What does air assist do on a laser engraver?

It blows a stream of air at the point where the beam meets the material, clearing smoke from the beam path, reducing flare-ups and charring, and pushing burnt material out of the cut. On diode lasers it often decides whether a cut goes all the way through.

Air assist is one of the least expensive additions to a laser and one of the most noticeable in the results.

What happens without it

Smoke rises through the beam and absorbs part of its power. Burnt material stays in the cut. Flames can start in the kerf, leaving wide, charred edges. On a diode laser, which has less power to spare, a cut that would go through with air often stops partway.

What air assist changes

A clearer beam path, so more power reaches the material. Cleaner edges with less charring. Fewer flare-ups, because the airflow cools and removes burning material. Deeper cuts in the same number of passes, which makers often cite in their cutting claims.

The figures to read

Airflow, in litres per minute, describes how much air moves; pressure describes how hard it pushes. The nozzle fit to the laser head, flow control, noise and tubing length complete the list.

What air assist does not replace

Air assist is not extraction. The smoke it moves away from the cut still needs an exhaust or a filter, as the laser maker describes. It also does not make leaving a laser unattended acceptable; supervision advice from the maker still applies.

If this page and the manufacturer’s manual disagree, follow the manual. Every laser power, speed, build volume, resolution, temperature and safety rating on this page is taken from the maker’s own documentation, with its unit as published and its source named — none of it is measured here. A figure is written the way the maker states it and is not converted into another convention, because the converted value would be a different number. And the point repeated rather than assumed: a laser module’s electrical power and its optical power are two different figures. The first is what the module draws; the second is what leaves the lens and reaches the material, and it is smaller. This page says which figure the maker publishes and never presents one as the other.