Galvo CO2?

[Trey Tull]

I was browsing around the RayFine site looking at fibers and noticed they had a 60w galvo co2 machine with a 300x300 engraving area. I have a job that requires marking small (.4"x.6") metal parts (using cermark) and my Universal has no problem marking them but it takes time. The text on these parts is tiny and it needs to be very legible. Does the text or image become distorted the further out you get towards the edge of the engraving area. What sort of a spot size am I look at with a 300x300 area?

I know Jit has one that's collecting dust but I'm not sure what he was using it for. I'm thinking about one just for this specific job.

Thoughts?

[Gary Hair]

I don't have a galvo co2 but I do have a galvo fiber. I lose a bit of power at the extents of the working area and I'm sure the spot size is a bit larger, however, the anodized aluminum I mark turns out fine no matter where I mark it. One big issue with galvo is going to be focus and alignment. The farther away from dead-center of the lens you get the more effect you see from having the galvo head slightly low, or high, compared to precisely focused. If you are marking directly below the center of the lens and move the table up and down you won't see much change in the image. Move to a place farther away from center and when you move the head down then the image will shift toward center, up and it will shift away. That may not seem like a big deal but with the parts I mark, some about the same size as you are marking and some slightly smaller, the alignment can get off pretty quickly. I mounted a DRO to mine so that I could get .01mm repeatability and don't have any problems, but things go wrong so much quicker with galvo than flying optics.

[Kev Williams]

What I've personally found with Cermark, extra speed is useless. Cermark requires a certain amount of dwell time for it to fuse well to the metal. I bought my 80w Triumph specifically because I believed- wrongly - that with double the power, I should be able to crank out parts twice as fast. That didn't happen, at all. To get decent results on the Triumph I can't run it any faster than my 30 and 40 watt machines, plus I have to lower the power account for the speed; too much power and the beam literally vaporizes the Cermark- it leaves a nice permanent marking, but it's 'holographic' bronze-ish gray, that lightens considerably at different viewing angles. It's okay for some jobs, like hanging valve tags that will spend their life 2 miles underground in a mine shaft, but not good for "aesthetic" jobs, which accounts for 99% OF my jobs.

[Dave Sheldrake]

For Cermarking a CO2 Galvo is a waste of money, it won't work any faster than a cheaper 40 watt Gantry machine.

Speed is great, if you can use it...in this instance it won't make any difference

[Mike Null]

Kev
My experience is opposite yours with respect to Cermark and power. I was able to double my speed when I got my new 80 watt machine versus my old 45 watt machine.

I run both at 100% power and 600dpi but twice the speed on the new one. The old tube is operating at full power so that's not a factor.

I do agree with you when running very thin materials.

[Kev Williams]

Mike, I'd love a more powerful RF machine, I'm sure the nature of the beast, aka a DC glass laser, is the main reason for my results. The sad irony is, this beast will produce nearly identical results on Rowmark to my RF machines, but it's so slow at doing it that I rarely use it for that, usually when the other 2 machines are 'taken' and I need to keep someone happy! Slow beats not at all!

The main reason I haven't invested in a high power RF machine is because of the nature of my work, a lower cost extra machine will help me much more than a higher cost faster machine. (it's why I have so many machines!) I bought Gary's 30w GCC as I was getting inundated with water bottle orders, so I needed another RF machine with a rotary. But then I sold my little 25w ULS to my BIL, and in retrospect I never should have, about twice a week I wish I still had it! Because: a 25w machine would be of more use to me in addition to the 30w GCC, than say, an 80w GCC by itself...

So I guess I'll never know the luxury of high-speed single-machine Cermarking!