Curious how wavelength/frequency, focus, energy and other stuff can be tuned to laser etch super fine lines of desired depth? Real holograms use lasers right?
Minor update from me… inching closer to first engraving, implemented SVG Export, barely working. Fortunately, EstlCam is able to load many many arcs… EstlCam is able to generate G02/G03 arc based movements thanks to SVG being generated with arcs (PITA to code). So hopefully gcode size and engraving quality won’t suck, will see…
There is no “real holograms” (almost) 
But yes, they use laser’s.
Also for fiber laser engraving perfect distance between each arcs is 0.08-0.02 mm¹, maybe need to scale that project size to make distance’s equal to those ¹sizes.
I’m wondered how different communities have different access to the world knowledge’s…
If laser engraving community will have people with programming skills like this community, together we can evolve completely faster in such many different ways
Upd.
Also maybe it’s be useful, you can also change arc shape to give animation “smooth transition”
And here example how looks hatch 0.009 mm with different height, done with 30w fiber laser on stainless steel.
Update from me…
Short: Meh.
Long:
Simulation is better than reality. Can see the effect, but it’s too subtle for my liking. Was hoping for holographically enhanced Logo etching. Instead, have ended up with logos that look like they should be shaved, or waxed even…
Clear, 50% opaque, opaque sample :
Glossy black opaque acrylic came out best so far. Haven’t tried metal. Tried various lighting and lasers to maximize effect. Very light scratches are better than deeper gouges.
Lighting and camera need to be carefully aligned to have reflections off the arc be visible.
Extended original app to be able to load binary/text .STL files, and export SVGs with the front faces merged into an easy to select profile, so toolpath creation is easier.
Trying some other materials, with shallower engraving. Will end up with a .STL to .SVG converter if nothing else. Can export with or without arc scratches, so, can use for other scenarios beyond specular holograms…
Anyone manage to get specular hologram results they’re happy with?
Let me know if you’d like to try the modified app. If anyone’s interested I’ll spend more time cleaning up so it’s more stable/performant.
Can you try with a single LED instead of a bulb? Maybe your phone flashlight?
Oh I wanna see this work…
Is there any way to dial down the downforce of the diamond drag? So the scratches need to be just shallow enough to not really see but high enough to catch a hint of light. Sounds difficult.
What about a toolholder with a soft spring?
The drag knifes have an internal spring.
The diamond bit digs into the black acrylic too easily, trying again with bit in LR3 Pen mount instead of router, and loosening spring as much as possible… Cheers for the suggestions! Was planning to give up and move on to unfinishing another project, but you guys keep sharing ideas/suggestions…
Edit: LR3 Pen Mount is too short/high and doesn’t secure to my Core/Makita as sturdily as would like. Spring adjustment range on the RDZ engraver helps some, but is too limited. Leaning towards remixing Pen Mount or make adaptor/sleeve for the bit… Checking out Doug’s LR3 Pen Mount first…
Doug’s mount is regrettably missing the slot for the drag knife. He is too busy to add it, I guess. 
Did you try a smaller point of light? I think the wider light is illuminating the entire arc at once.
Sorry. I do aim to get to it. Had a lot going and struggled to stay motivated enough. Maybe tonight.
No worries, was not meant negatively in any way. Apologies if it seemed so.
Got dimensions? Am staring at Fusion currently…
This one?
Wanting the holder to have cutout/notch for the flange?
Dan remixed Ryan’s drag knife holder and added the slits, let me find it. Printables
The second one with the three slits is perfect, but it is still fixed with zip ties. 
Cheers for link to Dan’s mount, seeing if it’ll work for me as-is without having to remix something. Why do you not use Dan’s? Am using reusable zip ties. Some tool free quick release would be nice.
Edit: Liked Dan’s mount but want reusable ties and ability to attach mini adaptor for mini diamond drag bit.
I am using Dan’s, but I don’t have reusable zip ties. I also thought about the quick release, but am not good enough at 3D modelling. I would love something like Doug’s with the second part being detachable.
I a currently remixing mine to do two things:
Cheers for the suggestions!
Mounting engraver bit to Makita collet resulted in excessively deep gouged scratches. Instead of simply finding/making a weaker spring 
, instead, I created Mount + Drag bit adaptor (for RDZ engraving bit).
Tried drag mount with point light source, better results, but lighting has to be just right.
EstlCam and .SVG if anyone’s interested…
2023-03-05-test.engrave_only.e10.zip (2.8 MB)
This is so cool!
That is much better, The inside of the logo is looking pretty solid!
