How to setup a new diode laser unit 15w

I’m new to laser units but have a few years of experience with a simple 3018 cnc. I got the creality 10W laser for my 3D printer and that worked great with engraving and basic cutting. The downside was that I couldn’t use my 3D printer when the laser was installed and visa-versa. So I sold the 10W creality laser and bought a 15W vevor laser with adjustable focus. (XTS15W blue laser) Installed everything according to the instructions but the end result is that engraving works but basic cutting is so much worse than the Creality 10W laser that I had. The cable that came with the laser module was also wrong, the power and PWM were mixed up. I corrected that before I started.

Is there anything I need to change in the grbl settings except for the obvious $32=1 and the $30=1000 and the S value in Lightburn = 1000 setting? I have the feeling that the laser isn’t performing at its maximum capacity or I have bought the wrong product.

Any advice is highly appreciated, did I overlook something?

The manufacturers of premium laser engravers tended to specify optical power output when rating a Laser Module. The ‘second tier’ manufacturers offered Power Consumption of their laser as their rating.

The Creality was likely a full 10W optical output device. If the Vevor is 15W on the input (the power consumption side) then you’re looking at about 2-4W on the optical output. I’d apply 4:1 as a solid assumption about the ratio between Consumed Power and Delivered Optical Power.

The first question I would ask is, are there two or three wires from the controller to the laser diode module? Second question, is the power supply ‘brick’ for the laser engraver controller a 12V or 24V device? Followed by, do you have a Digital Volt Meter that is also equipped with a 10 Amp Scale?

At full power (S=1000) the laser engrave head will draw maximum power and it will be 100% duty cycle so there won’t be any weird signals to throw the ammeter off.
Measuring the current draw will show you that you have either 15W Consumption / 24V supply = 0.625 Amps draw, or 60W Consumption / 24V = 2.5 Amps draw.

If the power supply says 24VDC at 2 Amps, you probably don’t even need to consider the meter, at 3 or 4 Amps you should be fine.

Hi John, thanks for your reply. According to their website, the creality laser was a 10W output and the Vevor 15 W output. There are 3 wires from the control board to the laser. The control board is powered with a 24 volt power supply. I don’t have a digital volt meter with a 10 amp scale, unfortunately.

Are you saying that my new Vevor 15W (output) is what it is and turns out to be a lot worse in cutting than the 10W reality that I had? Anything else I could check to find out?

Would this laser be a better one that will give me the opportunity to cut 5 mm (black) acrylic? With the Vevor, if this is what it is) I can forget that.

Having a 24V supply is a good sign.

If the power supply is rated for 3-4 Amps you have enough power available for 10W optical output.

I seem to have reversed some of my numbers - I fixed those and changed the voltage from 12 to 24V.

24 volts output, 4 A (96 W) and my vevor laser is 15W output. Laser is 15000 mw, wavelength 450 nm blue, 12V DC, PWM/TTL , laser-interface 2 pins.

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I have a Laser Tree 80 Watt on a DIY using a 12 V 4 Amp supply and with LaserGRBL it works fine. However with Lightburn, even though the laser lights, it does not burn the material.

These settings control how the software commands power from the laser.

@Roger12266 Please confirm $30 and S-Value Max are set equally in LightBurn.

yep, both are set to 1000…

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So I went from 10W output to 15W output and now I have 20% power with my 15W compared to the 10W I used to have. I feel like I bought a crappy laser now… All I want to do is be able to cut 5 mm black acrylic and engrave. Any suggestions for a laser that will be able to do that?

I’ve seen the relationship with $30 and S-Value Max…

I do not see anything about $31… is that not part of the equation of how the pwm generation is computed within Lightburn?

Unfortunately, I don’t have my grbl machine available for checking what happens to the pwm with a $31 value set to something like 500…

Figured you could probably enlighten me on how that value is used…

I use digital hand meters quite frequently and found that current, on a square wave input, will show it’s relative percentage of the peak value…

If it’s drawing 200ma, the meter would read 100mA with a 50% pwm… pretty much like an analog… nice thing about square wave control…

This is more common than it working out of the box… Unless you buy it from the people who made the machine… this is quite common…

That laser will never cut acrylic… I can’t find much on manufacturing of acrylic as far as what makes it a color… As far as my education goes, it’s an additive… but whatever…

Acrylic itself doesn’t absorb visible light, so the heating is done by exciting whatever the black substance is and that heat melts the acrylic…

The best laser for acrylic is a co2… the frequency of it’s emissions are considered about perfect for acrylic. Many claim that’s the co2 claim to fame is how effective it cuts acrylic.

I’d suggest doing a ramp test to ensure the new laser is properly focused… This is probably the number one failure using lasers, improper focus…

I’d check a new lasers focus before ever trying to use it…

I’d also expect better performance with the 15W over the 10W… about 50% better :wink:

Good luck


I have successfully cut 3mm black acrylic on numerous occasions with my diode laser, never tried anything thicker though :+1:

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I have set all of the GRBL parameters and the Lightburn parameters to match but, although my laser lights up, it still has no effect on the material to be engraved.

I have the GRBL parameters set properly and have matched them to the Lightburn parameters but the laser, although it gives off light, has no effect on the material to be engraved.

What I’m trying to say is you are not cutting the acrylic from the laser… it heats whatever is black, that heat melts the acrylic … if this were not the case, clear or any color would work.

Commonly referred to as the indirect method…


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Thanks for your reply Jack. I have seen video’s about cutting black acrylic and some say it is not a problem, other say it is. I will change the $31 value and see what will happen. I’ll let you know.

There are many questions about different kinds of diode lasers. I have ordered the latest 10W model for the 3018 from and I will compare the Lasertree with the Vevor model with different materials, that should be interesting.

BTW, I did do several tests to focus the Vevor laser, it hardly cuts but it does a good job with engraving at lower settings. I will compare the 3018 Vevor with the 3018 Lasertree model and I’m very curious what that will do.

Thanks for your help and suggetions!

I agree with you there but direct or indirect, as long as it does the job and gives me a clean cut, I’m happy.

Thanks for the explanation Jack, that makes perfect sense :+1:

It does and that’s why some colours work and others don’t.

I have tried with different $31 settings, from a value of 100 up to 1000 but it didn’t change the results unfortunately.

Can’t argue with success… agree completely. I’ve seen some pretty nice artwork with clear acrylic using tempera paint as the indirect component.

$31 question piqued my curiosity… I found this hunting around… seems to explain the $31 variable…

Anyway I’m content… next time I get the grbl machine out, I’ll hang a scope off it and see what happens…