How to Replace the Focusing Lens Assembly When Using the Cleaning Function on a Laser Welding Machine
Replacing the focusing lens assembly in a laser welding machine (especially after using the cleaning function, which may contaminate or damage the lens) requires careful handling to ensure safety and precision. Follow these steps:
Pre-Replacement Preparations
1. Safety Measures
Turn off the laser power and unplug the machine to ensure complete electrical isolation.
Wear anti-static gloves and safety goggles to avoid contamination or electrostatic damage.
Allow the machine to cool down if it was recently in use to prevent burns.
2. Tools & Materials
Lint-free wipes, anhydrous ethanol or isopropyl alcohol (purity ≥ 99.7%).
Lens tweezers or suction pen (avoid touching the coated surface with fingers).
New focusing lens assembly (ensure correct model, focal length, diameter, and coating type).
Replacement Steps
1. Removing the Old Lens Assembly
Open the laser welding machine's housing and locate the focusing lens module (usually at the bottom of the laser head).
Loosen the lens retaining ring or clamp using a screwdriver (note the disassembly order for reassembly).
Gently remove the old lens using a suction pen or tweezers to avoid scratching the lens or housing.
2. Cleaning the Lens Holder
Use compressed air to remove dust or metal debris from the lens holder.
Wipe the inner surface with a lint-free cloth lightly dampened with ethanol (wipe in one direction to avoid fiber residue).
3. Installing the New Lens Assembly
Place the new lens into the holder using tweezers (the coated side usually faces the laser beam-refer to the manual).
Tighten the retaining ring evenly to ensure the lens is level (over-tightening may deform the lens).
Check the sealing (if applicable) to ensure no gaps.
4. Calibration & Testing
Reconnect the power and perform a low-power beam alignment (e.g., use a red dot laser to check centering).
Test focus quality using a white paper or energy meter, adjusting the focal length for optimal welding/cleaning performance.
Run the cleaning function to verify stable laser output.
Key Precautions
Avoid Contamination: Work in a dust-free environment to prevent oil or fingerprints on the lens.
Correct Lens Orientation: The focusing lens is typically convex-ensure proper alignment (wrong installation causes beam distortion).
Torque Control: Tighten screws diagonally in stages to ensure even pressure.
Regular Inspection: The cleaning function generates spatter, so inspect the lens frequently (e.g., weekly).
Troubleshooting Common Issues
Uneven Beam Spot: Recheck lens alignment or contamination.
Error Alarms: Verify lens compatibility or check optical sensors.
Reduced Cleaning Efficiency: Lens may be dirty or damaged-clean or replace again.
--------Victor Feng
Rayther Laser