K40 laser?

[XEMON]

Hello all,

Not quite 3D printing, but close enough ...

Anyone have direct, hands on experience with the "K40" style ~40W laser?

I've worked with laser welder (~$2M system) but never had one at home ... Any first hand experience would be welcome.

Thanks MCB,
X

[Siress]

I use various industrial grade lasers in that range for marking, etching, engraving, and cutting. Technicians do the setup and maintenance, so I don't know anything about that side of it. And of those I've speced out I get some serious fume extraction and chemical treatment to deal with toxic gasses coming off things like PTFE. The worst part, in my experience, is dealing with kludgy software. CorelDRAW is the worst. Do what you can to get a package that integrates with your CAD package. If you're going to do anything that has a long run-time, you should probably dedicate a PC to the system - even if it's just a simple RasPi, old laptop, or a SFF/NUC.

[XEMON]

Thanks for your input,
fot the pc part, I have an old mini laptop I saved to connect to my CNC lathe so I don't lock up my laptop while uploading the code and I don't have another PC in the garage ... So I'm good that way.

Fumes is a concern as water-cooling ... I here water-cooled machine (worked on too much welders...) But it is a necessary evil here ...

[DocsMachine]

I've got a K40, with some mods. What would you like to know?

Some basics:

One, ventilation is a must. The thing will come with a cheap "bathroom fan" kind of thing, and some even cheaper bulk vent hose. Throw both as far away as you can. I started out with a sort of attic vent fan meant for 4" round ductwork, from Home Depot. I eventually found a more professional 6" fan, used, from a guy that had been using it for ventilating his grow operation.

You will want to rig something to blow the fumes outside- a typical mod is a sheet of plastic, blue styrofoam or plywood cut to fit into a window opening. Raise sliding element of windown, insert board, lower to hold, etc. Smoke from wood is bad enough, but you don't want to be blowing vaporized acrylic or other plastics into your air.

Two, water cooling is also a must. It'll come with a small aquarium pump, which is perfectly workable. I simply took a small 3-gallon bucket, and cut a hole in the top to feed the cord and holes through. Do NOT run the machine without actual circulating water.

Three, you'll want to align the mirrors when you get it. I made this mistake and it cost me some stupid frustration. My adjustments had hot-glue on them, and I assumed that meant it was already aligned. Not even close. There's YT vids on the method, check those out.

And four, it was strongly recommended to me to not even bother with the included software. I've heard everything from that it's just buggy and nonintuitive, to being full of malware. Keep in mind that there's five or six companies in China that make these things, and a half-million distributors, so take that as you will.

I ditched the included in favor of something called "K40 Whisperer". It's free, and uses another free drawing program called Inkscape (itself fairly well regarded) to generate the vector paths. It's easy to use and quite intuitive.

I upgraded mine with an analog milliamp meter (it came with a digital "power output" readout) because there's a limit to how much power you should push through the tube. As I recall (and you'll want to double check, I've slept since I last used it ) you don't want to exceed something like 18Ma, which on my digital readout, was only something like 65-70%. Driving more power through the tube does NOT give you more cutting power at the beam, it just shortens the tube life.

I also ripped out the stock table (which was meant for making stamps, anyway) and first tried a custom-made steel-mesh table, and eventually I upgraded that to a power elevation table.

It works quite well, and I've been able to engrave and cut thin wood and acrylic, and engrave anodized aluminum. (The primary reason I bought it.)

I'll likely upgrade to a better machine at some point, but for the price, it was a great starter machine.

Doc.

[XEMON]

Thanks doc.

You confirmed most of what I read online.
I'm looking at an "older" model (pre digital panel) it seam more basic and less useless electronic with the exact same gut ...

Thanks for letting me know about the aluminum engraving, that will be 90% of what info if I get one ...
Do you have pictures of what you did with aluminum?