Lasers are friggin’ awesome. I think it’s safe to say that isn’t a controversial stance. Not only are they awesome in pop culture, with laser guns and laser-wielding sharks, they’re awesome in a workshop where they cut things with nothing but focused light.
Makers are confronted with so many choices of laser cutters and engravers that it can be intimidating. I’d like to guide you through a rough outline of the main differences between the lasers you’ll find on the market today, in order to help you choose.
WHAT’S AVAILABLE?
For a typical home workshop or a makerspace, there are three main options. From cheapest to most expensive, you have diode lasers, CO2 lasers, and fiber lasers. Prices can range from a couple hundred dollars to tens of thousands, so it’s important to make an informed decision.
WHICH ONE DO I NEED?
That is the key question, isn’t it? Your decision will be determined by what you intend to do with it, and of course your budget. To make things easier, I’ll focus on four main factors: price, speed/power, size of work area, and whether or not it can work in metal. I’ll elaborate more on each technology afterward.
THE LOWDOWN
- Diode = cheapest, slowest, mid/huge work area, don’t cut metal*
- CO2 = mid price, faster, mid/large area, don’t cut metal
- Fiber = expensive, fastest, small area, do cut metal.
DIODE LASERS
These are becoming so common, I see them everywhere now. You’ve seen them too. They are a simple, open-air X-Y gantry with a block mounted on it that contains a laser diode. These operate in blue light, typically around 450 nanometers (nm) frequency. They’re very cheap because the components are readily available and there just isn’t much involved in their construction. They’re comparatively very weak though. Their output is going to be 20W and lower, and they get to this power by combining multiple 5W–6W diodes into one beam internally.
*metal engraving — There’s a new slate of diodes in the 1064nm range of infrared (IR) light, which can engrave metal.
The 450nm frequency of laser light can engrave and cut materials like wood, paper, and leather, but will bounce off highly reflective surfaces and won’t affect metal at all. Typically these units are small, with a working area under 2 feet square on even the largest, and most being smaller than that. However, they’re extremely light and sit on the work surface. Using software like LightBurn to create massive art, you can simply move the entire unit on top of the work surface, lining up individual sections of a much larger complete design.
You will find these starting around $150 and going up from there. Machines in this category:
NOTE: A frustrating trend in this market is to advertise diode lasers by the power draw of the entire machine as opposed to the actual output of the laser. You’ll see a “150W” machine advertised that actually has less than a 10W output. So far, we only see this in cheap diode lasers and not the other types.
CO2 LASERS
CO2 lasers are typically seen as a big box with a gantry inside. These use a giant glass (or sometimes aluminum) laser tube that produces light roughly at the wavelength of 10,600nm or 10.6 micrometers (µm). These start at 30W and can go up to hundreds of watts. They’re capable of engraving and cutting absorbent materials, and especially at higher powers, even reflective and clear materials like glass. However, this frequency does not allow them to engrave metal.
CO2 lasers gain speed over diode lasers simply by being more powerful, so they can cut things in fewer passes. They’re also often built with much beefier motors and gantries so they can move faster. The smallest of these machines will fit a standard piece of printer paper and they go upward from there, quickly becoming the size of a small car.
You’ll find these starting around $400 for small models like the generic K40, and going up from there. Some machines in this category:
FIBER LASERS
Fiber lasers typically look like a pedestal with an arm cantilevered over a work surface. Mounted on the end of that arm is a galvanometer, a set of magnetically controlled mirrors that can aim a laser beam with extreme speed and precision.
Fiber lasers operate in the 1064nm range of infrared light, and their biggest selling point is that they can engrave and cut metal. You may be able to “mark” some metals with other lasers, especially with the additional use of some kind of coating, but a fiber laser will actually ablate or remove material from metal.
Due to the use of a galvo, fiber lasers are extremely fast. And they’re fairly powerful, combining several diode lasers into a single beam via optical fiber. Unfortunately though, the work area is typically small, only a few inches in any direction.
You’ll find these starting around $2,000. Machines in this category:
• Monport
• Cloudray
THE OUTLIERS
Each of the generalizations above has its outliers. For example, you can find a galvo-based diode or CO2 laser, and there are gantry-based fiber lasers pushing thousands of watts for cutting steel panels! However, for the home/hobby market, the machines outlined here are typical. Start with these to begin your research and find the optimal laser for your needs. 
Best DIY Upgrades to K40!
To hot-rod an inexpensive K40 laser cutter, check out “Make That Laser Blaze,” Make: Volume 81.
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