Does anybody know how to do the textured 3d laser engraving with the big lasers?
Hey Jessica!
This process is best achieved Tarkin (it has enough power, the ability to scale that power appropriately, and the correct software to interpret the file). You can find some more details on the wiki page for Tarkin, under the depth map section.
Here’s a video outlining the process as well- https://www.youtube.com/watch?v=O01POwqfMbQ
If you browse some of the related videos to that/do a quick search, you can find details on how to edit/create an image that will work for this process.
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When you say “textured 3D”, are you looking to give Fills a graphical texture, like burlap or brick or something, or a true 3D engraving where it’s cut with actual depth?
Either way, Tarkin is the laser to use. It’s more powerful, but more importantly, it can modulate the output at much high speed. HVDC-excited (Dorian) lists a 1millisecond response time. That is, every time the controller turns on the output that goes to the hardware that drives high voltage to the laser, it will take about 1 millisecond for the tube output to reach full power and when told to turn off it takes about a millisecond to fall back to 0. Tarkin (and Pearl) are almost 100x faster to turn on or off the beam output completely when commanded to do so.
The diameter of the focal point is about 0.2mm. In most cases that becomes the pixel size. At 300mm/sec, the head will cover 0.2mm in 0.6 milliseconds. And you’d get best response when the beam only takes like 10% of that to turn on, stays on for 80% of the width, then 10% of the width is used to turn off the beam. So even at 300mm/sec, that would demand a 0.06ms response time- and 300mm/sec is kind of slow. And 1000mm/sec is the machine raster limit. So, yeah- faster RF-CO2 laser like Tarkin, Pearl, or Blue is much much better.
Anyhow, I have done “textures” before. In the graphical arts world, a true “texture” is a graphics file of bricks or stone or whatever and the trick is they’re designed so the left and right edges, and top and bottom edges, line up seamlessly. So you can tile a small texture file indefinitely. You can find plenty with Google, but that often brings up results that aren’t actually a repeating texture. Or you can ask AI to make a repeating texture.
In LB, you would Import that graphics file and use Grid/Array to make it repeat as far as you want it to go. But it has to be merged into one image object, so you select all of them, and Edit→Create Bitmap does that. This will be an “Image” type layer. This does work, but it’s pretty dumb- Lightburn can slow down quite a bit trying to do anything because the tiled image can become huge. You’d think it would be able take a 1MB template image and repeat it in software- nope, you have to take a 1MB file tiled 4x3 and converted into a new bitmap that will be 12MB long. The project file will be huge.
Then you’d take bold text or whatever you want to be this neato “Textured Fill”. Assign it the same layer number as the texture, but the type will be “Line” (not actually Fill type).
Then select both the tiled Image and Line content, and the “Tools→Apply Mask To Image”. You will send the masked Image layer to the laser. You don’t have to use the original Line at all, but you might send the lines too to add emphasis. Just with higher speed and/or reduced power so it will only mark the lines, not cut through with them.
But, to do 3D graphics, that’s something else entirely. First, you need a graphic in a “Depth Map” format- which is actually just any grayscale image in any graphical format (bmp, png, jpg, gif, tif, etc) but it was composed with the idea that black=deepest and white=shallowest rather than, like, a photo.
Then you need to set the graphics layer to “grayscale”. NOT any of the dithering modes. Depth typically needs a lot of power run slowly. Or full power, raster at kinda high speeds, but reduce the Line Interval to overlap the lines a lot as it goes. The beam may be 0.2mm wide at the focal point, but you use 0.02mm as the Line Interval and each point will be covered by some part of 10x different passes across it, thus 10x deeper. This is about the same depth and same runtime as 0.1mm Line Interval at 1/5th the speed. But the small-LI, many-passes version (either way, use 100% Power for sure) will tend to be smoother and render slightly smaller features.
Making a Depth Map is its own art form. AI can help.
Funny fact- say someone gave you a Depth Map that doesn’t go all the way to 0xff black anywhere (rare, but I’ve seen it)- let’s say it only goes from 0x00 white to 0x1f (only halfway to full black), then you will never be able to get the laser to fire at full power. If you set the Layer settings to 100% power, it will only output from 0% to 50% power to the laser even though you’re running super slow or using a small Line Interval so it overlaps like 10x lines as it goes.
In that case, you want to Normalize such an image with Gimp, Photoshop, etc so it actually ranges to 0xff black so the laser will turn on fully.
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Awesome, thank you! I will check out the video. I have used this laser before but it’s been a while. Would someone be able to refresh my memory on Tarkin in person or would I most likely have to take the class again? I took the class in person over a year but it didn’t cover everything and im looking to just learn this one skill on the lasers in particular.