Homebrew PCBs

twb8899 wrote:
>  
> 
>>What power CO2 laser do you need for cutting 3mm 
>>steel/brass/aluminium?
> 
> 
> I had a Mitsubishi CNC Laser for several years and have some 
> knowledge of how they work. This machine was a model 1212HC with a 
> 3000 watt resonator and 48" x48" cutting table. The entire machine 
> installation was the size of two pickup trucks...

A laser cutting place near me has an x-y machine about 3m wide, 10m long, and 4-5m high.
The laser is in a hut about 2m long, and the laser looked about 4ft (hard to see inside).
The light is guided to the head thru many metres of fibre-optic cable. They can cut 10cm
of steel (a bit of beam divergence tho). The cable glowed greenish when active. IIRC, YAGs
are greenish?