Re: [CAD_CAM_EDM_DRO] Digest Number 1463 Laser Levels.

Art Fenerty wrote:

> Bob:
>
> I don't understand how the beam in a laser would wrap around the
> filiment. There is no filiment in a laser. It is an excited gas plasma with
> very low spread from the aperture of the output. Perhaps his point was that
> the laser width would spread over distance.

His description of why is not correct, but the problem of a fairly large
beam that gets wider at greater distance is correct. Unless you use
some sort of collimator to impress a pattern on the beam, it is just
too big for precision alignment. When you are aligning 12 - 18"
diameter shafts of machinery weighing many tons and rotating at
3600 RPM, with couplings that have to transmit 1 million HP, things
need to be aligned VERY precisely! IF you want to align a lathe with
a laser, the only way I can imagine that working is to mount a telescope
on the bed like it was a level, and sight on the laser beam hitting a wall
some distance away. That way, the 'lever arm' of the sight line reduces
the error produced by the width of the laser beam. It would work, but
it is not too practical. The master precision level is much more suited
for this close-in work (on the home-sized lathe, at least). For the
case of a machine with 5 feet between ways, it starts to look more
practical. If you had a magnifier/crosshair on a stand on one bed way,
and a crosshair on a matching stand on the other, and sighted through
the two instruments on a level laser line on a far wall, it could actually
work pretty well. Of course, you could then make a carefully done
chalk line on the far wall, and not even use the laser, too!

Jon