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LightBurn Setup Guide for Diode Lasers (2026)

LightBurn Core ($99 one-time as of mid-2026, 30-day free trial) connects to your GRBL-based diode laser in about 15 minutes. Three GRBL firmware parameters — $32=1, $30=1000, and $13=0 — fix the vast majority of first-time setup problems. This guide covers all five setup steps and the GRBL parameter reference you'll paste into the Console. Last verified: 2026-07-02 — lasertinkerer.com

Key findings
  • Three GRBL parameters fix 90%+ of first-time problems: $32=1 · $30=1000 · $13=0
  • $32=1 (laser mode) is the single most important setting — without it, images stutter and burn unevenly
  • S-Value Max in LightBurn Device Settings must match $30 in firmware (both 1000)
  • GRBL firmware must be version 1.1f or later for laser mode to work — check the Console startup message
  • Some xTool models require xTool Creative Space instead of LightBurn — test with the 30-day trial first
LightBurn first-time setup flow STEP 1 STEP 2 STEP 3 ★ STEP 4 STEP 5 Download & Install Add Device (Find My Laser) $32=1 $30=1000 $13=0 S-Value Max = 1000 Test Grid & First Cut
Step 3 (GRBL parameters) is where most first-time problems live — it takes 30 seconds and fixes almost everything.

Step 1 — Download and Install LightBurn

Download the installer for your operating system from lightburnsoftware.com. LightBurn runs on Windows, macOS, and Linux. The 30-day free trial is fully featured — no limitations, no watermarks. You do not need a license key to start using it.

The license you need for most diode lasers is the LightBurn Core license ($99 one-time, as of mid-2026). It covers all GRBL-based machines from xTool, Sculpfun, Ortur, Atomstack, and similar brands. Do not buy the LightBurn Pro license — that is for CO₂ machines with DSP/Galvo controllers. Software updates for the first year are included; renewals are optional at $40/year after that.

xTool compatibility note: Most xTool machines work with LightBurn via GRBL. Some newer models (especially those with proprietary xTool protocols) officially require xTool Creative Space. The 30-day trial will tell you immediately — if LightBurn connects and jogs your machine, you're compatible.

Step 2 — Add Your Device

When you first open LightBurn, it asks you to add a device. You can do this at any time from the Laser panel → Devices button.

  1. Click Find My Laser — LightBurn scans USB ports and identifies connected GRBL machines automatically. This works for most machines.
  2. If auto-detect fails (or you want to set dimensions manually), click Create Manually → GRBL.
  3. Enter your machine's work area in mm. Common sizes: 400 × 400 mm (most 10W class), 430 × 430 mm (Sculpfun S30), 500 × 500 mm (some Atomstack). Check your manual.
  4. Set the origin — most diode lasers home to front-left. If your machine homes to a different corner, the "machine origin" setting must match.
  5. Give it a name and click Finish. LightBurn creates a .lbdev profile file you can back up.

Step 3 — Set the Three Critical GRBL Parameters

This is the step most guides skip and the cause of most first-time failures. Open the Console tab in LightBurn (bottom right by default), then type each command and press Enter:

$32=1
$30=1000
$13=0

After each command, GRBL replies with ok. These settings persist in the controller's EEPROM — you only need to do this once per machine. Here is what each does:

GRBL PARAMETER REFERENCE — CRITICAL FOR DIODE LASERS
Parameter Value What it does Without it
$32 1 Enable laser mode — power changes are instantaneous, no mid-move pauses Images burn unevenly; bright spots at every direction change; vector cuts pause
$30 1000 Maximum S-value (spindle/laser PWM range). Must match LightBurn's S-Value Max Laser runs at wrong power — if $30=255 and LightBurn expects 1000, you get 25% max power
$13 0 Report positions in millimetres (not inches) LightBurn position display is 25.4× wrong; homing and soft limits misbehave
$10 0 Position report mode — report work position (not machine position) Optional but recommended; needed if you use G10/G54 workspace offsets

To check your current settings, type $$ in the Console and press Enter. GRBL prints all current parameter values.

To check your GRBL firmware version, look at the startup greeting in the Console when LightBurn first connects. It should say something like Grbl 1.1f ['$' for help]. Laser mode ($32=1) requires GRBL 1.1f or later. If you see an older version, check your manufacturer's site for a firmware update.

Step 4 — Match S-Value Max in LightBurn

Go to Edit → Device Settings (or the gear icon next to your device name). Find S-Value Max and set it to 1000 — this must match the $30=1000 you set in firmware. If they don't match, your power percentages will be wrong.

