Two lines can look like one on the Workspace while the laser traverses the same edge twice. This overheats the edge, wastes time and can create a fire risk. The cause may be an exact duplicate, overlapping parts, or an import built from stacked shapes.
Diagnose before changing geometry
- Save a copy of the project.
- Select the suspect objects and open Preview.
- Enable travel-move display and step through the job. Watch whether the same edge is processed twice.
- Temporarily assign the suspect objects to one distinct Line layer. This makes the test easier to interpret.
The expected result is one processing pass per intended edge. A darker Preview line alone is not proof; use the playback/order and estimated path.
Exact duplicates versus overlaps
Use Edit → Delete Duplicates for identical objects occupying the same coordinates. Rerun Preview. If the duplicate disappears and the visible design remains unchanged, you found exact copies.
Shared borders between separate parts are different. If both parts must remain editable, use the Line layer's Remove Overlapping Lines option in the Cut Settings editor for the output copy. This suppresses coincident output segments while preserving the design objects. The exact location can vary by LightBurn version; open the Line layer and use F1 over the option for the matching official reference.
