If you've been around laser engravers for only a short time, you'll be seeing all kinds of claims by various manufacturers and resellers concerning the power of their products. One of the current trends is something along the lines of 'As good as an 80W!' or something similar, making out that their diode laser is on the same level as a CO2 or fiber laser.
These proclamations are often accompanied by images showing brilliant beams of light coming from a rendered image of a laser module, several acronyms which are unexplained but give the appearance of importance, and yet more marketing in various styles. For those of you that have been around for years, you probably already know what a bunch of malarkey most of that stuff truly is.
This article is intended to clear away some of the smoke and mirrors, marketing tricks, and the like. Then, we'll talk about what a laser module's power can do for you.
Marketing Gimmicks of Laser Engraving Industry
1. Laser Module Output Power Tricks
When it comes to diode lasers, one of the popular marketing trends to catch the eye of a prospective buyer is the laser's power. "It's the new Brand A 40W!" This is a good one, because someone new to laser engravers hasn't a clue what that means. They see "40W" on this machine, and "10W" on some other more expensive machine and think to themselves, "I'm getting the 40W, it's a better deal! I'm not getting scammed into paying more for less."
Ah, but dear reader, they are most likely getting scammed. You see, the marketing folks know how easy it is to sucker buyers who think they're super bargain hunters. What the marketing folks are doing is stating what the machine's power consumption is. The laser module itself is a whole different matter, and the output of power from that module is what actually counts.
At the time of this writing, the top output for any diode laser module from a reputable brand of engraver in the sub-$1000 category is 10W, and only two brands carry them*. There are some smaller outfits that will offer a module by itself with a higher output, but you're not going to find them on Amazon and the cost is over the $1000 line.
So, what is the output on the supposed 40W engraver? Chances are that if you scroll and look very closely at the fine print, buried in there you'll probably find that the module is capable of putting out around 5W. That's the most common output across all of the brands in this category.
2. Diode Laser Engraver Vs. CO2 Laser Engraver
The next common ploy is to liken the diode based laser engraver to a C02 laser, in one or more ways, to get the unwary to think, again, that they're going to be getting a fabulous bargain by buying the substantially cheaper machine.
Sorry cousin, it doesn't work that way. A diode laser and a CO2 laser have fundamental differences that will always and forever make them unequal. Even if the outputs are evenly matched, these two work on two different wavelengths of light.
Because of this, you're not going to be cutting clear acrylic with the diode like you can with the CO2, nor engraving on clear glass without masking. At best, one might be able to match at some tasks, but under very specific conditions.
3. Focal Spot Size and Shape
The last one on my list here is the focal spot size and shape. What this is, is the size and shape of the laser beam where it hits the material, (assuming proper focus). There is one particular large name brand which still produces a low end laser module with what is now considered an "unacceptable" size focal spot, (0.25mm square).
Every other brand jumps to use this particular module/brand as the reason why their engraver is better. And in truth, it does actually matter. Though we're talking about something between the sizes of 0.25mm and 0.08mm, it makes a difference.
Some marketing type will probably try to argue that you can't discern the difference with the naked eye. I'd beg to differ on that. It's the char at the edges that make it more obvious, the larger spot will have more char than the smaller.
When comparing lines from different modules that have significantly different spot sizes, it's akin to comparing a freshly sharpened pencil with one that is not so fresh. When we look at the results from not one line but many lines put together, the difference becomes more clear.
An engraving of a photo, for example, will not be as crisp and clean, as the larger spot size is not able to reproduce the image at the same level of detail that the smaller spot can. Edges of letters are more blocky for the same reason. Think of it as the difference between 8 bit and 32 bit graphics, or a 2MP camera and an 8MP.
The Value: Speed Makes Differences in Laser Cutters
Let's assume that, having gotten around the advertising problems, you're looking at two different models. One is a 5W, the other a 10W. (For the purposes of example, we're going to set aside every other factor except the output - don't buy this way). What, you may be wondering, is buying the more expensive one going to get you?
In a word, speed. Over the years, I have reviewed/owned/currently own many different machines which range from 0.25-10W from various companies. Atomstack, xTool, Ortur, Nasum, Sculpfun, Wainlux, Gemitsu, and so on. People have been using machines in the 5W and lower power range for years, making incredible things with them. There isn't a whole lot that my 10W xTool and Atomstack diode lasers can do that the 5W models, and even 3W models, can't. The difference is how fast they can do most of the same tasks.
Take cutting your typical 3mm plywood as an example. The 10W and common 5W engravers can slice through easily enough at 120mm/m and 80% power, single pass. No big deal. Most of those same machines will get through in 4 passes at 420mm/m (Ortur/Aufero being the exception).
At this point though, the 5W models fall away. At higher speeds, up to 1000mm/m, the 10W models can still cut through in 4 passes while the 5W models require more and more passes. Putting this into practical terms, if the length of a cut is, say 1000mm long, and we do 1 pass at 120mm/m, our time to complete that cut is a bit over 8 minutes.
If the 5W requires 6 passes at 1000mm/m (which is generous), our total time to make the cut is 6 minutes, cutting off more than 2 minutes. But we know that the 10W can do this in just 4 passes, which comes out to just 4 minutes. That's less than half the low speed time, and two minutes off what the 5W models can accomplish, 35% faster.
Any enthusiast will tell you that having to wait only 3.25 hours instead of 5 is a whole lot better. This is the sort of thing they strive for, high speed with high quality, tweaking all the parameters to eek out every bit of performance. Any production minded person will tell you that increasing your efficiency by 35% is a significant difference. Being able to pump out 100 keychains in 3 hours and 15 minutes instead of 5 hours can have you up 100 pieces a day easily. Heck, people flying in a plane will agree that shaving off nearly two hours of flight time is a bonus.
Aside from the obvious like cutting, another benefit to more speed is that you can get a far wider range of options to play with. The standard power/speed test is the primary tool used here, as it provides you with a data set for your material. If the machine itself is capable of taking advantage of the laser module's power, the color gradients available in the data set becomes significantly wider.
Where there used to be a couple of yellowish, some tan, and some dark brown, there are now many more colors to choose from. This larger variety enables you to create a more diverse, more complex, and more unique end product. Your product doesn't have to be pretty much the same colors as everyone else's, and that alone is a selling point.
What I've touched on here in this article is, frankly, the tip of the iceberg. There is a lot that should go into the decision-making process for buying a laser engraver, and there are some companies that employ tricks to fool you into buying their lesser product rather than a better one.
Is a laser module with twice the output of another going to give you twice the performance? No.
But there is definitely real world value in buying something like a machine capable of 10W output vs a 5W model. Going the cheaper route doesn't heavily limit you on what you can do, but how fast you can do it.
Again, people have been making amazing things on those 5W and lower power machines for years. If a machine you're considering has an upgrade path to a higher output module, so you can dip your toes now without breaking the bank, even better. The more you can change on a prospective machine down the road, the better for you.
I hope this has been helpful for you. As always, feel free to reach out if you have questions or need help. We all gotta take care of each other.
*Prior to completing this article, xTool dropped a post in their D1 group on Facebook that a 20W laser module for the D1 is going to be released in March 2022. I for one look forward to testing it out and seeing how much added performance it will bring to the table.
Proud xTool D1 Owner
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