pics of new mill attachment and machining question

So I finally got around to machining the parts to allow me to bolt a small CO2 laser to my Shizuoka bedmill head.

Here is the unit:

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I wanted it to be relatively easy to take on/off the mill, because it is somewhat in the way when trying to use the mill as a mill :-) The laser is a 10 watt Synrad doing 17 watts.

Here is a closeup of the lens holder I machined on the mill:

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I used a 3" F.L. znse lens, an indium wire seal, and dry shop air at about 20psi when cutting stuff.

Here is a little gear I whipped out in under 18 seconds at a 60IPM feedrate in

1/16" basswood:

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Oh, and to make you really jealous...I scrounged the laser for free from the dump (a semiconductor marking machine that had been obsoleted) and got the znse lens on ebay for $25. Not a bad addition to my $200 Shizuoka B-3V mill! :-)

Oh, and the question. I need a way to hold down small wood and cardboard parts while cutting them without having much on the backside. The parts get really charred on the backside if they are just resting on a piece of annodized aluminum plate. The best thing would be a vacuum honeycomb table, but I am not sure how I could machine something like that. Any ideas on how to make an aluminum honeycomb table about 12" by 20" by 1/2" thick with as thin a webbing as possible and having vacuum holddown? The best I can come up with is drilling a bunch of closely space holes in the plate, or perhaps making a bed of nails (but then how to do the vacuum holddown?).

Thanks,

Rick

Reply to
Rick
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were did you find the laser and what will you make????

Reply to
HaroldA102

really really jealous

Reply to
williamhenry

This makes me want to run out and go dumpster-diving for lasers and try myself. Maybe I'll meet someone who's trying to do the same thing, and I can ask he/she what a F.L. znse lens is, where to put the indium wire seal, and why that is needed. But I'll have to find a $200 mill with CNC first.

For a support table, wouldn't a non-reflective surface prevent charring of the backside? Black anodized aluminum? I know very little about laser cutting, but it seems that you can cut a wood piece pretty fast without burning into a metal undersurface.

Using a vacuum table, you'd need to plug off the holes which aren't covered by the workpiece for good holding power. You can use thin closed-cell urethane foam for this, say 9 x 12" sheets with a pattern of holes to suite the shape you are cutting. This stuff is available at Walmart and craft stores as Foamies or FunnyFoam, 2 mm thick--either plain or adhesive-backed.

What I really envision for myself is a laser printer which will engrave wood, not neccessarily cut it. At 300 dpi. Is this possible to cobble together? What's the smallest laser unit that can be attached to a lightweight x-y CNC table which will do this? Why can't "they" make a small laser engraver as cheaply as paper printers are these days?

Ken Grunke SW Wisconsin

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Coulee Region Woodturners AAW chapter
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Reply to
Ken Grunke

You have to mask the unused portion. A plate with a lot of holes works fine. Charlie

Reply to
Charlie

F.L. = focal length, ZnSe is Zinc Selenide, one of the few transparent materials that will actually pass the 10.6um wavelength of the CO2 laser, Indium is, well, Indium. A very soft metal that is pretty good for thermal seals.

I tried a black anodized piece of aluminum. The problem is the backside of the wood that is against the aluminum gets covered in a sticky brown mess. I guess it is sap+charred wood or something. If the wood is suspended over air, the backside is clean as can be. Most of the comercial laser cutters use a honeycomb table.

Yeah, I actually cut some of that 2mm foam with the laser....makes a nice cut.

You can engrave wood with a very small laser....2-3 watts. Unfortunately, there are not any 2-3 watt CO2 lasers that I know of. Well, maybe ones that are dying...

Once you see this thing cut 1/8" acrylic with details so small they would be hard or impossible to do with a milling machine, you would want to do more than engrave. :-)

I saw a gimbled eyeball thing when browsing the web tonight for halloween ideas, drew up my own version in Rhino 3 in about 45 minutes, converted it to g-code in VisualMill 5 in 5 minutes, and cut all of the parts (twelve) out of 1/8" acrylic in about 2.5 minutes. From idea to parts in hand in under an hour! Of course I still love making metal chips with my mill, but I see many uses for this little attachment.

Rick

Reply to
Rick

hey! good idea. Heater cores look like honeycomb?

Another guy suggested the cores used when making wakeboards. He seemed to imply they were aluminum honeycomb. I don't know if there are any wakeboard manufacturers in Seattle...

Thanks,

Rick

Reply to
Rick

It's pretty commonly used in monocoque racing car chassis also.

Texas Parts Guy

Reply to
Rex B
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Proper capitalization makes a big difference in understanding this. I thought that it might be a material, or it might be a brand name, but lacking the capitalization, I could not tell which.

Hmm ... could you also be burning the dye out of the anodization of the aluminum? What does the aluminum look like after your pass?

Enjoy, DoN.

Reply to
DoN. Nichols

Okay, waitasec. In a later post you said you were in Seattle. But I'm in Seattle, and we don't have dumps, we have "transfer stations" that you can't scrounge from. Where exactly is this dump of which you speak?

Reply to
Walter Harley

Good catch. :-) I use dump as a generic term for stuff that has been discarded by companies. No chance that I am going to reveal my watering hole though. Just last week I fished three small argon lasers and power supplies, 6 linear rails and carriages, about 20 pittman motors, some hydraulic motors, valves and cylinders, and a flowing gas 40 watt CO2 laser.

My wife thinks it is mostly junk though. :-(

Rick

Reply to
Rick

On Sat, 07 Aug 2004 17:06:12 GMT, "Rick" calmly ranted:

Ooooooh! Ahhhhhh!

PLEASE give your wife my address, Rick. ;)

Reply to
Larry Jaques

On Sat, 07 Aug 2004 21:12:51 -0700, Larry Jaques calmly ranted:

To clarify that, I'm not asking you to send her to me. Instead, please have her send all that horrible "junk" to me.

Reply to
Larry Jaques

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