No subject
Fri Oct 15 15:05:20 EDT 2010
for exhausting the toxic fumes that are generated, this will also contain
any stray laser power. Ifyou want to see into the enclosure, you can use a
thick piece of acrylic as the window, as it is essentially opaque to the
wavelength of light generated by a CO2 laser. [I'm assuming a CO2 laser]
On Fri, Nov 12, 2010 at 6:44 PM, Darcy Whyte <darcy at siteware.com> wrote:
>
>
> Here are a few thoughts about the final stages of building my laser cutter.
>
>
> 1) Laser alignment: I was thinking of mounting the first mirror, then
> mounting a block of wood at the location of the 2nd mirror. I can adjust the
> first mirror by firing the laser into the block of wood till the dot is
> where expected. Then move the block to the next mirror and adjust another
> mirror. Eventually the laser will come out of the nozzle.
>
> 2) Visible laser: If I want to get a laser pointer and add it as a guide as
> to where the laser is about to burn, any suggestions for that? It might be
> nice to have a visible dot where cutting is about to begin. Where to get a
> good pointer for this? What about other ideas of knowing where the laser
> will burn. This is just for doing stuff like finding (0,0,0) and such. An
> alternate idea is to have two small pointers attached on the laser cutting
> nozzle. They would be angled to reach the focal point. So if the laser is in
> focus, the two dots converge and we can see the cutting point. If out of
> focus, we see two dots. Another idea might be to have a post coming down and
> the laser is a certain offset from that.
>
> 3) Stray laser power. The beam starts at about 1mm width. The 50mm focal
> length lens will then bring it to a smaller cross section for cutting. It
> will obviously diverge at distances over 50mm. I figure it will be back to
> 1mm width at a distance of 100mm from the lens. At 150mm, it will cover 4
> times the area so the power will start to be more spread out. So if the
> cutting surface is like 150 or 200mm from the table, then the laser will not
> heat the table too much.
>
> 4) Cutting table. I'm making a cutting table out of some chicken wire like
> stuff I was given. I'm planning on stretching it over a rectangular frame so
> that it is nice and flat and rigid. I think that the laser will heat it but
> not too much as it's metal. I guess it it wears out quickly I should try
> some different material.
>
> 5) The laser high voltage terminals stick out of the glass and are about
> .2" long. They are about 60 thousands of an inch thick. For testing I used
> some thin copper wire to wrap the high voltage wires onto it. I then used
> electrical tape and some thick rubber tubing to insulate. For production,
> there must be some sort of connector that can slip on the pegs and be okay
> with 25,000 volts. Any ideas?
>
>
>
> _______________________________________________
> Discussion mailing list
> Discussion at lists.hacklab.to
> http://lists.hacklab.to/cgi-bin/mailman/listinfo/discussion
>
> This is a private list. Make sure you get express permission from the
> authors before you forward any messages elsewhere.
>
--20cf3054a4a989c9050494e5faf2
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable
For option 2 something like this: <a href=3D"http://cgi.ebay.ca/Beam-Combin=
er-optic-mirror-CO2-Laser-Red-diode-CNC-/160363511773?pt=3DLH_DefaultDomain=
_0&hash=3Ditem255668ffdd">http://cgi.ebay.ca/Beam-Combiner-optic-mirror=
-CO2-Laser-Red-diode-CNC-/160363511773?pt=3DLH_DefaultDomain_0&hash=3Di=
tem255668ffdd</a><br>
<br>From a safety perspective,put the laser in an enclosure,you will need t=
his for exhausting the toxic fumes that are generated, this will also conta=
in any stray laser power. Ifyou want to see into the enclosure, you can use=
a thick piece of acrylic as the window, as it is essentially opaque to the=
wavelength of light generated by a CO2 laser. [I'm assuming a CO2 lase=
r]<br>
<br><br><br><div class=3D"gmail_quote">On Fri, Nov 12, 2010 at 6:44 PM, Dar=
cy Whyte <span dir=3D"ltr"><<a href=3D"mailto:darcy at siteware.com">darcy@=
siteware.com</a>></span> wrote:<br><blockquote class=3D"gmail_quote" sty=
le=3D"margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204);=
padding-left: 1ex;">
<div><br></div><div><br></div>Here are a few thoughts about the final stage=
s of building my laser cutter.
<div><br></div><div>1) Laser alignment: I was thinking of mounting the firs=
t mirror, then mounting a block of wood at the location of the 2nd mirror. =
I can adjust the first mirror by firing the laser into the block of wood ti=
ll the dot is where expected. Then move the block to the next mirror and ad=
just another mirror. Eventually the laser will come out of the nozzle.</div=
>
<div><br></div><div>2) Visible laser: If I want to get a laser pointer and =
add it as a guide as to where the laser is about to burn, any suggestions f=
or that? It might be nice to have a visible dot where cutting is about to b=
egin. Where to get a good pointer for this? What about other ideas of knowi=
ng where the laser will burn. This is just for doing stuff like finding (0,=
0,0) and such. An alternate idea is to have two small pointers attached on =
the laser cutting nozzle. They would be angled to reach the focal point. So=
if the laser is in focus, the two dots converge and we can see the cutting=
point. If out of focus, we see two dots. Another idea might be to have a p=
ost coming down and the laser is a certain offset from that.=A0</div>
<div><br></div><div>3) Stray laser power. The beam starts at about 1mm widt=
h. The 50mm focal length lens will then bring it to a smaller cross section=
for cutting. It will obviously diverge at distances over 50mm. I figure it=
will be back to 1mm width at a distance of 100mm from the lens. At 150mm, =
it will cover 4 times the area so the power will start to be more spread ou=
t. So if the cutting surface is like 150 or 200mm from the table, then the =
laser will not heat the table too much.=A0</div>
<div><br></div><div>4) Cutting table. I'm making a cutting table out of=
some chicken wire like stuff I was given. I'm planning on stretching i=
t over a rectangular frame so that it is nice and flat and rigid. I think t=
hat the laser will heat it but not too much as it's metal. I guess it i=
t wears out quickly I should try some different material.</div>
<div><br></div><div>5) The laser high voltage terminals stick out of the gl=
ass and are about .2" long. They are about 60 thousands of an inch thi=
ck. For testing I used some thin copper wire to wrap the high voltage wires=
onto it. I then used electrical tape and some thick rubber tubing to insul=
ate. For production, there must be some sort of connector that can slip on =
the pegs and be okay with 25,000 volts. Any ideas?</div>
<div><br></div><div><br></div>
<br>_______________________________________________<br>
Discussion mailing list<br>
<a href=3D"mailto:Discussion at lists.hacklab.to">Discussion at lists.hacklab.to<=
/a><br>
<a href=3D"http://lists.hacklab.to/cgi-bin/mailman/listinfo/discussion" tar=
get=3D"_blank">http://lists.hacklab.to/cgi-bin/mailman/listinfo/discussion<=
/a><br>
<br>
This is a private list. =A0Make sure you get express permission from the au=
thors before you forward any messages elsewhere.<br></blockquote></div><br>
--20cf3054a4a989c9050494e5faf2--
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