Beam Dumps

Here is a thought I figured I would bring up. Simple diode lasers make due just fine with flame-resistant MDF as a cutting bed. As they become higher powered, a metal bed (honeycomb particularly) becomes much more popular. What I don't see much of is the ideal materials used for a beam dump beneath this.

I have seen some designs where the beam goes straight through to the base and other more negligent ones where there is fragile mechanical or electrical equipment present. I understand a laser beam becomes less abrasive as it goes out of focus but this seems poorly thought through for something of such high power. Especially if you are trying to avoid beams reflecting onto a viewing panel or other burnable material.

Does anyone have some good or bad experiences to share? Or thoughts on what makes a good safe base?

Thanks,

... if the laser power or energy density is below some ten Watts, then a black matte tile is enough.

Non focussed laser energy in comercial units with up to some hundred Watts or even Kilowatts is absorbed by graphite, sand or water ...

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Viktor
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Sorry for the late reply Viktor,

Yeah, makes sense. I still can't quite get over those cheap CO2 lasers that don't seem to have an obvious base to them. Is that just negligence or do some not require more than a little aluminum. I'm talking 40 watts minimum on these ones.

Thanks,

... when focused, it will heat and oxidize the metall, but 40 Watts aren't enough to cut or evaporate it ... when outside the focus area, it's even lesser heat, so no real problem for a thin metal sheet ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]