For example: if $30=255 (an older default) and LightBurn's S-Value Max is 1000, setting 50% power in LightBurn actually sends a signal for 500/1000 — but the machine interprets that as 196%+ of its actual range, which may max out the laser unexpectedly.

The safe path: set both to 1000 and you will never have a power-calibration mismatch.

Step 5 — Framing, Fire Test, and First Cut

Before burning anything, do a framing pass: place your material, load a design, then Shift+click the Frame button (or press Shift+F). This traces the bounding box of your design with the laser off (in LightBurn). Confirm the trace stays within your material and away from edges.

Then test the Fire button: in the Move window (Laser tab), set the power slider to 1–2% and click Fire. The laser dot should appear on the material surface. If nothing happens at this step, your $32 setting or S-Value Max mismatch is usually the cause.

For your first real burn, use the Material Test Grid Generator to create a calibrated power×speed grid for your material. Run it before any project — it saves you wasted material and dialing-in time on every new material you cut or engrave. Confirm with a test square before committing to a project.

Air assist tip: If your machine has an air assist pump, turn it on before every cut. Air assist extends nozzle and lens life, reduces charring, and dramatically improves cut depth on thick materials. On most diode laser controllers, air assist is controlled by the M8 G-code command — LightBurn supports this via a layer option.

Common First-Time Mistakes

Symptom Root cause Fix
Images burn with bright spots or blotches at corners $32=0 — laser mode off. If corners are still darker even with $32=1, see the M4 dynamic power guide. Console: $32=1
Laser does not fire at all at correct power $30/S-Value Max mismatch; fire slider at 0% Set both to 1000; raise fire slider above 0
Position display wrong; machine moves to wrong place $13=1 (inches mode) or wrong origin Console: $13=0; confirm origin matches physical home position
Cuts don't go all the way through Focus off by 1–2 mm; wrong power or pass count Re-focus carefully; run a material test grid first
Machine moves but laser does not fire USB connection dropping; wrong COM port Use a shorter, shielded USB cable; reconnect device; check Device Manager
LightBurn says "connection failed" Wrong baud rate (most GRBL diode lasers use 115200) Edit device, set baud rate to 115200

Frequently Asked Questions

Does LightBurn work with xTool diode lasers?

Most xTool machines work with LightBurn using the GRBL/G-code license. Some newer xTool models use a proprietary protocol and officially require xTool Creative Space. The 30-day trial will tell you immediately — if LightBurn connects and jogs your machine, you're compatible. See our LaserGRBL vs LightBurn guide for the full compatibility picture.

Why does LightBurn not fire the laser?

The most common cause is $32=0 (laser mode disabled). Open the Console and send $32=1. Also check that S-Value Max in Device Settings matches $30 in firmware (both should be 1000). Finally, the Fire button in the Move window requires the power slider set above 0% — it defaults to 0 for safety.

What is $32=1 and why does it matter?

$32=1 enables GRBL laser mode. Without it, the controller pauses briefly at every power change (a safety feature designed for spindle tools). On a laser, those pauses create excessive burn spots on images and stuttering during vector cuts. Laser mode eliminates the pauses because the laser reacts instantly to PWM changes. It requires GRBL 1.1f or later — check the startup message in the Console tab.

How much does LightBurn cost?

LightBurn Core (the license for GRBL/G-code diode lasers) costs $99 as of mid-2026. A 30-day full-featured free trial is available from lightburnsoftware.com. One license installs on up to two computers. The license is perpetual — your current version works forever. Software updates for the first year are included; optional update renewals cost $40/year after that. See our xTool Creative Space vs LightBurn guide if you're deciding whether to buy.

What speed units does LightBurn use?

LightBurn defaults to mm/min for GRBL devices but can display mm/s or in/min. You can change the display unit in Edit → Settings → Units. The settings database on this site publishes both mm/min and mm/s for every row so you can cross-reference regardless of your LightBurn display setting.

Where do I find starting settings for my material?

Use the Material Test Grid Generator to burn a calibrated power×speed grid, then dial in from there. The settings database has sourced starting points for common materials across multiple machine wattages — treat them as starting points, not absolutes. Results vary by batch, focus accuracy, and air assist.

Once LightBurn is set up, the next thing to understand is when to use Fill mode (raster engraving) vs Line mode (vector engraving and cutting). See the raster vs vector guide for the decision table and LightBurn workflow.

Sources: LightBurn official documentation (docs.lightburnsoftware.com/BeginnerAddConfig), LightBurn GRBL configuration guide (docs.lightburnsoftware.com/…/GRBLConfiguration), Diode Laser Wiki setup guide (diode-laser-wiki.com). AI-assisted aggregation and normalisation; settings are starting points, not guarantees. Last verified 2026-06-26.