CO2 Laser Bed

I used vulcanized fiber for our CO2 laser. It will absorb the laser and char, but it will not support combustion.

Is this like vermiculite board? The stuff used to board out behind log stoves.

You could check with the folks that used to make them for the Space Shuttle.

I used a 1/4" carbon plate, but in my case the material being cut was a metal ribbon moving in steps past the laser, so the beam followed back and forth along the same path all the time. The plate was only about 5 x 10 cm. I never saw any degradation of the plate.

Hi dk

would that be a CO2 laser? Where would I get a carbon plate?

Thanks

Yes, it was a 125W Synrad CO₂ laser. We were cutting slits in thin (0.002-0.004", 0.05-0.10mm) foils of high-nickel alloys such as Hastelloy-X. The machine has since been re-purposed, and the laser is sitting in storage.

We use a lot of graphite as molds for high temperature vacuum forming, but as I recall the plate I used was denser than the graphite we currently use. I have no idea what happened to the plate. It was located an inch or two (25-50mm) below the material being cut.

We have McMaster-Carr, a marvelous company here in the USA that carries an incredible variety of industrial stuff. They are not the cheapest source, but they usually have what we need, and they get it to us fast. It is not unusual for us to order something in the morning, and get it the same afternoon, shipped from their LA-area warehouse to our plant east of San Diego. One possibility is 7971A11. In case that link does not work, the full URL is http://www.mcmaster.com/#carbon-plates/=yaivpl

I have no idea whether they ship to the UK. If not, a good welding supply company should have something similar.

If you are cutting shapes in wood, you could drill an array of holes through the carbon, and push nails through the holes. The nails could then be replaced as needed.there would have to be another layer of metal or carbon underneath to support the nail heads

Good luck!

Great info dk may look it up. The nail bed does work also because the laser gets progressively out of focus below the cut. As you say 2 inches should be ok.

Another source for graphite plates is from EDM supply companies. They sell all grades of graphite in many shapes

Right! I forgot about that! We are indeed using graphite electrodes for plunge EDM, both in sheets (0.018" thick) and in machined blocks. The current main project uses blocks that start out about 2x2.5x9".

For some of our vacuum forming, we use graphite blocks up to around 4 feet square and around 10" thick.

I assume that the "wallboard adhesive" is what we call sheet rock joint compound in the US. I checked the MSDS (DAP brand for example) for a few brands, and could not see any hazards in your application. If this works for you, I would stay with it.