I found a free Synrad 10 watt laser (doing 17 watts!) in a scrapped semiconductor programming machine and built a bracket to bolt it to my milling machine. I bought a ZnSe lens on ebay for $25, and so now I am making photons!
I machined a holder for the znse lens (3″ focal length). I use shop air with a homemade dessicant dryer and filter at about 10- 30 PSI. Seems to work fairly well, and hopefully keeps my lens debris free. I am getting a focused spot of about 0.014″, which is fair, but I would like it a bit smaller. I have a couple of 1.75″ F.L. lenses I could try…
I use Rhino 3 for my CAD and VisualMill 5 for my CAM. My cnc mill runs the free opensource linux based EMC software. I am working on a 4th axis based on a 10″ rotary table….should be pretty cool for engraving round objects.
I am amazed at the speed such a small laser will cut things. I am staying away from plastics except for acrylic because of the toxic fumes. I have not tried glass yet, but reading the posts about how people do it with 9 watts makes me think it will be possible on my little system.
My background is Electrical Engineering. I have been into lasers as a hobby since I was 12 and got my first HeNe. I am currently tinkering around with some larger CO2 lasers (90 watts) that were scrapped because they need a recharge and are no longer supported by the laser company (coherent). My initial experiments with refilling them are promising, but I don’t know if the gas fill will last for very many hours. The little Synrad is nice even though it is so low power because it just sits there and works with no complaints.
I have been lurking here for a few months. Several pros, new and experienced, discuss some details of laser engraving but, I am disappointed to say, not a lot of do-it-yourself stuff here. Not a lot of tech talk about laser delivery optics. That could change anytime, though.
Yeah, I looked through some past posts and now realize these guys are more about actually using lasers to make money. Gasp! :-)