

If you have “bitten the bullet” and gone out and bought yourself a K40 laser, you will know it’s a good machine. One thing I want to talk about In this post though it the k40 air assist, which will turn your K40 from a rough blue box, to an engraving beast.
I mean for the price it’s a beast without the air assist. Being new to the market before I purchased my k40 I wasn’t expecting much.
I Shot over the Amazon, Paid my money and crossed my fingers that the thing would actually arrive and in actually fire up first go.I was nervous to be honest, which i why I didn’t cut any corners and purchased a k40 laser assist
I had only read a few reviews before purchasing my K40, and one of the things I was concerned with was the fact that the stock K40 didn’t come with an air assist.
Because I live in a residential unit with little to no space to actually use my K40, I was nervous that the K40 would be a fire hazard without a K40 air assist.
Here is a short run-down on my experience with adding a K40 air assist to the K40 arsenal
The best option for the k40 Laser Engraver
Engraving by hand is a long a laborious process, and, in today’s fast-paced production environment, the process takes far too long. With the advent of over-the-counter laser engraving machines—such as the trusty K40—anyone can be a master engraver.
The artistry that comes to life with these machines is spectacular. What’s more, they produce superior work with consistent design quality. Lookout, Etsy? Here we come!
Other than the initial cost, there are a few hurdles that will present themselves during operation.
The K40 machine is a 40-watt laser engraver. It is considered one of the most basic and affordable laser engravers on the market, not to mention one of the first machines produced for private use.
This series is a rock-steady engraver, but that doesn’t mean that there are any flaws in the design. This post seeks to answer some of those questions by highlighting a few significant problems and point you in the right direction of an easy fix for many of the operating issues you may come across when using your K40 Laser Cutter with or without an air assist.
What are the Risks of Engraving without a K40 Air Assist?

- Smoke can impede the laser: Laser engravers literally use high-intensity lasers to burn through/into whatever material you are engraving. When things like wood burn, they produce quite a bit of smoke. All other materials will produce something like smoke, which is actually a fume comprised of extremely fine particles.
This smoke or fumes will impede the laser during it’s cutting by not only obstructing the beam but will eventually build up on the lens of the laser.
Imagine lighting a candle under a low ceiling or a fire in the fireplace. In each instance, soot will inevitably build-up on the surface directly above it.
In this case, tiny particle matter produced during the engraving process will build-up on the lens, eventually obstructing the beam from traveling through the lens.
The smoke/fume may also simply float through the beam of the laser, thus making it less effective. - Debris may cause the laser to make less accurate cuts:
Larger particles or debris created during the engraving process may build up around the engraving site, especially when doing incredibly intricate work. The debris that collects around the edges of the design will inevitably obstruct the path of the laser, thus making your cuts less accurate, resulting in engravings that appear fuzzy or otherwise unclear. - Fires can start if the engraving surface is not continuously cleared:
As previously stated, laser engravers use an immense amount of heat to engrave through/into any material. This heat not only creates smoke, but it also has the potential of starting a fire in your workstation. Gases are releases when engraving certain materials may have the potential to ignite.
While this is unlikely, the possibility remains. The more likely scenario is one in which the engraving surface has become cluttered with debris. When the laser passes over larger pockets of debris, the risk of fire rises dramatically, especially when engraving on wooden or other flammable surfaces.
Have you ever found yourself experiencing any of these problems? If so, then you’re definitely not alone. If you’d like to learn how to avoid these in the future, keep reading.
What can I do to eliminate these hazards?

If you’ve ever worked with a laser engraving machine, then you know that cleanliness is of the utmost importance. Stopping work habitually to clear the engraving surface or change the lens on your laser can be incredibly frustrating.
These things slow down efficiency and production and create added stress. Along with stress and added effort, there is a financial cost incurred by these difficulties. But, these issues are easily avoided. How may you ask? The simple answer is that you can install an air assist.
Chances are, if you’re reading this blog, you probably already have some familiarity with air assist technology. At the very least, you’ve heard of it. However, some of us may be new to the world of laser engraving. If you’re asking yourself, “What the heck even is an air assist?” Then you’ve come to the right place.
You may have also heard of a couple of other different devices that all have “air” in the name. This stuff can get confusing. For instance, there’s exhaust air that pulls air out of the case.
There’s cooling air that blows air on parts of the machine that get hot. You’ve probably also heard of intake air that pulls fresh into the case. And, purge air that refers to another device that specifically evacuates smoke and other potentially harmful fumes away from the laser lens. All of these are topics for other posts.
The term air assist typically refers to an attachment to a standard laser engraver that provides a steady flow of air from some type of air compressor that runs through a hose connected to the laser-cutting mount.
For an air assist to function properly, the hose must be small enough to direct a fine stream of air onto the engraving surface at the point where the laser hits. It must be attached to the laser mount directly so that it will continuously feed air the area being burned by the laser.
This focused stream of air will effectively clear the engraving surface of any debris left behind during the cutting process and help to keep smoke/fumes away from the laser’s lens.
An air assist will save you countless hours of cleaning and frustration. Attaching one of these mechanisms will also give you far superior results on a wider variety of materials. Without an air assist, you can expect an approximately four percent diminished output every ten minutes until the laser is rendered nearly ineffective. Eventually, the lens will begin to heat up from the amount of energy dispersed across its surface.
If not cleaned regularly, you run the risk of the lens shattering during the engraving process, which will, in turn, delay work even more and cost even more money. To put this simply, an air assist will nearly eliminate all three of the problems mentioned in the previous section.
How do I install my air assist?

