Actual Engraving not Matching Lightburn Preview

Hi,

I’m very new to all of this. I just got my laser cutter a week or so ago, and have started using it. Looking over these forums, there is so much to learn… Anyway, in the midst of slowly taking everything in, I’m struggling with trying to understand why the preview of a cut I see in Lightburn, even at very, very close zoom in, looks different from what my machine actually prints.

For example, I have a series of eight boxes all joined together to create a grid. I created the SVG in Inkscape, drew one box, duplicated it, and then aligned them together. I used Inkscape to align them. Then, I zoomed in on the drawing, once I imported the file in Lightburn, just to make sure things lined up. Even at super close levels, it all looked good.

When I go to engrave the image, a test I’ve repeated a few times now, the lines are consistently off (always off in the same spot, the same way - despite very careful, up close adjustments). Specifically, the boxes are not all the same height. And, it’s the same boxes every time that are not the same height. I’m wondering if someone here might be able to point me in the right direction to try to learn what I’m doing wrong. I’m happy to provide Lightburn files, if that’s helpful. Thanks! Joe

Welcome to the forum and to the amazing world of lasers.
You might want to look at the import/export settings in LightBurn and adjust your import settings. But why jump between programs at all? Is there a specific reason why you don’t use LB to design in? Even though the functions are relatively basic in LB, compared to a CAD program, I design faster and easier with LightBurn, and the functionality covers all my standard needs.
But if it “has to” be Inkscape, try uploading the project here, so we can take a look at it.

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I second Bernd, try to upload some screenshots of the project and the results. Then we can better judge it.

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Thanks, so much, for all the replies. As you both suggested, here is a photo of some of the pieces I tried cutting this morning:

After working on the images above, I spent quite some time adjusting the image in Lightburn, redrawing about half of it there. I also made a few adjustments to the drawing, hoping that maybe if it was simpler it wouldn’t have problems. The updated Lightburn file is below:

waldhouse.lbrn2 (30.3 KB)

And, here is a photo of that cut, which still had problems (note: I forgot to turn on my air assist):

If you turn on node editing and zoom in close, you will see that there are some problems. You have many nodes and lines that overlap or are not connected, it is not so good.
You need to construct/design in LB as simple as building with LEGO bricks, drawing simple shapes and combining and processing them with the built -in features of Lightburn.

Try to look at my quick imitation of your original and you can see a little what I mean.

waldhouse2.lbrn2 (44.3 KB)

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Hi Bernd,

Thanks for the reply. I went back and created something directly in Lightburn, as you suggested. I did a test with two, very basic shapes. As you can see from the picture, the circle, is lopsided, and it isn’t completely closed (I drew this circle two times, and it was drawn exactly the same way each time).

Still what you said about the lines makes sense. Thank you for creating a comparison for me to understand. That’s a pretty deep level of detail :exploding_head:. I suppose I’ll just need to get used that!

I have a question about this, if I may: It seems a lot of people use SVG editors for their graphics. Is it normal to run into these kinds of problems using an SVG program? Do most people build their projects directly in Lightburn? It still, honestly, seems a little strange to me that the squares that made up the window panes were different when I burned them. They were exact duplicates of each other when I made them in Inkscape. If problems like that are common, I certainly won’t be using an SVG editor again to create my images, if I can avoid it.

Thanks, again, for all your help.

Joe

I think there are many who use external programs to design and construct, and or import drawings. Normally there are no problems if the drawing is properly made. But I and quite a few others almost exclusively use LB for design and construction drawings, it feels more natural to me. I have worked with CAD programs before, also with Inkscape and after a normal learning process was also relatively fast and good at it.
I use LB because it can do everything I need, except dimensioning in drawings, but it is not a deal breaker for me. There have been so many good new tools every year…, and it continues.

It is more likely a mechanical problem when your circles are not round, then there is something wrong with the machine, if it was a global setting for tabs then all shapes in this layer would show them, they don’t.

No, as I said before, it is not normal that imported drawings cannot be used. There are often some details I change on imported svg or pdf drawings, but of course they can be used, as long as they comply with normal standards and are exported/imported correctly.

This indicates that you have mechanical issues. You don’t need to go on designing before you fix your mechanics. See here for tips:

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Hi Bernd,

Thanks for the reply. It sounds like I may need to contact the customer service for my laser cutter. Again, many thanks for your kind support.

Regards,

Joe

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Hi Melvin,

I just saw your reply. Thank you for pointing me in this direction. I’ll take a look at the Wiki, and see what I can do!

Kind regards,

Joe

Don’t take a look, study it. Pay particular attention to the part about mechanical adjustments.

Bookmark @misken 's website. It is a goldmine of All Machines Sculpfun.

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@misken called it. This isn’t LB or Inkscape, this is mechanical.

On the subject of where to design: I started out in Illustrator 20 someodd years ago. As I have gone away from Adobe, Inkscape is now my powerhouse vector designer. But for most of what I do on the laser, LB has it all. I think some of their tools are actually faster and easier to use than Inkscape.

Any time you export/import vectors there can be some foolery when they come back in. Each program will process things other than basic shapes differently, leaving you with mystery open paths, intersections, oddly grouped shapes, etc.

Thanks, everyone, for the feedback. I’ll definitely study that wiki page, paying attention to the mechanical adjustments. Makes sense, too, what all are saying about designing in Lightburn. I’ll focus on that for the time being. Thanks, again, for all the help and advice.

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After looking into things, and pouring over the Wiki in detail, I think I’ve found an issue; however, I’m not seeing how to adjust this on the Wiki (maybe I missed it somehow?). When I run the tilt test, the gantry “clicks” at regular intervals. When I manually run it back and forth, I can feel “blips” at those intervals, as if it’s somehow catching or skipping. Has anyone had any experience with this that might be able to point me in the right direction? I checked my belts; they’re both tight. I do notice, too, that when I run the tilt test, the gantry doesn’t always start moving down. Sometimes, it does, and sometimes I have to nudge it. Despite the clicks, the gantry descends at a steady predictable rate, much like the gantry in the tilt test video on the Diode Wiki.

This is mentioned in the Wiki, see the section of the adjustment of the wheels. Your wheels are too tight then. Start loosening them bit by bit until the ticking is gone. But then immediately stop, it should not get loose.

There is so many texts that’s challenging to find that single sentence :slight_smile:

Hi Melvin,

Thank you, so much, for your reply. It was apparently the wheels being too tight that were the problem! Everything looks much better now. Again, thanks!!!

I had a similar situation. Looked good in Lightburn but would not cut properly. Actually, in my case, most everything beyond the center point of the laser work area got jammed into the left-hand quadrants. It turned out to be the air hose was catching on the gantry. but only on certain prints depending on the what the print was being lasered. It drove me crazy for a while.
Maybe you have something like that affecting your gantry.