

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You have two choices for laser enabled grbl versions (three if you want to use the older Jtech version).

I modified Inventables 1.0c to be laser enabled and you can get it here.

The other option is the latest official grbl release 1.1f which is available in the Inventables download area.

Most of the people that use my version do so because my version does not change the way any of the G-code operations are performed and because it can run at a higher feed rate than 1.1f which becomes an issue with higher powered lasers (> 4 watts).

Some prefer the “official” release but it has some “safety features” built in which modifies how some of the G-code commands work when using the laser mode. Several of the GUI senders have been modified to work well with 1.1f.

Some people have issues with the way that 1.1f handles the laser.

Either solution will work on the Arduino/gShield and the X-controller using the PWM feature.


Laserburn works the best i have found for my 6w laser from opt lasers and inkscape comes with a jtech gcode converter.

I’ve been following Lightburn’s blog and there’s some feverish activity going on, both in features and fixes. It’s a very ambitious project. I have a feeling this will be my laser software choice too.

Yes sorry my bad, stupid iPhone and me not checking it.
What are you trying to achieve with the laser?
Maybe I am missing out on something else my laser can do, it seems to cut and engrave very well with lightburn.

M4 only? Interesting.

Let’s keep this thread Opt Laser specific. I asked on this thread.

Hi Anthony I’ve some hard times trying to configure easel with OptLasers, and decided to try the lightburn. Do you have the screenshot with the initial parameters for it to work?

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I purchased the OptLasers PLH-3D-6W 6 watt laser a few months ago. When I initially hooked it up, I had it wired to the analog spindle output, but after reading this thread, I switched it over to the TTL output. It runs so much better now, and I have much better control of the laser wattage output for grayscale and full burns.

One thing that I have also done though is to use a IOT Relay to power my dewalt DW611 and shop vac for router use.

This is connected to the Spindle Analog output, while the laser connects to the Spindle TTL.

I built macros inside UGS to switch between laser mode (GRBL 1.1f) and spindle mode, and have the machine auto home and then reset zero for either laser or spindle use to the worksurface 0,0.

It works very well, and is simple to switch between laser or spindle usage.

When running in laser mode though, I end up having to disconnect my IOT Relay, because I end up getting EMF bounce back causing the xcarve to disconnect from my computer during periods of fast laser switching.

Would using a shielded pair for the IOT relay help with the disconnect issue, or should I just continue to disconnect the IOT Relay while using laser mode?

Also, is there a simple way to tap into the 24V power supply in the X Controller for powering the laser? I use a DW611, which is self powered through the IOT relay, so I’m barely using any of the available wattage for the 24V supply inside.

I’d love to be able to tap into it, but I also don’t want to modify the case of the x controller unless absolutely necessary.


I’ve finished the assembly of my new XCarve and with it the installation os my PLH3D. It’s almost all new for me, but at some point I think I’m missing something.

The Xcarve is working fine with the Dewalt Spindle, there are just some minor adjusts in the belts and squaring it, but with the laser area things are a little more difficulty.

My Setup:

XController PWM (+/gnd), connected to both the IOT relay and to the laser Analog (+/gnd).
From relay I have an output in 127V to the 12V power supply wich send 12V (+/-) to the Laser.
I’m runninf GRBL ver. 1.1f on XController.

Easel try:

Go to advanced settings and change the following:
Draw anything, and send to carve, the fan turn on when I click at the turn on spindle and when I click carve it start moving but no laser at all.

Tried this about 5 times, even in two different computers and nothing.

Reading many of the materials in Xcarve forum, I’ve seen the LightBurn Software as an option, but downloaded it, installed and set as a GRBL controller, with an 1000mm x 1000mm area and go to the working area. Different from the easel, it doesn’t find the XController and all the time say it’s disconnected. Tried on a second computer and the same error.

I usuaaly don’t give up easily, but I’ve read many forums and lots of youtube videos, much of them have different setups, with and older XController or without the IOT relay but couldn’t find an answer. I’ve asked twice in the inventables forum how to setup for some guys who post many things, but no answer.

So i’ve decided to come here and ask for some help. The only difference from your setup instruction is the iot relay, wich I don’t think is the problem once the fan runs when it should.

Any idea?

Thanks a lot!

I don’t recommend grbl version 1.1f for laser users due to the changes it makes in the way G-code commands work. I prefer this version if you don’t require spindle speed and feed rate overrides., but you can get 1.1f working if you read this document and follow the changes.

For my version of grbl use these settings for laser mode:
$30=255. (rpm max) ************* This value can be anything for grbl 1.1f
$31=0. (rpm min)
$32=1 (laser mode, bool)

Here is a good way to handle spindle/laser selection. Change D11 to PWM output for the X-controller and use GND beside it for the Arduino ground.


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LarryM, thank you so much for your help. Initially I would try and learn well it with the stock firmware, after having total control and understand all this them it would be time for more deeper changes.

So the first step will be making it work in the 1.1f version and trying to use it and see what are this version limitations and see if my working flux is impacted by any limitations.

Looking at the document you recomend for making the 1.1f work with laser, I saw the changes I’ve done in $30, $31 e $32, and those I already know where to do inside Easel (machine>advanced>machine inspector) but I don’t know where to insert those commands like G, S or M. Is it in the same place? Or is there a Command line mode somewhere else?

I don’t have the machine here, but will try it tomorrow in the morning.

Thank you again, for your time and patience.

I noticed that you had $30 and $31 reversed. Have you tried fixing that yet?

I will review it, but maybe I just typed wrong here, I’ve done it a few times, even in two computers following the guides from here… Anyway thanks for your attention to this detail…

When you say it doesn’t find the XController, have you actually selected a COM port? With GRBL, LightBurn doesn’t auto-select because every Arduino has the same USB ID’s, so you have to manually pick. Once you’ve done that it should work fine.

I just tried Lightburn for the first time tonight and ended up with the same issue.

If you look at the devices box, it will be there. Change it from (auto) to the correct com port for your setup and it should connect immediately.

Make sure you don’t have any other control software running such as UGS or Easel.

i would like to order the Optlasers PLH 3D-6W-XF to upgrade my cnc Router
i need this laser head for marking on anodized aluminum Drones parts
please any help , if this laser can do the job with good results .did anybody tried to engrave on anodized aluminum with this laser head

Yes. This laser will mark great on aluminum, especially anodized. If the aluminum is raw or clear anodized when marking, you will need to use a marking mask spray, but colored anodized aluminum works great.

thank you so for your help

Helllo Samerson did you still need some help with your laser if you do happy to help