Overview
When using the LX2’s 455 nm 20 W/40 W/60 W Laser Module, the material’s surface or edges may appear yellowed, blackened, or charred instead of achieving a clean result.
Follow the steps below to diagnose the issue and improve cutting or engraving outcomes.
Possible Causes
- Material incompatibility
- Incorrect focal distance
- Incorrect processing parameters (e.g., power, speed, number of passes, "lower the focus")
- Dirty or damaged protective lens
- Air assist not used or improperly set
- Cutting slats not used
- Laser Module malfunction
Troubleshooting Steps
1. Check Material Compatibility
The 455 nm Laser Module is not suitable for cutting or engraving:
- Transparent materials (e.g., clear acrylic, glass)
- Mirror-finish surfaces (e.g., mirrored acrylic)
- Materials with white surfaces (reflect 455 nm laser light)
Attempting to process these materials may lead to poor results or safety hazards.
2. Check Focal Distance
Incorrect focal distance can enlarge the laser spot, reduce cutting efficiency, and cause charring.
(1) Auto-measure: Click the Auto Measure button in LDS to let the machine measure the focal distance automatically.
(2) Manual measurement: Move the laser module above the material. Use a ruler to measure the distance from the material surface to the bottom of the laser module, and enter the value in the Distance box.
(3) Retry processing after confirming the focal distance.
3. Check Processing Parameters
Incorrect settings are a common cause of charring.
(1) Use recommended settings:
Check the material type and use parameters from the Material Library if available.
(2) Manual adjustment (if no recommended parameters are listed):
Charring often indicates the laser is moving too slowly or dwelling too long. Adjust as follows:
Increase speed:
- Cutting: +1 mm/s per attempt
- Engraving: +10 mm/s per attempt
Reduce power:
- Cutting: −2% per attempt
- Engraving: −5% per attempt
Reduce the number of passes (if multiple passes are used)
Lower the Focus (Cut mode only): For materials thicker than 6 mm, set the lowering distance to 3 mm and perform a test cut. See guide: Lower the Focus of LX2
(3) Test on known materials:
Cut a material that is easy to process (e.g., basswood plywood or kraft paper) using recommended settings. If the cut is clean, the issue likely relates to the original material or parameters.
4. Check the Protective Lens
A dirty or damaged lens can scatter the laser beam, reduce power density, and cause charring.
(1) Power off the machine before inspection.
(2) Clean the lens: If dirty, follow the tutorial Clean the LX2 Air Nozzle & Protective Lens.
(3) Replace the lens: If damaged (burn marks, cracks, or irreparable damage), replace it with the spare lens included in the LX2 kit.
5. Use Air Assist
Air assist helps prevent yellowing or blackening of edges.
(1) Connect the air assist to the LX2.
(2) Ensure the tube is securely connected and undamaged. Set to manual mode, then feel the airflow carefully (do not place your hand near the nozzle while the laser is operating).
Do not put your hand close to laser module while the laser is operating.
The air assist supports automatic and manual modes. See guide: Using Air Assist with LX2.
6. Use Cutting Slats
Cutting slats improve airflow, reduce heat buildup, enhance smoke extraction, and improve cutting results.
(1) Insert the slats into the front and rear frame slots inside the machine.
(2) Adjust spacing based on your needs. The standard LX2 package includes 4 slats; additional slats can be purchased separately.
7. Potential Laser Module Malfunction
If severe yellowing or blackening persists after following all steps, even on compatible materials with correct settings, the laser module may have an internal issue.
Contact customer service: support@laserpecker.com for assistance.