I myself have a 5.5W diode laser which I have been reasonably happy with, it has been my entry machine into the laser world.
Recently I saw an ad for a 20W diode laser machine.
The technology to achieve 20W looks logical and understandable to me. But how does such a machine perform in real life?
Are there any users here who can/will give an insight into the matter?
There are plenty of videos on YouTube that have reviews of 20w diode lasers. They seem to be a big improvement over 5 1/2 W lasers.
Thank you for the feedback. I have seen some of those videos but am very skeptical when they advertise 40 to 80 watts.
That is why I would like to hear some people from here that I trust, what their experiences are.
Try this site then
Many thanks for the link, it was very interesting reading and the video from the 20 Watt machines is also impressive. A lot has happened on the diode front.
There is a small detail that I hope people see and pay attention to, that is when poplar plywood is referred to and shown in the list as plywood. A misunderstanding can quickly arise and people wonder why it is so hard to cut 3mm (BB) plywood.
The results of the acrylic tests are impressive and I think the same about the possibility to engrave stainless steel.
great,
clean cuts with 3mm ply, burns a little bit with 5mm ply
Welcome to the world of what u see is not what u get.
Ignore videos made by sellers of things being cut ,they are entirely wrong .The first hint is lots of 3d graphics, then videos of cut items with no actual cutting .
They try to say that air assist will fix it …Perhaps if we use oxygen??
Air assist helps with lowering burn marks and keeping the lens clean .But they dont say that .
… 
That’s called LASOX! In around 2003 the company I work for started working with some of guys ( A. Khan & W. O’Neill, cited in that link) at Cambridge University on developing supersonic nozzles for it. I’m not really sure of the current state of the technology but it looked very promising for cutting thick steel.
Most of the time you can read the fine print and figure out that the 40W has 5W optical and the 80W has only 10W optical.
There are a few real 40W LED diode lasers out now and there are also IR laser diodes that can engrave metals and such without a colorant or coating. Some of the lasers now have very small focal points of say 0.06mm and can do a pretty decent job. I mostly find they need a ventilation system and air assist for cutting though.
Nitrogen assist would likely be the best, but air works fairly well and does shield the laser lens cover from smoke/residue.
My most powerful LED is a 437nm 20W optical and I have technically “cut” 5/8" black HDPE, but it is a stretch to call it a cut and took quite a few passes (more than 15). It cuts up to 1/4" fairly well, and as you get thicker it is more of a melt than a cut. I could not cut the 5/8" HDPE with a 70W CO2 laser any better however.
If they could cut clear acrylic, then WOW! that would be fabulous, but they cannot. Maybe the new diode IR 1064nm unit will be able to…
Thanks for the interesting answer. 
After talking to some vendors, and looking at the specifications, the new IR diodes can indeed engrave at 1064nm, but acrylic is still transparent to it so no joy there. CO2 is about 10X the wavelength and so looks like black to the CO2 laser so it cuts it easily. A fiber laser could in theory do it in a small package, if they get the wavelength in the 3000nm-5000nm range but they are still very inefficient and more complex and so cost quite a bit for a hobby/lite-business tool to cut. They can certainly engrave and remove rust and such though, just a bit more costly.
There is not a laser that does everything. Different laser designs work best for specific types of materials. Kind of like other tools. There is no “best” knife edge, it depend on what you are cutting/engraving…
Air assist does help. Instead of browning along the cut the wood stays clean.
It can be cleaned off with vinegar and a scouring pad or a light sand.
I use steal wool or scouring pad to clean off the carbon on the cut surface before my grubby fingers transfer the carbon all over my cut piece.
I am not selling Atomstack, but after using a router for years I’m sold on my M100.
130W gives 20W laser power. The web site claims to cut 12mm solid wood in one cut, but my experience is 5mm ply can get really hot and start a glowing ember which affects the accuracy of the cut.
There is such great real life variation in laser performance its a sham on all of us .
My new 80w model cuts things in one pass that my older 80w would never do in less than 10
the same thing 80w 10w in both cases
is that CO2 or LED laser ?
I am still new with laser cutting and a lot to learn
It is also not surprising, with 80 Watt you do not associate a diode laser. Unless something new has come again ;-), then we are talking about the “collective diode laser”, with 4x5.5 Watt or 7.5 Watt. Then you probably think, ok, but where are the last 50 Watts… - I do that too.
As per the op question diode of course.
I was in dis belief just how much I was scammed by my first 80w diode on the zbaitu .
perhaps we should have a list of the bad ones and the good ones and hope it stays true?
The efficiency of converting electrical power into the leds to cutting power as light,
maybe only 15% converts to cutting power, lost 85%, that’s pretty inefficient.
Thanks. I’m pretty sold on a diode upgrade next in a few years when my tube dies!
We have both a 20 and a 30 watt diode head in-hand, and they’re being put to the test by @JoeSpanier - I’ve also requested a 40W head from xTool. There will likely be a video shootout on our YouTube channel later this year!
