Guide · November 8, 2026
LightBurn Setup for Diode Lasers: First Connection to First Job
How to connect a GRBL diode laser to LightBurn, match the power scale, set the origin, run a material test and avoid the setup mistakes that cost beginners power.
LightBurn is the layout, editing and control program most diode laser owners end up using. It drives most brands from one interface, has a proper material test tool, and handles layers, fills and cut order better than most free brand software.
This guide covers the setup most people get wrong on day one.
Before you start
- Install the machine’s USB driver if the manual asks for one.
- Update the machine firmware only if the manufacturer recommends it.
- Download LightBurn from the official site. The trial runs fully featured.
- Connect the laser by USB and power it on.
Step 1: Add the device
Open LightBurn and go to the Devices panel.
- Click Find My Laser. LightBurn scans the USB ports.
- Most open-frame diode machines, including Atomstack, Sculpfun, Ortur and Longer, run GRBL firmware. Pick the GRBL device type.
- If auto-detect fails, add the device manually. Choose GRBL, then USB/serial.
- Enter the work area exactly as the manufacturer specifies, in millimetres.
- Set the origin to the corner where your machine homes. This varies by brand, so check the manual.
Step 2: Match the power scale
This is the step that silently costs beginners power.
GRBL firmware has a setting called $30, the maximum spindle value. It tells the machine what number means “100% power”. LightBurn has a matching S-value max in the device settings.
- In LightBurn, open Console and type
$$, then press Enter. - Find the line that starts with
$30=. It is usually 1000. - Open Edit → Device Settings and set S-value max to the same number.
While you are in the console output, check that $32=1. That enables laser mode, which turns the beam off during moves between shapes instead of leaving burn marks.
Step 3: Set up the cut settings
Each colour layer in LightBurn has its own settings. The main ones:
| Setting | What it does |
|---|---|
| Mode | Line (follow the path: cuts, outlines), Fill (raster engrave the inside) or Image |
| Speed | mm/min. Higher means lighter marks |
| Max power | Percentage of full power |
| Passes | How many times to repeat |
| Interval / lines per inch | Spacing between fill lines; finer spacing means darker, slower fills |
| Air assist | On for cuts, usually off or low for engraving |
Our settings charts give starting values for each machine and material.
Step 4: Run a material test
Open Laser Tools → Material Test. Set power on one axis and speed on the other, choose small squares and run it on a scrap of your material. Pick the square you like and copy its values into your layer.
The focus and test grid guide explains how to read the result.
Step 5: Frame before every job
Use the Frame button to trace the outline of the job with the laser off or at a low pointer power. It shows exactly where the job will land on the material. Combined with the Start From setting, it is how you place a design accurately.
Start From options in plain terms
- Absolute coords: the job goes where it sits on LightBurn’s grid. Needs a homed machine.
- Current position: the job starts wherever the laser head is now.
- User origin: like current position, but you set a reusable starting point.
Most beginners find Current position easiest at first.
Optional: camera alignment
A camera module lets you see the material on screen and drop designs onto it. LightBurn needs a one-off lens calibration and alignment. Follow the wizard carefully; a bad alignment makes the camera less accurate than framing.
Common first-week problems
- Laser weak or barely marking: check S-value max matches $30.
- Burn lines between shapes: laser mode is off; set $32=1.
- Job mirrored or in the wrong corner: the origin is set wrong.
- Job runs off the edge: the work area size is wrong.
When everything is set, save a backup of your device profile and library so you can restore it after a reinstall.