Laser engraving logo on back of cabochons

While there's no way I could have provided an answer, I'm going to be watching as well.  Yeah, I still don't cab, but maybe I'll learn something. 

I had access to one made by Epilog years ago and tried it out on some high silica materials like agate and jasper, it worked well. I was pretty careful about what I etched, the machine used mirrors, and in the share shop were people who would use materials that would cloud them, requiring the shop supervisors (I was one) to clean and recalibrate. I imagine newer ones may be better in that regard.
The epilog used vector files so back then Corel was what we used. Inkscape is the popular free one these days. A lot of the chinese machines use G-code, which is more drafting than art, and preferrable in my mind especially if you also cut wood and plastics with it. You need a drafting program that uses .dwg or compatible convertible files, not something that uses proprietary files like google sketch-up. With a vector file machine there are libraries of free to use files out there.
As far as machines, there are some decent chinese ones out there, you just have to look at reviews and do some research on what wattage you want to use. The 60w Epilog took 2 or 3 passes to engrave deep enough on a flat surface stone, and worked okay with a low dome too, I have seen some newer nc routers that can follow a contour, there may be lasers like that as well but the price will no doubt be more than some of the decent under $1000 US stuff available. I think a 50W and maybe even a 40W might do the job, just have to make a few passes.

parfive Thank you kindly for the links, I did not have "zap" in my search terms.. :-) It is pretty amazing how well those rocks are cut with the laser!

I see glennz01 says one should use a high powered CO2 laser. But I am not sure what high power means? 40W or 100W? But then, also, I did read on another thread somewhere that the fiber laser is the way to go. Then in one of those link threads above they were talking about a diode laser? It is very muddling and unclear. It feels a bit like someone would say you have to use a Cabking only, because that is all they have used perhaps?

Is it perhaps just that 100W of any kind of laser would be good? And also, I get the impression that if you use the CO2 one, you have to change the cartridge every someteenth time, and that that costs a packet? So that makes me think if I can get a laser that does not need "recharging" that would be infinitely better. But for all I know, they all need to replace something or other every 5th time you use it? Seriously, I have zero knowledge.

Rockoonz Thank you for the thoughts and ideas! Not sure I understand what a "newer nc router" would mean?

Is there anyone who has tried the different kind of lasers, and can give a comparative judgment between the abilities of the different types? The logo I want to put on would be small, perhaps 3-4mm and just the pen outline of the whale tail you can see on our blue logo at the top left of the message. So this is not a heavy or intense cut needed.

Theo

chris1956 The one that Rob and also Katydid previewed (Diode laser 22W Algolaser Delta) runs on a gantry system, which I feel is too many working parts to last very long.

I do like the compact look of the fiber laser ones, as there are almost no moving parts, only the little mirror in the overhead unit. And the prices on the cheapest versions are not that much more than the Delta one, at a quick look. Pretty darn expensive anyway though.

Something like this one on the big online retailer:
PEKOKO 20W All in One Fiber Laser Engraver,Desktop Fiber Laser 

The one thing I did see and made a mental note of, is that Katydid got a crack in the agate she was etching on from the heat presumably, so perhaps less power but many more passes is something to consider. Keep the rock as cool as possible..

Been using mine for years on same cartrage, to my knowledge anything under 60w won't engrave stone. Some stones work better than others, my laser was in the $4k range, haven't had to replace c02 as I haven't ran it for the 700 hrs or so yet. Fiber lasers are nice but cost a lot more, so depends on your budget

Rockoonz and glennz01 Thank you both for your feedback and thoughts! Appreciate them as this is how we will get forward!

Interesting that the 60W CO2 that you are using does not need the cartridge replaced for so long, so that does make it much better. Does it also run on a gantry like the Delta? But in any case the 4000 dollars price tag is still waaaay too high for my use, which is to just put a logo on the back of cabochons!

Note that the Delta diode laser that Katydid and Rob previewed did etch rock, and I am assuming it was the 22W one (to be fair it may also have been a 40W version, I cannot remember seeing the wattage). They did have to trick the machine for transparent rocks by putting some painters tape on the surface to "focus" the beam, otherwise the laser just went through the rock and did nothing. (Price is roughly around 800 to 1200 dollars odd for the Deltas).

Also note that the 20W Pekoko fiber laser is also 1600 dollars or so, so it is a fair bit cheaper than the CO2 one! But more expensive than the Delta. But it does not work on a gantry, so for me that is a benefit. Less working parts.

I remember doing the reserch and anything less than a 60w wouldn't engrave glass. My machine us also fairly big roughly 200 lbs or so which I can do tombstone sizes and other big things. If it can engrave glass it can engrave stone.


Alternatively if you don't find anything suitable, for about $3 ea plus postage if all same design I could engrave for you. I'll be theoretically snowing my self employment heavy equipment work in 2 weeks and have till April or may for lapidary work.


You can see what some engravings I've done in the past look like in my fb group Alaskan Lapidary and I've got a few photos on my website. Should be reletivily easy to see paint filled vs natural engraving

Yeah I haven't seen much in the up to date lasers, I got mine I want to say around 2016 or so. If your just looking to etch the rocks faster speeds can do ok. I try to stick mostly to agates and similar stuff. I've only had heat break a few rocks if they were too thin and had a big area to engrave in one spot. Whenever my laser does go I'm sure tech will came a long way that I can just buy new and better possibly lol.

One other thing I can add here, I saw an example video of someone engraving on glass with this machine, and it worked fine. There is some dark paper you stick on the glass to focus the laser and where it cuts. But it did work. Window glass is Mohs 6.5, so I cannot see why it would not work on agates and such. Holding thumbs! :-)