Picking a wattage

[MilkmanDan]

I'm exploring the Epilog lines (Mini & zing) and trying to find the "right fit" for what I'm looking to do....

For personal device engraving, it looks like a lot of people are using lasers in the 30-40 watt range.....if thats the case....what sorts of materials does that put out of bounds?

I'd guess that harder metals (like shop tools) would be out of reach......what about cutting out of aluminum card stock business cards?

Are there rules of thumb you've used for selecting the right wattage (aside from buy the most you can?)

[250 Coupe]

A CO2 laser, at least the kind you and I can afford, can't cut metal. My 70 watt machine won't even make uncoated metal warm let alone leave a mark.

30 to 40 watts is probably a good compromise. Any less and you might not be able to use Cermark on steel and other harder metals. I run aluminum, brass and softer metals at 25% speed and 100% power which may be out of reach with a 35 watt machine. I run almost everything else at 100% speed and 20% to 40% power, a power density that a lower powered machine can reach by reducing speed and increasing power. Laserbits.com lists power and speed settings for Cermark with a 35 watt machine.

I run anodized aluminum at 100% speed and 35% power, again well within the reach of a 35 watt machine.

While I have enough power to cut 3/8" wood, the cut quality is nasty. Either I run out of focus or I don't fully understand the speed vs power balance well enough. I have only tried it once or twice and didn't bother fine tuning it.

Michael

[lepton]

Just went down this road myself and ended up going with a 60W Mini 24.

60W lets me cut 6mm & 12mm birch plywood single pass with acceptable(to me) edge finish.
6mm = 15% speed, 100% power, 500Hz
9mm = 6% speed, 100% power, 500Hz

Also can cut 0.5" acrylic single pass. Could probably cut thicker but the taper becomes much more noticeable.

Plenty of power for marking metals as well as generally running at higher speeds.
Able to mark stainless at 2% speed 100% power. No coating - just the laser - leaves a dark gray mark.

Downside is you need to do a lot of testing - most reference and suggestions I've found are for the 30-40W systems and translating settings for a 60W are not always proportional.

Only 4 month in but am happy with performance and capability.

If I had it to do over again I'd save a few $ and buy my own exhaust fan and compressor - no sense paying Epilog's markup on off the shelf items.

If you have specific materials you'll be using I'd be happy to run a test or two for you.

-paul