Kerf Offset test: with built-in vernier scale for accuracy, no tools required!

The rectangular beam was one of the main reasons why I changed the laser head for another one with a square beam.
For projects that require more precision it makes a significant difference!

Which one is this? Didn’t know anyone made a square emitter…

Even being square, the hypotenuse distance is different from purely X and Y direction size…

If it’s not round, you end up with the same issue, don’t you?


Anything other than round is not optimal, but there is a huge difference if you have a 1:3 ratio elongated beam or a beam with 1:1 …….

This is the one with rectangular beam:

And this is a LT 40W (power consuption) fixed focus with a square beam that I am using currently:

As far as I know the construction of this one consists of two rectangular laser LEDs mounted side by side.
But I never dared to take it apart to check the veracity of the information. :smile:

Yes, of course, but as mentioned:

And as far as I know, there is no round laser LED. (at least that I can buy without selling an organ) :innocent: :smile:

That’s exactly it for a diode - the beam can be rectangular. I’d assumed that I would either take an average or the largest kerf as my kerf setting, but your suggestion of different kerf settings for different x and y layers while sounding complicated could be an excellent solution for slots / tabs / “dove tails” - which for most of what I’ve done is where I’d want the higher tolerances.

But, bringing it back to the topic at hand, I think that I will build a kerf corrected version of this where I can just cut out the squares in any new material to get a kerf measurement. The nature of using squares is that I can check the X and Y kerfs separately - and make an informed decision.

Again, thank you for the idea!

I apologize if I didn’t understand your intention correctly due to my poor English, but…
Why, instead of building a corrected version, don’t you simply rotate the drawing 90º, identify it as “vertical kerf” for example and run the job? :thinking: :wink:

I’m looking to create a reusable tool - the “corrected” version won’t contribute to the kerf being measured, so using it with any material would be accurate. I can cut the caliper part once, and then just cut a set of squares to measure the result of a new material (or I suppose cut type). Note that I either need to increase the number of squares, or lower the denominator from 20 to 18 - as there would be two less cuts contributing to the kerf calculation…

This is square?

I believe there is a M2 value called beam quality that takes a lot of this into account.


This is my 20W (quad diode) output at focus distance onto painted aluminum. 1mm square with a pulsed dot at the center. The “dot” measured approx .09mm x .40mm

1 Like

Well, it seemed to me that I hadn’t correctly understood your intention. :wink: :+1:

It’s a blurred square. :blush:
It is about 2m (not mm) away from the focus point. :smile:
So for me, who don’t need micrometric precision, it’s a perfect square at the focus point with the dimension (if I remember correctly) 0.02mm :innocent:
Or not, because I see poorly and what is supposed to be a spot I see as a stain. :joy:

I would say this would be the result I would get if I did the same with the previous laser.

I think General Motors calls that a “squircle”. (Reference C8 Corvette steering wheel publicity.)

Of course, in their infinite wisdom, they also decided to call the front storage compartment a “frunk”, so “squircle” probably isn’t a great term.