Common Issues in Laser Cutting and How to Solve Them

Laser cutting is a highly efficient and precise processing method widely used across industries such as automotive, aerospace, construction machinery, and heavy equipment manufacturing. Despite its advantages, even the most advanced laser cutting machines can experience problems that compromise the final product’s quality. Han’s Laser has compiled a comprehensive overview of the most common issues encountered during laser cutting—and more importantly, how to fix them.

Whether you’re operating a compact laser cutter or a large-scale, high-power laser cutting machine, the following insights will help you enhance performance, reduce waste, and ensure consistent cutting results.

1.Rough Edges or Burrs on Cut Surfaces

Symptoms:

Edges appear jagged, rough, or have hanging burrs after cutting.

Causes:

Insufficient laser power: The beam lacks the energy to completely melt through the material.
Cutting speed too fast: The laser moves faster than the material can respond, leaving an incomplete or rough finish.
Incorrect focal length: Misalignment of the laser beam’s focus reduces energy concentration.
Improper assist gas pressure: Low or excessive pressure interferes with slag removal.
Material and parameter mismatch: Using one-size-fits-all settings without adjusting for material type and thickness.
Contaminated laser optics: Dust or residue on the lens or nozzle distorts the beam quality.

Solutions:

Increase the laser power to ensure full material penetration.
Slow down the cutting speed to give the beam more time to process the cut.
Recalibrate the focus so that the focal point lands slightly below the material surface.
Fine-tune the assist gas pressure based on the material being cut.
Adjust cutting parameters according to the material’s specifications.
Regularly clean the lens, nozzle, and mirrors to maintain clean optics.

2.Excessive Melting or Wide Kerf

Symptoms:

The cut line is wider than expected or the material appears to have melted excessively.

Causes:

Laser power too high: Overheating the material causes a broader heat-affected zone.
Cutting speed too slow: Prolonged exposure increases heat accumulation.
Improper focus setting: A defocused beam spreads energy over a larger area.
Low assist gas flow: Insufficient gas fails to blow away molten material.
Material is too thick or poorly conductive: These materials are more prone to excessive heating.
Poor beam quality: An unstable or divergent beam can reduce cutting precision.

Solutions:

Lower the power settings based on the material’s thickness.
Increase the feed rate to reduce dwell time.
Recalibrate the Z-axis or nozzle height for accurate focusing.
Ensure a stable and adequate gas supply.
Choose cutting parameters tailored for thick or difficult materials.
Inspect and maintain the laser source and beam path regularly.

3.Wavy or Uneven Cutting Surfaces

Symptoms:

The cut surface displays ripples or inconsistent finish along the edges.

Causes:

Laser power instability: Fluctuations in output lead to inconsistent material melting.
Inconsistent cutting speed: Speed variations disrupt the smoothness of the cut.
Focus drift: A shifting focal point weakens beam consistency.
Material deformation: Warped or uneven materials change the beam distance.
Mechanical vibrations: Loose components or unstable frames introduce physical shaking.
Irregular gas flow: Inconsistent airflow affects how molten metal is expelled.

Solutions:

Use a stable power supply and ensure consistent power settings.
Maintain uniform cutting speed throughout the operation.
Frequently calibrate the focusing system.
Level or secure material sheets before cutting.
Tighten machine components and check mechanical guides.
Stabilize assist gas pressure using flow regulators.

4.Abnormal Sparks During Cutting

Symptoms:

Excessive or irregular sparks appear while cutting.

Causes:

Overpowered beam: The laser burns too hot for the material.
Slow cutting speed: Too much heat builds up and vaporizes the material excessively.

Solutions:

Lower the power settings relative to the material.
Increase cutting speed to reduce thermal stress.

5.Incomplete Cuts or Penetration Failure

Symptoms:

The material remains partially joined or is not fully separated.

Causes:

Laser power too low: Insufficient energy to complete the cut.
Speed too fast: The laser passes without fully engaging the material.
Dirty optics or nozzle: Affects energy delivery.
Inaccurate focus point: Misaligned beam focus reduces penetration.
Material too reflective or dirty: Reflective metals like aluminum can scatter the beam.

Solutions:

Increase power based on thickness.
Slow the feed rate for better engagement.
Clean or replace contaminated optics.
Adjust focus settings manually or via auto-focusing.
Apply surface treatments or pre-cleaning steps for reflective materials.

6.Burn Marks or Discoloration on Edges

Symptoms:

Cut edges have brown, yellow, or black discoloration.

Causes:

Too much power or heat: Burns the surrounding area.
Oxygen-based cutting without shielding: Encourages oxidation.
Slow processing speed: Lengthens heat exposure.

Solutions:

Reduce power or use pulsed mode cutting.
Switch to nitrogen or argon shielding gas.
Increase cutting speed for cleaner edges.

7.Dross Accumulation on Underside

Symptoms:

Hardened, bead-like slag forms underneath the cut.

Causes:

Inadequate assist gas pressure: Fails to blow away molten residue.
Slow speed or low power: Causes melting without complete separation.
Incorrect nozzle gap: Alters gas delivery and beam convergence.

Solutions:

Increase assist gas pressure and flow rate.
Tune cutting speed and power to the material type.
Adjust nozzle height for optimal delivery.

8.Piercing Issues at Cut Start

Symptoms:

Laser struggles to pierce material cleanly at the start.

Causes:

Poor pierce parameters: Time or power settings are incorrect.
Beam instability: Causes initial melting without penetration.
Dirty surface or oxide layer: Reflects the laser.

Solutions:

Set a longer pierce time or use stepwise piercing.
Inspect and stabilize the beam source.
Clean the material’s surface before processing.

Summary

Laser cutting offers unmatched precision and flexibility for both small and large-scale manufacturing. However, the success of any cutting process heavily depends on fine-tuning laser settings, maintaining the equipment, and understanding material behavior. From burrs to burn marks, most issues can be resolved with the right adjustments and preventative maintenance.

Han’s Laser continues to innovate and support users globally with advanced laser cutter technology, comprehensive training, and responsive technical assistance.

Looking to improve your laser cutting performance? Contact Han’s Laser today for expert guidance and next-generation solutions tailored to your production needs.