I am still new to LB so excuse me if something similar has been posted before. I looked but didn’t see much on this.
I tried to create a simple inlay using standard text. And only part of seems to fit. Here’s what’s happening.
I used a large block style typeface Arial Black I think. I made the first cutout (inlay) in one type of wood, negative (I think) kerf. Then I made another cut out of the same text, positive kerf (base) from a different wood.
When I fit the inlay into the base, it’s a tight fit, but I could do it. But the inside of the letters, like the cutout on the inside of an “A” or “D”, are just way too small, very loose fit.
Which makes sense. If I do just a plain circle, they fit fine (like the letters), So, in a sense, the inside of the letter, is like the circle I just made, inside a letter. It should have a different kerf setting. Think, cutout inside a cutout, you should have different kerf settings. (when you use a larger kerf to make the letters a bit larger, it makes the hole larger too)
So, is there a way around that? Other than using a drawing file (and not text), or making 3 different cuttings. Seems a waste to cut out an entire inlay, just to get those couple small pieces.
I don’t have the software yet, my gerbil is in the mail. I’m starting be concerned with the cnc capabilities based on what I’ve been reading.
Anyway, I do inlays and software these days doesn’t do kerf right. I recommend that you cut the letters with no kerf, just make them the size that they would be if they had the right kerf. Then you can either do the same for the outer part, or you could try using kerf on that one if it doesn’t have inner holes like the letters. do.
Do you have any problem editing the cnc it generates? I’m worried that it won’t work for me. Can you insert lines during the edit process?
If you think of the laser as a very small CNC cutter, it all makes sense: one side of the cut is the shape you want, the other side is waste material. You generally can’t get two usable pieces from a single cut.
The trick is to figure out which pieces need the same kerf setting, extract those shapes from the overall design, rearrange them to use the least material, then cut them together.
The complete layout in the upper left generates the frame with no kerf adjustment, so its interior pieces become too-small scrap. The separate pieces along the bottom all have +0.15 mm (outward) kerf adjustment for a snug fit:
Obviously, I didn’t optimize the layout of those shapes to reduce the amount of chipboard I used. LightBurn can pass the shapes to an external nesting tool to automate the task.
I did it the other way for some snowflake coasters, with the frame getting outward compensation and the interior pieces cut at the nominal size:
The white acrylic on the left had no compensation, so the pieces fit loosely. The one on the right got +0.1 mm outward kerf compensation and the same-size wood pieces fit tightly.
There’s no way around cutting those additional shapes, but you can more-or-less easily minimize the additional material by rearranging them.
One gotcha: the LightBurn design must have separate shapes. If you’re making a jigsaw puzzle with single cutlines between the pieces, those pieces are not separate shapes that you can extract for kerf adjustment. You may need some duplication or outright trickery to create the shapes you need from the pattern you have.
Thanks for that.
I’ve been messing with it a good bit. One problem I had, is my machine was not quite as square as I thought. Took a couple of days, but I think I finally have it as close as it’s going to get.
And the cut out I was working on, was the Alabama Tide logo, the stylized “A”.
The file I had, had each line as it’s own. So it’s like 4 “objects”.
What I “should” have been doing (I think), is treating a couple of those objects as one. Like the inside “A” is one object, the thinner, lighter colored outline around the “A” is another object.
Now the machine is pretty square, I’ll try it again. But what I was doing, was pretty small, maybe too small for this. (wine bottle stoppers).
I’ll let you know if it’s any better. I know, bigger would be easier, but small like this, it’s all so fragile. I think one issue, was just the part burning up. Thinner wood etc… would help that. But not sure if it’s all worth it for these.
Thanks for the suggestion on kerf, I may have to try that.
I’m not sure if you can edit the code or not. I’ve only been using the trial package to test a few things (upgraded today yay!).
If not directly, I’m pretty sure you can save or export the code, and use your favorite editor on it.
From what I’ve seen, graphic artists achieve the look with no regard for anything else. The digital file looks good, but trying to use the geometry for another purpose always has hidden pitfalls.
For relatively simple shapes like that logo, treating it as a layout guide may be more successful. Basically, you hand-lay LightBurn’s native paths and objects to match the appearance: the result looks (almost perfectly) identical, but the shapes match what the laser needs.
A trivial example to fit an oval container:
Fitting curves to a hand-drawn pattern:
A marquetry faceplant due to my misunderstanding of how the auto-trace routine works:
Stipulated: my artistic ability rounds off to zero.
