Re: CO2 Lasers for CNC Machines

Would someone shed some light on what type of laser system
is used to engrave markings on anodized aluminum, such as
laser type and power. Thanks in advance.

Steve Carlisle

----------
From: Don Hughes <pencad@...>
To: CAD_CAM_EDM_DRO@onelist.com
Subject: Re: [CAD_CAM_EDM_DRO] CO2 Lasers for CNC Machines
Date: Saturday, August 07, 1999 11:16 AM

From: Don Hughes <pencad@...>



MIADsgns@... wrote:

> My previous research into the CO2 lasers found that a 20 watt laser would

be

> necessary for such type of cutting. I even found info on making the laser
> itself but it requires a lot of knowledge and it is a dangerous task

since

> lasers operate with high voltages.

20 watt will cut 3/8" thick balsa(that's about the edge of the envelop),
but there will be some deformation of the sides as there is not enough
power to do it in one pass at 95%-100% power.

You are also absolutely right about the high voltages. If you, or
someone else is not comfortable working with as much as 15,000 KVA's in
the Ma range, I would not even attempt to build one at home. This is not
something to be taken lightly. The lasers will kill you and hurt you in
other ways if ALL the precautions are not known. CO2 lasers operate in
the high infra-red range (10.6 mu) so you can not see the beam, thus you
will blind yourself with the beam if you look into the aperture. Also a
CO2 laser does not burn, it vaporizes, so anything that the beam
contacts it will vaporize. This includes most importantly, skin. Also,
reflected beam from objects will damage eyes as well, so many, many
precautions must first be realized before any undertaking such as this
begins.

>
> I am still hoping that a compact CO2 laser unit can be bought to retrofit

a

> CNC type machine. I am not sure though if the CO2 laser head would be
> mounted on the CNC machine instead of the router head or if it may be
> necessary to use servo driven mirrors to direct the beam, similar to how
> Stereo Lithography Machines move the laser beam and keep the laser head
> stationary.

Many ways to mount a laser head. The most common is to mount the head
stationary from the gantry and use "flying" mirrors to 'bend' the beam
to the focusing lens. The only units I have seen mounted on the gantry's
themselves are the sealed units and used these units will run at
$2000.00 for a half decent one at about 20 watts just to start with.
Then from there all the mirrors will need to be obtained and mounted,
and possibly you will need a power pack or supply as well with that as
well.

>
> Anyone else with CO2 laser experience please jump in. This is a very
> interesting topic and I know there are others out there with similar
> interests that would benefit from this discussion.
>
> Mario

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