With the advantages of flexibility and portability, handheld laser welding machines are widely used in sheet metal processing, kitchen and bathroom hardware, door and window guardrails and other fields, but in actual operation, they are easily affected by parameter setting, workpiece status, equipment maintenance and other factors, and various problems occur. The following are common problems, causes and corresponding solutions, covering three categories: welding quality, equipment operation, and safety alarms

1. Welding quality problems

This kind of problem directly affects the qualification rate of the workpiece and is the most common situation encountered in field operations.

1. Phenomenon 1: The weld is not firm and easy to crack/fall off
• Cause
• The laser power is too low, the welding speed is too fast, and the heat input is insufficient.
• The defocus deviation is too large (the focus does not fall on the welding surface of the workpiece);
• the workpiece clearance is too large, exceeding the laser cladding capacity range;
• The surface of the base metal has impurities such as oil stains, rust, and oxide layers.
• Solution
• Gradually increase the laser power or reduce the welding speed to increase the heat input;
• Adjust the distance between the gun head and the workpiece and calibrate the defocus amount (0~+2mm is recommended for conventional carbon steel welding);
• For workpieces with a gap > 0.5mm, first carry out wire filling treatment or adjust the tooling fixture to reduce the gap;
• Before welding, use a grinder and anhydrous ethanol to clean the surface impurities of the workpiece.
2. Phenomenon 2: The weld has pores and large splashes
• Cause
• insufficient purity of shielding gas (argon purity needs to be ≥ 99.99%, mixture ratio is improper);
• The protective airflow is too small and does not effectively isolate the air;
• The laser power is too high, resulting in excessive melting of the base metal;
• The tip protects the lens from contamination, and the light output is unstable.
• Solution
• Replace high-purity protective gas, preferably use pure argon gas for carbon steel welding, and argon-helium mixture for aluminum alloy welding;
• Adjust the protective airflow to 15~25L/min to ensure that the airflow covers the weld area evenly;
• appropriately reduce the power or speed up the welding speed to match the melting point of the base metal;
• After stopping, wipe the protective lenses with a dust-free cloth dipped in anhydrous ethanol, and replace them in time if the lenses are seriously scratched.
3. Phenomenon 3: The weld is blackened and severely oxidized
• Cause
• The protective gas is not turned on in time or the direction of the air flow deviates from the weld;
• There is too much dust in the welding environment, and the air is mixed into the melt pool.
• The carbon content of the base metal itself is too high or not treated with anti-rust.
• Solution
• Adjust the angle of the protective gas nozzle to ensure that the airflow is facing the melt pool, and turn on the protective gas 2~3s in advance and turn off the gas 2~3s later;
• Improve the welding environment to ventilate and remove dust to avoid dust entering the melt pool;
• For high-carbon steel workpieces, passivation treatment should be carried out in time after welding.

2. Equipment operation problems

This type of problem affects the normal start-stop and stability of the equipment, and is mostly related to maintenance, optical path, and electrical system.

1. Phenomenon 1: The handheld gun head does not emit light / the light output is unstable
• Cause
• the laser power supply is not connected or the emergency stop button is not reset;
• Loose fiber optic connectors or offset optical paths;
• Control board failure or trigger switch failure;
• Laser overheat protection triggers.
• Solution
• Check the power supply line and reset the emergency stop button to ensure that the power supply voltage is stable;
• Tighten the fiber optic connector and recalibrate the optical path (professional operation required);
• Replace the damaged trigger switch and contact the manufacturer to test the board;
• Clean the laser cooling fan and heat channel, and restart it when the temperature drops to the normal range.
2. Phenomenon 2: The handle of the gun head is severely hot
• Cause
• Continuous working time is too long, and the heat dissipation of the gun tip is poor;
• Damage to the internal optics of the gun head, resulting in heat reflection;
• Cooling system failure (water-cooled model).
• Solution
• Avoid long-term continuous welding, stop the machine for 5 minutes every 30~40 minutes of work;
• Check whether the tip lens is cracked and replace the damaged elements in time;
• The water-cooled model needs to check the cooling water flow and water temperature, clean the water tank filter, and replenish the coolant.
3. Phenomenon 3: The current/power fluctuates greatly during the welding process
• Cause
• unstable grid voltage;
• Laser driver board failure;
• The handheld gun head has poor contact with the workpiece.
• Solution
• install a voltage regulator power supply to avoid equipment and high-power electrical appliances sharing the same line;
• Contact the manufacturer to overhaul the drive board;
• Keep the tip stable during operation to avoid shaking and poor contact.

3. Safety and alarm issues

This kind of problem is related to operational safety and needs to be investigated and dealt with first.

1. Symptom 1: The device triggers an overload alarm
• Cause
• The laser power setting exceeds the rated range;
• The heat dissipation system is blocked, and the equipment temperature is too high.
• Faulty motor or drive module.
• Solution
• adjust the power to the rated range, and strictly prohibit overload operation;
• Clean the heat dissipation channel and filter, and check whether the cooling system is normal.
• After the shutdown and power outage, contact the after-sales inspection motor and drive module.
2. Symptom 2: The E-Stop button fails
• Cause
• the mechanical parts of the emergency stop switch are damaged;
• The control line is disconnected or poorly contacted.
• Solution
• Immediately stop the machine and cut off the power, and replace the damaged emergency stop switch;
• Check the emergency stop line and reconnect the loose terminal block.

4. Daily maintenance and prevention suggestions

1. Before welding every day, clean the protective lens of the gun tip and check the purity and flow rate of the protective gas;
2. Check whether the optical fiber connectors and power cords are loose every week, and clean the heat dissipation channels of the equipment;
3. calibrate the optical path and defocus amount once a month, and replace the water and filter elements of the water cooling system;
4. Avoid using the equipment for a long time in dust, humidity, and corrosive gas environments.