On 20 Oct 2014 04:55:43 GMT, "DoN. Nichols"
wrote:

On 2014-10-20, Larry Jaques wrote:
On Sun, 19 Oct 2014 20:03:29 -0400, "Carl Ijames"
wrote:

The sparks travel that fast, yeah, that's what I meant :-). Guess I
shouldn't post while watching football. The Giants just finished losing to
Dallas, and I'm not doing any math, so maybe I'm safe from typos and mental
misteaks (:-)) this time. We have a 1200 W Amada CO2 laser at work, but it
dates from the 80's and moves the sheet, not the laser head, so it isn't
nearly as impressive as current tech.

Perhaps not, but 1200w is nothing to scoff at. I wonder why they
moved the work instead of the cutter, though...

Possibly the laser tube (glass or quartz for CO2, I believe) was
too fragile to accept the acceleration. It is possible to design more
durable tubes, but they probably didn't back then. :-) I'm not sure what
the window material would have to be for CO2 -- perhaps something like
Irtran -- I forget what wavelengths it worked well at. I do remember
lenses for far infrared imagers being made from either silicon or
germanium crystals.

Yeah, I guess the fragility and mirror/prisms were two major limiters
back in the earlier days. I'm amazed that fiber optic cables can take
the heat, though. I woonta guessed that on my own (but I'm an
outsider.)


Let's see -- Nd/Yag lasers were about 1.06 uM (1064 nm) (very near to
red), and I think that CO2 was closer to 10.6 uM

Also -- depending on the size (mass) of the head, it might be
easier to move the workpiece. :-)

More mass than two 4x8' slabs of 1/2" plate? shrug

One possibility would be prisms or first-surface reflectors to
take a horizontal light beam parallel to a support beam, and move the
reflector to turn the beam down from the horizontal to impact the
workpiece. (And, of course, each reflection introduces more potential
positional error, so how precise was this beastie, anyway?)

Enjoy,
DoN.

--
Happiness is not a station you arrive at, but a manner of traveling.
-- Margaret Lee Runbeck