Re: [CAD_CAM_EDM_DRO] Laser links ?

John wrote:

> I'm not sure but I would think you're right with lots of little holes. When
> I saw the guy writing his name on the glass it wasn't a continuous line, in
> fact it shattered quite a bit and was made using lots of small cracks. That
> may be due to the nature of the beam, being pulsed n' all, but still at a
> high rate. Trying to pulse a CO2 laser may prove tricky, the cheapest way
> would probably be a Q-switch which is a tiny motor with a mirror on it.
> They're used on crystal lasers so none of the light can escape from the
> crystal while the molecules in the crystal begin to laser and saturate. The
> motor moves very quickly and has a microswitch on it to tell the laser's
> flash lamps when to fire. It all has to be timed very nicely so that the
> mirror is aligning up as the lamp fire (And we're talking micro to nano
> seconds here).

That's probably not a mirror but a diffraction grating. Most Q-switches
don't need to move the grating very much, they use piezoelectric drivers.

> I still think the best idea is a mechanical mode of cutting and then
> polishing with a lower pressure water jet. A laser is definitly one of those
> things I'd like to build if only I had enough £££'s. :-) Can't really
> think of a use for one, I just want one, isn't that good enough? Here are
> some links anyway:

CO2 lasers are actually pretty easy to build. There are web sites that will
sell you all the difficult parts for a few hundred $, and you get the rest at
the local hardware store. Pulsing them is not too hard, either, but you
can't get nS pulses without a Q-switch. A Q-switch is probably beyond
the capabilities of most home shops.

Jon