Information in this thread is misleading unfortunately. You don't need a gas laser to do this. They are big and heavy. There are up to 100W laser diodes at 808nm wavelength (IR). Interaction of wave with matter is divided into 3 parts which are ; reflection / absorbsition / scattering. When you arrange a high power beam to an object these 3 events depend on the dielectric properties (aka dispersion parameters ; conductivity, permittivity and permeability) and the length of the object. This can easily be seen from Maxwell equations. The incident angle is also a parameter and defined by Fresnel Equations. If you set the angle straight and drive your laser precisely between optimum specs (TE cooling, beam splitting and detecting other part etc). If you don't need an accuracy that human eye is not sensitive (+-1mm out of symmetry) you can easily cut a Coke can with a 1W laser diode. Acrylic and 0.04 metal is a butter for a 1W laser diode. As Bob stated earlier in this thread, fiber lasers are cool and they can have tunable frequency outputs. This tunability will be between approximately 1200nm-1700nm in communication wavelength range.Even if you change the source of your fiber system (put a lower wavelength diode) this system will not work accurately. When you have smaller wavelength penetration depth will be lower thus reducing the quality of cutting process. Also fiber cable will melt if you put a really high power laser diode at source side. Tunable lasers are not for cutting and such, they are for communications. Go and buy a 1W 808nm laser diode, they will usually operate between 1.8V to 2.2V. Design a simple PWM driver circuit and interface to PC using USB or RS232 then you will have a simple laser cutting system ; BOM; 50-60$ On Thu, Jun 23, 2011 at 6:50 AM, Tony Smith wrote: >> At one point, I looked into getting a laser head and attaching it to >> my CNC mill to do my own laser cutting (mostly acrylic, but also some >> ~0.04"-thick metals), but could not find much info online re: what >> type and power of laser I needed. =A0 One laser company (ULS) >> recommended their 30W all-in-one laser head for ~$4000. =A0I expect a >> coke can would require similar power. >> >> Anyway, it seems that there are some laser-knowledgeable people on >> this list, so if anyone knows where I can get info on different laser >> types and powers that I can use to cut acrylic, I'd love to know. >> Might pick up the search again. > > > The 30W laser would have been a YAG type, their wavelength is more suited= to > metals. =A0Actually, YAG really only does metals. > > Ebay is full of $1,000 40W CO2 machines, they will do 3mm or 6mm acrylic > with no problems. =A0Thicker can be done with multiple passes, although e= dge > quality suffers. =A0For acrylic you need to move at a certain speed to ge= t a > nice edge, a higher power laser means you can move faster, or cut thicker= .. > It's a fairly linear relationship. > > Mild steel, say 1mm, can be done slowly & poorly with a 150W CO2. =A0The = same > in stainless would need over 200W, aluminium about 10 times more. =A0Agai= n > more power mean thicker cuts or faster speeds. > > Guide here from someone selling lasers well out of the hobbyists reach: > http://www.laserresale.com/?fa=3Dapp.selecting#cutting > > CO2 lasers output an IR beam, and metals like copper & aluminium are quit= e > good at reflecting that. =A0In fact low powered lasers may have polished > copper mirrors. > > Most companies have CO2 lasers under 100W, hence 'no metals' is common. > > Tony > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .