Knowledge
Practical LightBurn guides, settings, testing workflows and troubleshooting — written for real workshop use.
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170 articles
Recovering a LightBurn project from Auto-save
Find the correct backup, preserve it before opening, and understand what Auto-save can and cannot protect.
LightBurn version, license, and operating-system compatibility
Separate three commonly confused questions before installing: can the computer run it, can the license activate it, and can the workshop safely adopt it?
A safe LightBurn update workflow
Back up the right data, install an official update, and verify the workshop setup before returning to production.
Five-Minute Production Preflight
A short standardized preflight catches more failures than improvising settings at the machine: device, units, layers, Preview, material/focus, Frame and physical safety.
Missing Fonts and Portable LightBurn Projects
Live text depends on installed fonts. Moving a project to another computer can substitute/miss fonts unless the same font exists or text is converted to paths when appropriate.
Fill Missing? Check for Open Paths
Fill requires closed boundaries. A visually almost-closed vector can still be open by a tiny gap and therefore not fill as expected.
Double Lines and Unexpected Double Cuts
Duplicate geometry can come from imports, overlapping shapes, stroked artwork converted to outlines or repeated layers. Preview is the fastest way to confirm repeated toolpaths.
Imported Artwork Has the Wrong Physical Size
Wrong import size is commonly a units/DPI/vector-format interpretation issue, not a steps/mm calibration problem.
Laser Output Stays On or Fires Unexpectedly
Unexpected continuous firing is a safety-critical symptom involving output mode, PWM/TTL wiring, controller state or hardware failure. Stop operation before diagnosis.
Laser Moves but Does Not Fire
Motion with no output can be software-layer Output state, S-value scaling, M3/M4/$32/device type, interlocks, power supply, enable wiring or laser-module hardware.
Intermittent USB Disconnects During a Job
Random disconnects can be caused by cable quality, EMI, grounding/power problems, USB power management, hubs or controller resets. The timing and Console log are diagnostic evidence.
“Connecting…” and “Port opened…”: Host Messages vs Controller Output
Messages such as “Connecting…” are generated by LightBurn/host logic, not GRBL. They describe connection progress and should not be decoded as firmware errors.
Full-Wrap Rotary Engraving: Managing the Seam
A full wrap must close geometrically and physically after one circumference; scale error, object taper, slip and start-position error accumulate at the seam.
Rotary Y-Axis Soft Limits and ALARM:2
A Y-axis rotary can command more virtual Y travel than the flat-bed `$131` limit permits, causing ALARM:2 even though the rotary physically has no flat Y boundary.
Rotary Diameter, Circumference and Scale Errors
A wrong diameter/circumference/steps relationship stretches or compresses output around the object. Measure the relevant physical diameter and verify with a known-size test.
Rotary Setup: Chuck vs Roller and What Changes
Roller and chuck rotaries translate motor motion to surface travel differently. Correct setup depends on rotary mechanics, object diameter/circumference and controller axis configuration.
Camera Not Available: Windows Permissions and Device Access
When LightBurn cannot see a camera, the problem may be operating-system privacy permissions, another app holding the camera, drivers or USB bandwidth — not calibration.
Camera Overlay Shift: Fast Diagnosis
Overlay errors can come from stale capture, mechanical movement, incorrect calibration/alignment or material height differences. Pattern matters: uniform shift differs from nonlinear distortion.
Camera Alignment: Map the View to the Laser Bed
Camera alignment establishes the relationship between the corrected camera image and real workspace coordinates; hardware movement can invalidate that relationship.
Camera Lens Calibration: Distortion Before Alignment
Lens calibration corrects optical distortion; alignment maps the corrected camera view to the laser workspace. They solve different problems and should not be treated as one calibration.
Multi-Camera Workflow in LightBurn 2.1
LightBurn 2.1 expands camera support, including multi-camera workflows and a redesigned setup/control experience; each camera still needs correct lens/alignment context.
GRBL $#: laser work coordinates and saved positions
Read G54–G59, G28/G30 and G92 reports in a laser workflow without treating CNC-only PRB/TLO data as a LaserLearn feature.
GRBL $G: Reading the Parser State
`$G` reports the controller’s active G-code modal state and is useful when a line behaves differently than expected because of inherited units, distance or motion modes.
G-code Preflight Before You Trust a File
A preflight should establish units, distance mode, motion/laser state, bounds, feed/power context, unsupported commands and machine-specific assumptions before execution.