How to Set Up Laser Engraver Air Assist
Air assist blows a stream of compressed air across the laser focal point. It's one of the highest-impact upgrades for a diode laser engraver — it dramatically improves cut quality, reduces charring, prevents flare-ups, and extends lens life.
Why Air Assist Matters
Without air assist:
- Smoke and combustion products linger at the focal point and absorb laser energy
- Wood and acrylic char and flame more
- Lenses cloud faster from smoke deposits
- Cuts are slower and messier
With air assist:
- Smoke is blown away instantly — laser hits clean material
- Cut edges are cleaner and less charred
- Acrylic cuts with polished-looking edges
- Less chance of material catching fire
- You can often cut faster or with fewer passes
Air Assist on the Ray5 20W
The Longer Ray5 20W has a built-in air assist port on the laser head. It uses a 3-pin connector (power + signal) that controls the pump via the controller.
The air pump connects to the dedicated port — not USB, not the emergency stop port. The pump runs when the laser fires.
Wiring order when reconnecting (critical):
- Power cable first (red connector)
- Signal/PWM cable second
- Air assist connector third
See the machine reference note for full reconnection procedure.
Air Pressure and Flow
For diode laser engravers, the stock air pump is generally sufficient. For upgraded cutting performance, a stronger aquarium pump or small air compressor gives better results.
| Application | Pressure | Notes |
|---|---|---|
| Wood engraving | Low (stock pump) | Enough to clear smoke |
| Wood cutting | Medium | Prevents charring, enables single pass |
| Acrylic cutting | Medium-high | Critical for polished edges |
| Leather | Low | Too much air blows material |
| Thin paper | Off or very low | Air displaces material |
DIY Air Assist Upgrade
If your laser doesn't have built-in air assist:
- Mount a nozzle bracket to the laser head (print one or buy universal kits)
- Run 4-6mm OD tubing from a small aquarium pump or compressor
- Aim the nozzle at 30-45° to the focal point — not straight down
- Connect pump power to a power strip you control, or wire to a spare output on your controller
Aquarium pump (e.g., Hygger 60L/min): ~$15, runs quietly, enough for most diode lasers.
LightBurn Settings
For machines with controllable air assist:
- Edit → Device Settings → Enable air assist output
- In Cut Settings for each layer: check Air Assist On
- Toggle per-layer — you might want air on for cuts but not engraving dark wood
Nozzle Maintenance
- Check nozzle alignment monthly — bumps during use can shift the angle
- Clean the nozzle tip with a cotton swab if residue builds up
- Ensure the air tube isn't kinked — restricted airflow defeats the purpose
- Replace the foam filter on pump inlets every few months
Troubleshooting
Air not blowing during cuts — check the pump power connection, check the controller air output signal, verify LightBurn air assist is enabled for the layer.
Cut quality not improving — check nozzle is aimed at the focal spot, not above or to the side. The air jet should hit exactly where the laser hits the material.
Material lifting during cutting — air pressure too high for the material. Reduce flow or angle the nozzle more shallowly.