I would like to suggest a setting to compensate for non-square laser “dots”. It would be specifically useful for powerful diode lasers that combine the output of several diode into one unfortunately not square laser dot.
Users would have to figure out the orientation of the dot (dimension in x-axis and y-axis) and the software could use that for e.g. a “modified kerf” setting (i.e. non-square).
When implemented properly, a laser with non-square focus would behave identical to one with square focus.
thank you, parsec, I have discovered an open feature request for independent X-kerf and Y-kerf there and upvoted it. Imho this setting would be a major benefit over LaserGRBL. Given that LaserGRBL is getting better, Lightburn might benefit from new feautures that set it apart from the competition.
Though not a generalized solution like you’re looking for, “Dot Width Correction” which is available on Image layers may work to address one aspect of dot asymmetry.
In any case, worth exploring if you work with images.
We rarely work with that detail of control. It is usually set so it is more than enough for X and just enough for Y. In other words, cut through no matter what. Too much is harmless, not enough is scrap.
in my case it would significantly reduce the time to do precision model building. With the 10 W diode I never had to make any adjustments and hat tight fits in both X and Y directions and consequentially also in any other orientation. The non-square 40 W diode no longer is that accurate (albeit a lot faster). An independent kerf adjustment would improve the accuracy of high power diode lasers for precision work
I agree with you. I’m missing this feature too. It took me a lot of time to find the right settings for my 20W diode laser to cut. It’s just a compromise with the current possibilities. In my opinion, you can only achieve optimal settings if you can adjust the spot separately in the x and y directions. This is particularly true for powerful diode lasers. Because the relatively large spots are responsible for larger deviations in the final dimension.
In the meantime you can turn all objects to 45 degrees. Then the kerf is the same for both directions, since it’s the diagonal.
There is a video about it, I think I put it at the end of this page: Specific guides - Diode Laser Wiki
This is like expecting quality and cheap at the same time.
All diode lasers have a rectangular beam pattern due to how the device is made. Precision depends on the beam size more than the X-Y ratio. I have seen images done by an $800 laser HEAD that are stunning in their detail. That is precision.
You cannot improve precision by getting an X/Y=1 ratio on a fat beam. You only get similar burns in both axis. By burning at 45 degrees as @misken suggested, you get the beam width of the diagonal. Less than Y but more than X. In other words, an average.
The tool linked by @parsec looks very interesting. But remember it cannot improve precision. It will only improve consistency between X and Y burn patterns. A fat dot is still a fat dot.
And yeah, I hate it when I turn the part over and see X has cut clean through, but Y looks like a dashed line.
while I agree in general, one should still strive to get the best out of the tools available.
If Lightburn can improve the accuracy by adding a mechanism to compensate for non-square (or oval) laser dots, then that would be a welcome and useful addition and also potentially an advantage over competing products (Lightburn is a business after all).
This depends on what you mean by “accuracy”. If you are talking about positioning accuracy, then Lightburn can help. In fact, it does have settings to improve positioning and repeatability. Precission is different. A ruler with 100 lines per inch has more precision than one with 32 lines per inch. And both can be equally accurate. No software can make the second one have higher precision than what it is physically capable of.
I feel we have a blending of terminology. Accuracy, precision, and repeatability are 2 independent concepts. Better accuracy and repeatability will not improve precision. And higher precision of the beam does not mean it will go where it is supposed to.
I am not aware of any competing products. Lightburn is lightyears ahead of the other laser control software packages. Yes, it can be improved. And it is, just look at the list of releases since it first appeared. I admit (reluctantly) that there could be something better out there, but it would be limited to a single machine manufacturer and cost thousands of dollars.
No, I am not on the Lightburn staff, and yes, I paid for my copy and upgrades.
I agree with this suggestion. I have a 60W Falcon 2 Pro laser and if you cut a small circular hole, it cuts an ellipse. If I cut a 1” square hole, the kerf is obviously different in the x and y axis. So I have to set my kerf as an average. For small holes, I can dial the laser back to 22W where the laser beam is closer to square.
For that kind of accuracy, I would try Increasing (decreasing?) the Yaxis dimension a tiny bit. Make one, measure it, and you have the needed difference. What I am saying is find a solution until Lightburn can no longer be improved. When you find a solution, share it. Don’t wait for a Feature Reques to become a Feature Added.
Thanks. I can figure out a work around by stretching x or y in LightBurn, but that is a boot strap approach. A software fix should not be that difficult to implement…
If it’s a rectangle, and only using x and y for directions, then you could come up a kerf correction, maybe.
However most of us let Lightburn use whatever direction it wants to move, meaning you’d have to handle a rectangular beam at every angle it goes through.
Think of going around a circle… the kerf will change as the cut direction or angle changes. This brings up many more questions.
Doesn’t sound like an easy modification of the software to me, but I don’t know what’s under the Lightburn hood – just my opinion.
In my opinion this is not the right approach to solve the problem. With my 22W laser, the effect hardly occurs at all when engraving. You can only see the difference when you cut it. You would then have to have 2 setups, once for engraving and once for cutting.
Even if the desired software solution does not deliver 100% results, it would be a great step forward in achieving better cutting results for for powerful lasers.
True. But I meant it to be a temporary work-around, not a solution.
Not sure what you mean here. I place the board, engrave, then cut without moving it. That would be two operations (layers), right?
If you are having a problem wi5h dimensional accuracy, maybe you can start a new thread and let the Forum collective try to help.
You only list one laser in your bio. Do you have a more powerful laser to test with?
Because of the smallest beam dimension still being too large, I only use the 40w setting for making cut-outs in 10mm bamboo cutting boards. I used the 20w setting last night to make a live hinge tabbed box (last minute birthday gift). That was done with no kerf setting or Yaxis correction.
