Air assist on the k40 laser machine

This article will help you optimize your air flow settings for your machine.

What is air assist?

Air assist is the help of a air stream keeping the cut or engraving clean from debris and smoke.
The laser beam works similar to your headlights on the car, too much fog and the visibility goes down. Same with the laser, too much smoke or other obstacles the power will go down and the quality with it.

When should i use air assist?

When you are cutting?
Cutting through materials a air assist helps you keeping the cut clean.

When you are engraving?
The air assist just push the smoke back to the material, Here is a Smoke assist better to use, preventing the fumes destroying the work.

This article was written in it´s first version 2015. At this time there was only a few laser heads available. Since then there has been a few better ones released that actually works pretty good.

Usual misconception about air assist

On many groups and forums the air assist is the same as a nozzle, like this one.

This text has been edited and shortened.
When this was written in 2015 the laser head in the picture above was one of few heads on the market. And it was really bad causing the head acting like a vacuum cleaner, pushing air out in the bottom and sucking smoke in at the top creating optic damages and a lot of cleaning.
Since then it has been released a lot more heads on the market, so this text has been deleted about this nozzle due to this.

How you hook up good working air assist

Add a 4-6mm air hose to a compressor, can be anything from a small fish tank airator to a 50L/min small pump.
If you want to cut wood or do a lot of engraving, a bit more flow is needed.
On the end of the hose, add a metal or plastic pipe you can bend. (i use 4mm brake lines).
Aim the pipe to where the cut hits.
This solution has more airflow in a single jet than the nozzles can produce with the same pump.

Picture of my air assist

Why this works

Try this, put your hand 5″ in front of your mouth – blow
Now try the same thing with a straw, blow the same you did before.
The laser beam is about 0.2mm thick, wich type of blow do you think is most effective? 😉

Using a small fish tank air pump you can get away with  $20 for pump, hose and connectors needed. And when the pump is running the sound level isn´t higher than your computer.The only air assist nozzle i approve
Since this article was written i have been busy testing a bunch of air assist laser head combos, and found one that actually works.

This laser head is not perfect, but can be modded to perfection. With a movable neck you can set the proper height and focus of your machine with the twist of your hand.
Easy to set proper focus, good protection for the lens and a fairly good mirror holder.
Read this article how to upgrade this type of laser head

Using a air assist nozzle can have good results when engraving wood, i would rather suggest you optimize a smoke assist system in your machine than buying a nozzle