Re: CO2 Lasers for CNC Machines

In a message dated 8/7/99 6:24:59 PM Hawaiian Standard Time, MIADsgns@...
writes:

<< am interested in knowing what the charge is for cutting wood. By the hour?
Linear foot or laser time? >>
Mario,
I can't really tell you how they figure out pricing. I think it is per
minute or per inch, which ever is more. One of the big charges is the
programming. If I e-mail acad 12 .dwg files to them, they don't charge me the
cad time, just a few minutes of posting time and the actual cut time.
Sometimes I supply material, most times they do. We have quit lasering wood
as the charcoal edges left behind make a mess of your hands and anything they
touch. Some woods have a bad odor after being laser cut. Plexiglas and most
metals in contrast cut like a dream. No deburring is required. (Aluminum is
the exception, it has a fuzzy dross that clings to the bottom.) The edge is
not square on thick material and there is a HAZ or heat affected zone all
along the cut. This can be tough to cut with HSS if further machining is
required. Carbide cuts the HAZ of low carbon steel no problem but on tool
steels, it gets too tough. We grind away a "nub" which we program in
wherever we need to machine thru the HAZ. The laser shop has also engraved
metal by etching at low power. This looks more like a high current wire being
dragged across the surface. It was not useful to anybody and as far as I
know, they no longer do it. Copper is one metal they will not cut.
Apparently, the machine has polished copper mirrors. They have choosen a
wavelength that will not affect the mirrors. Thus it won't cut copper either?
This I don't know the underlying reasons. Hope this helps.

Peter

BTW Mario, We are in the middle of the Pacific but if you want to contact the
laser shop, I can supply you with their e-mail address.