At 20 watts, the Atomstack S20 Pro has build quality, ease of use, and portability that make it a great choice for those looking for extra laser cutting power. But quality power supplies do come with a hefty cost.

Over the past few years, there has been an arms race over overall laser power. Machines started at around 1.7 watts, then 5.5 watts; late last year we started seeing some 10-watt machines, like the Atomstack S10 Pro. We're starting to see comparisons to bigger CO2 machines.

That's why this machine from Atomstack becomes very interesting.

The Atomstack S20 Pro is the top of the Atomstack product line. That's how the S20 stacks up against the rest.

For controls, you can use any software you want, like my favorite Laser GRBL or Lightburn.

It can be connected directly via USB or Ethernet. Atomstack also has a rather limited application, but still controls the basic functions of the machine.

One advantage that Atomstack offers is an external touchscreen controller. You can move the machine, monitor it while it's running, and load files from a USB that plugs directly into the controller.

I've found this handy in the past when I didn't want to connect my machine to wifi and didn't want to connect a computer.

The Atomstack S20 Pro also has limit switches on the x and y axes. This allows the machine to find its home position before each engraving/cutting begins. This is useful if you are making repeated cuts in the same location where the workpiece is centered. Even if you turn off the machine, it can find a predefined position because it can always start from the same starting position.

In addition to the increased laser power, another major improvement to the S20 is the addition of a fully integrated air assist system.

Air assist is a must when you get into high power. It helps reduce charring on materials and is an important safety measure to reduce emergencies.

The Atomstack air assist system consists of two parts: the air compressor and the air nozzle.

The air compressor is a nice design with two compressors inside. The speed is variable, so if you have finer material, you have the ability to lower the airflow so the material is blown away.

Air enters the laser module from the compressor through a flexible tube attached to the top of the laser module. The air then collects through the interior of the module and exits through the nozzles at the bottom.

Other companies already offer add-on kits for their air compressor systems, but Atomstack is the best and most efficient to integrate it directly into the overall design.

Another improvement is how the laser is focused. The S20 has a focus bracket on top of the material. To focus, you lower the bottom of the laser module until it touches the bracket, locking it in place and removing it from the material.

If the protective lens on the bottom of the laser module is removed, the stand can be flipped over to its side and used for focusing.

So let's talk about the headline feature of this machine, the 20W laser diode. This is the most powerful laser diode you can buy right now.

A single laser diode can't exceed 6 watts, so how do they get to 20 watts? This is achieved by combining four diodes that focus into a single beam. This is similar to a 10 watt module that combines two diodes to achieve its wattage.

It would be really interesting to see when adding laser diodes doesn't make sense. We now have four laser diodes, so the next iteration of this machine could see eight, which brings us to 40 watts.

But even at 20 watts, I found that this machine can cut out a lot of material. Unless you're working with very thin materials, I've recommended engraving primarily with diode lasers in the past. But at 20 watts, you can start cutting without making multiple cuts.