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[Q] How do they do it "Crystal and Wood 3D Engraving"

PostPosted: Sun Jan 20, 2013 2:25 am
by nephertiti
Hello,

I'm so close to finish my 2.x Laser. Just cutting/engraving few things and learning stuffs.

So when I google 3d laser engraving I found this pictures:

Question is ; Is there any way I can do same things with 2.x laser and LO DSP?

If answer is no , how they did it?

Thank you.

Re: [Q] How do they do it "Crystal and Wood 3D Engraving"

PostPosted: Sun Jan 20, 2013 5:43 am
by TLHarrell
The 3D stuff, yes you can. It's a matter of multiple raster passes. I'm not sure about the software for the LO DSP, but I know Retina Engrave now supports this function natively in software. If it doesn't support it, you simply have to sort out the layers yourself and load each one up for each engraving pass.

The 3D crystal thing is a much different beastie. There are multiple beams on the specialized equipment. Where they interfere is where a small fracture is formed. It is some sort of visible light laser combination, somewhere in the green range. No idea of the wattage rating though. Not something that can be done on a 2.x nor any other CO2 laser setup.

Re: [Q] How do they do it "Crystal and Wood 3D Engraving"

PostPosted: Sun Jan 20, 2013 6:41 am
by macona
The crystal thing is done with a Q-switched yag laser. It is a 3 axis set up where they can position the block in X, Y, and Z relative to the lens. The laser is fired and the glass breaks down at the focal point inside. X and Y beam positioning is done with a galvo system.

Here they use a frequency doubled yag, 532nm. I wonder if the one I have is powerful enough to do this.

-Jerry


Re: [Q] How do they do it "Crystal and Wood 3D Engraving"

PostPosted: Sun Jan 20, 2013 4:02 pm
by nephertiti
Thank you for answers.

About wood engraiving which wood type I can use?

As you can see in picture it looks realy deep engraving , with 40w laser is it posibble?

And for 3d engraving Z axis needed?

Re: [Q] How do they do it "Crystal and Wood 3D Engraving"

PostPosted: Sun Jan 20, 2013 10:22 pm
by macona
Epilog machines also have the 3D engraving capability. I believe depth (power) is related to a grayscale image. It has been a long time since I used one.

Looking at the chinese machines it looks like even the large ones are only about 1.2 watts average power at 3khz rep rate. My green is about 7 watts at 10khz rep rate. Ought to do it. Need to see if I can get one of the galvo scan heads I have working.

Re: [Q] How do they do it "Crystal and Wood 3D Engraving"

PostPosted: Mon Jan 21, 2013 7:23 pm
by TLHarrell
A 40w laser will easily engrave most woods. The image above appears to be basswood which is very evenly textured grain and quite soft. Should engrave really easily.

Re: [Q] How do they do it "Crystal and Wood 3D Engraving"

PostPosted: Mon Jan 21, 2013 7:29 pm
by BenJackson
TLHarrell wrote:A 40w laser will easily engrave most woods. The image above appears to be basswood which is very evenly textured grain and quite soft. Should engrave really easily.

In fact, without implementing PPI for engraving yet, I've found it can be tricky to not engrave *too* deeply in wood, since power only goes so low and scan speed is the only way to reduce effective power.

In fact, I only lately realized that PPI also means that you have a shot at engraving effectively during acceleration.

Re: [Q] How do they do it "Crystal and Wood 3D Engraving"

PostPosted: Mon Jan 21, 2013 11:19 pm
by TLHarrell
PPI would be nice, but not an option on my current machine. PPI would likely also eliminate a lot of potential for charring, from what I've heard.

Assuming from that plaque being around 10-12", that would be many hours of engraving on my machine. Regardless of whether the software sets it up natively or not, not really something I'm interested in doing with a laser except maybe to play with in a small capacity. I haven't done anything with 3D engraving on mine yet.

And my poor tube died. Time for a replacement.