Are you searching for an Air Assist for lasers? Are you wondering if an Air Assist is even necessary for your laser? In this article, I will answer all your questions about Air Assist for lasers and compare three different types of pumps: a Hailea aquarium pump, the Sculpfun Air Assist, and a whisper compressor commonly used in workshops.
What Are the Benefits of an Air Assist?
During laser cutting and engraving, the material at the laser’s focal point burns at temperatures reaching up to 1,000°C. This heat is so intense that the material sublimates, transitioning directly from solid to gas. An Air Assist blows compressed air through the nozzle directly into the focal point. The compressed air has four main functions:
- Oxygen Supply: Compressed air delivers additional oxygen to the focal point, enhancing combustion. This has several advantages: it reduces smoke by enabling cleaner combustion, increases efficiency, and allows cutting through materials at higher speeds.
- Smoke Removal: The air stream pushes smoke through the cut and away from the workpiece. This prevents smoke from settling on the workpiece and leaving scorch marks.
- Lens Protection: The airflow protects the focusing lens in two ways. It prevents smoke from rising and settling on the lens and cools the lens simultaneously. Therefore, even during engraving, a small airflow should always be present.
- Prevents Flame Formation: The strong airflow extinguishes any flames that may arise
What to Consider When Using an Air Assist for lasers?
An Air Assist is a pump that generates compressed air. This air is delivered through a hose system directly to the laser’s nozzle, where it flows into the focal point. The amount of air the pump can produce is crucial. For laser cutting, the rule is simple: the more air, the better!
For engraving, however, the opposite is true: minimal airflow is needed. Too much air could push smoke back onto the workpiece, leaving scorch marks. Still, a small airflow should always be present to prevent smoke from rising to the lens and to cool it. Cooling is critical because a small amount of energy is always lost in the lens, causing it to heat up. If the lens is dirty, laser burns can embed deposits into it, causing it to crack.
To ensure an adequate airflow reaches the nozzle, the hose diameter should be at least 6 mm internally.
Laser Air Assist with a Pond Pump?
Using pond pumps as Air Assists for lasers is very popular. Chinese CO₂ lasers (e.g., Omtech*, Vevor*, etc.) typically include pond pumps of various sizes as part of their package. Beginners often choose small membrane pumps with 60 L/min output, such as the Hailea ACO-318 (Amazon*), due to their affordability. I initially used a Hailea ACO-318 with my first CO₂ laser but was only moderately satisfied. Scorch marks were reduced but still quite visible. Larger pond pumps with 140–280 L/min output, such as the Hailea ACO-500 (Amazon*), cost about five times more but still fail to eliminate scorch marks completely.
One significant downside of these pond pumps is their pulsed airflow, which can lead to uneven cutting results, depending on the speed. Another disadvantage is the lack of airflow adjustment, meaning you can’t switch between a strong airflow for cutting and a light breeze for engraving.
I do not recommend Hailea ACO pumps. They are loud, non-adjustable, and deliver only minimal performance. While they reduce scorch marks to some extent, they cannot eliminate them entirely. The only exception: if you are on an extremely tight budget, they are better than no Air Assist at all for a K40 or K50 CO₂ laser.
How Good Is the Sculpfun Air Assist?
The Sculpfun Air Assist (Amazon*) is popular for diode lasers. While it delivers only 30 L/min, it features an adjustable airflow knob. This allows you to differentiate between maximum airflow for cutting and minimal airflow for engraving. The Sculpfun Air Assist is also significantly quieter than Hailea pond pumps. While noise may not matter in a workshop, a loud pump can be very annoying if you’re operating your laser at home.
The Sculpfun Air Assist provides decent results, visibly reducing scorch marks. It’s ideal for engraving since you can regulate the airflow. However, it’s not suitable for frequent cutting tasks.
I recommend the Sculpfun Air Assist (Amazon*) for use with small diode lasers up to 40W for engraving and occasional cutting. It costs slightly more than the small Hailea ACO-318 (Amazon*) but offers a quieter, compact Air Assist with adjustable airflow.
Air Assist Compressor with Storage Tank
A proper Air Assist requires a lot of air—really, a lot of air! But the reward is scorch-free cuts. Check out all tips for avoiding scorch marks in this article: Avoiding Smoke Marks in Laser Engraving – Tips for Laser Cutting and Laser Engraving on Wood.
Workshop compressors with storage tanks are excellent for providing a continuous airflow and sufficient pressure. For scorch-free cuts, 1–2 bar pressure is ideal. To ensure sufficient airflow, the hose should have an internal diameter of at least 6 mm, preferably 9 mm.
Oil-free twin-cylinder whisper compressors (Amazon*) with a 50 L tank have proven effective for Air Assist. A 50 L tank is the minimum since the compressor must constantly produce air during cutting tasks. These compressors are not designed for continuous operation and require regular breaks to prevent overheating. Additionally, make sure to use a water separator to avoid condensation on the lens.
Another advantage of these compressors is their versatility—they can be used for other tasks, such as airbrushing, operating pneumatic tools (e.g., orbital sanders), and inflating car tires. I recommend using a compressor as an Air Assist for CO₂ lasers with 50W or more.
Conclusion
An Air Assist is essential for every laser! Operating a laser without Air Assist is dangerous, as it effectively prevents flames from forming at the focal point and improves combustion. Here’s a summary of the key features from this article:
| | Hailea ACO-318 (Amazon*) | Sculpfun Air Assist (Amazon*) | Compressor with Storage Tank (Amazon*) |
|---|---|---|---|
| Advantages | – Affordable – Easy to install | – Adjustable airflow – Affordable – Quiet | – Scorch-free cuts – Adjustable pressure – Versatile for other tasks |
| Disadvantages | – Loud – Non-adjustable | – Low airflow | – Expensive – Large – Not truly quiet |
| Recommendation | Not recommended | – Engraving – CO₂ and diode lasers up to 40W | CO₂ lasers 50W and above |
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