Laser not cutting through: checks before another run

Record the failed job before changing it

Write down the machine and module, material label, thickness, layer mode, speed unit, power and pass count. Keep the project file and the manufacturer's recommendation together. Add a photo of the result for your own notes. Record whether the failure covers the whole path or appears only at corners.

This is CutChart's troubleshooting record format. It helps you explain the problem without losing the starting conditions. If you are unsure what the machine can process, start with what each laser can cut or mark.

Check both halves of the speed unit

LightBurn's GRBL troubleshooting page warns about confusing millimeters per minute with millimeters per second. Keep distance and time units beside the value when copying a recommendation. Use the speed converter to check the arithmetic before entering it.

Do not change the source note to match the software display. Record the original value and the converted value separately so you can trace a copying mistake.

Follow the branch for your controller

For GRBL: LightBurn identifies two causes of low output: requesting a speed the machine cannot reach in Variable Power mode, and an S-Value Max that does not match the firmware. Follow the GRBL-specific checks with the device manual open. Do not copy another machine's firmware value.

For DSP: At low speeds, the controller may use Min Power. LightBurn explains this in its low-speed power guide. Read the machine's limits before changing either power setting. The GRBL and DSP explanations apply to different controllers.

Match the hardware and material documents

Use the manufacturer manual's focus, optics, air-assist and maintenance checks for your exact configuration. This page cannot determine equipment condition remotely. For acrylic, record whether the sheet is cast or extruded; keep the supplier's material identity with the job.

The optical-watt decoder separates documented emitted power from machine input power. It cannot diagnose a damaged module or measure the output of your own laser.

Keep the correction with the preset

After resolving a documented mismatch, record what changed and which instruction supported the change. The LightBurn library guide explains how to save and organize presets for separate machines.

Follow LightBurn's safety warning and the device instructions; stay with the machine while it operates. A software checklist does not replace a material safety check or a machine inspection.