The first and most obvious way to install an air assist into your K40 laser engraver would be to purchase a premade nozzle for your laser lens with a built air assist port from a manufacturer. With these nozzles, you can simply get a small air compressor and the correct-sized flexible hose that will attach directly to the air intake port on the side of your new nozzle. However, the nozzles from the manufacturer are often more trouble than they’re worth and here’s why:– For it to work correctly, you’ll need higher airflow and pressure.
– More than likely, you’ll be forced to buy an oversized, noisy, and often expensive compressor to get the correct pressure.
– These nozzles do not direct the air in a concentrated stream, so the air goes all over the place rather than in a nice small stream.
– The venturi effect makes the nozzle a vacuum cleaner, pulling smoke in above, dirtying your lens faster.
– You will inevitably spend more time and money in changing your lens or cleaning it.
These nozzles, at first glance, sound like the perfect buy. They’re easy to purchase, easy to install, and easy to use, but after much trial and error, it’s easy to conclude that they aren’t very well-made and end up costing you more time and money in the long-run.
Another major flaw found in standard nozzles is that they do not bring the airflow down low enough. To ensure that your air assist is most effective, make to set the end of your airflow to the correct height is approximately 5mm above the engraving surface. The fact that most manufactured nozzles do not come down this far makes them far less effective.
With all that said, there are many different types of nozzles. Not all nozzles are made the same. If you’re willing to spend the time and money to find one that works best for you, and you have a gigantic air compressor already that can produce the needed pressure to blow hard enough to be effective, then go for it. However, if you’re ballin’ on a budget, and prefer to have a solution that is not only cheaper but will save space in your shop and will be more effective, then keep reading.
Using the K40 as a model, hooking up a cost-effective means of distributing air to where you needed is both cheap and easy.
Required materials for complete K40 air assist:
- A small compressor or even a fish tank aerator.
- 4-6mm hose
- A small piece of flexible piping (metal or plastic)
- Zip ties or other connectors
To set this up, you will connect your hose to the laser cutting arm with the zip ties, making certain that the hose is secure and does not hang down away from the cutting mechanism. You may need several zip ties for this. Use the small piece of flexible piping to create a nozzle for the hose that can be bent and directed into the cutting path.
To cut through wood or when doing a LOT of engraving, you will want to upgrade your compressor. For these tougher materials, you will need a larger model that can support more BTUs to ensure that the engraving surface is clear of excess debris. You will also want to make certain that your airflow is strong enough to push smoke away from the laser lens.
Some articles will argue to use a much larger hose but, remember, the smaller the diameter of the hose, the more focused the air stream. Focusing the stream through a smaller tube will allow you to have a smaller air compressor. To illustrate the point, hold your hand about six inches away from your mouth and blow. You may feel some air pressure. Now put a straw in your mouth and blow. Not only does this bring the air output closer to your palm, but it also creates a much tighter stream, and you will notice that it is a more concentrated burst that can be targeted more precisely.
All-in-all, this method is the cheapest, most effective way to add an air assist to your K40 laser engraver. If you aren’t running a massive engraving operation and can get away with using a small fish tank air pump, you can really save yourself in cost. The sum total, for all the necessary parts, is about $20. Moreover, while running, the pump is not any louder than your desktop computer.
While this article focuses on the K40 model of laser engravers, an air assist is still necessary for higher-end models such as the Glowforge. However, these higher-end models have a much higher price tag because they’re worth it. In the beginning, Glowforge had not included an air assist in order to keep costs down; however, they have since found ways to combine the air assist and purge air to keep costs down.

No matter what machine you’re working on, the best advice that I’ve come across would be to stay adaptable. If you’re willing to tinker, you can make some very simple modifications to a cheaper model and increase functionality greatly. When shopping around for a laser engraving machine, you should consider the size of the case, the size/power of the fan, and make certain that you have room to install an air assist to keep the engraving surface clear of debris and keep the lens clear of any smoke/fume.
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