Fiber laser inquiry

[Chuck Thomas]

I've lurked here for awhile now and posted only rarely. I've looked up past posts on fiber lasers and found it doesn't come up all that often.
Currently I work at a machine shop and also instruct at a local community college in the manufacturing field. Both jobs are very rewarding but I'm also being driven to create something more. I don't want to compete with the "trophy" shops in the CO2 market, I know of a few in the area and don't have the time or resources to compete right away. But I've only found one other shop that has a YAG laser and feel there may be room around the area to support another shop.
I recently had a demo on a 20W fiber and was reasonably impressed but felt like it was lacking something. I'm looking for depth of at least .005" as I'm looking into ATF marking standards. I recall Bruce Boone toying with fiber lasers for marking and engraving his rings but haven't read of any conclusions.
Any thoughts from the masses here?

[Bruce Boone]

The fiber lasers are very impressive for the beam quality, fineness, speed, and efficiency. I was blown away when I first saw one. A 20 watt fiber should be able to cut at least .005" deep in steel or other metals. I saw one cutting around .010" to .015" deep. Surprisingly, it cuts silver very easily. Prices are generally in the ballpark of $45K for one. I was looking at doing deeper engraving and was running up to a limit of what was offered in a fiber laser. I found a 40 watt machine for around $65K and finally found a 50 watt laser. That's all I found. In researching it, I found that a limiting factor seems to be the fiber itself. If it gets a beam reflection, it can damage the fiber, which essentially IS the laser. I didn't find any in the 100 watt range, which is about where I wanted to go. I wanted a hybrid that could do deep engraving or cutting. The closest I found was an 80 watt YAG laser with the necessary software and rotary attachment to do the stuff I needed to do. I ordered that and it's on the way from overseas now. I plan to be able to cut earrings from sheet as well as cut and deep engrave titanium rings. The laser itself was pretty expensive at around $120K. I want to also experiment with laser sintering of metals to see if it can do the type of rapid prototyping stuff I've seen. That takes a 50 to 200 watt laser to do that. If the experiments work out, I would have to build the elevator part of the machine. I would suspect that the real machines of that nature are well over $500K. They do custom bone implants and jet engine parts and stuff, where I would just be using it for jewelry.

I don't know how well the laser would do for plastics. I would suspect that heat is heat, and it could do acrylic by brute force, but the wavelength is not optimum for plastics. It would be excellent for anodized aluminum.

[Rodne Gold]

I was investigating a 500w YAG with a galvo head that is linked with a XY table , can cut pieces 500x500mm and engrave that area as well or just mark/engrave smaller fields with the galvo head, cuts thru 6mm thick stuff , was Round $50 000 FOB
Im not at work so can't find the exact one I looked at , but it's similar to this one
http://www.alibaba.com/product-gs/43...g_Machine.html

[Bruce Boone]

Very cool. The 380 volts might be a problem for some people, but the laser power is certainly there. The other part that would need to be investigated is connecting with a rotary axis and having good software to have it work well. Being so much cheaper, there would be plenty of room to add that type of stuff. I would certainly have considered it if I knew about it when deciding upon my laser. I have seen examples of exactly the types of things I want to do from a 50 watt laser of the brand I am getting, so I know with a pretty high confidence level that the system I got will do what I need. Cutting lasers are usually set up to only do cutting and not extreme detail engraving, which would be the majority of the application.

[Chuck Thomas]

I would normally assume that the fiber lasers would be essentially the same across the board, at least where Trotec - Epilog - ULS are concerned but I don't know for certain. If you've seen a 20W fiber burn .010 deep then I wonder what the folks who demo'd for me were missing. We got maybe .0005 to .001 deep in stainless at 100%P and 1%S. Now they ran it as a raster not a vector but they assured me it would act the same. Any hints on getting the deep burn, or is it just a matter of many passes at really slow speeds?

[Bruce Boone]

Wow. That is a big difference. I would think the biggest difference might be the lens from the galvo. It seems to me that the focal point was pretty close, maybe 2" or so since it was set up to do rings. I would assume most fibers like the ones you mention would be longer to handle larger items. That would reduce the power to the target considerably. Maybe those ones use an XY table instead?