Robotics in spot welding

Spot welding is a type of resistance welding technique used to join thin sheets of metal together. It uses a pair of copper alloy electrodes to deliver an electric current to the metal pieces being joined. These electrodes apply pressure and conduct the electric current to the workpieces, creating a circuit. The nature of spot welding – repetitive, precise, and often high-volume – makes it an ideal application for robotics.

Welding robots usually have Five or Six-Axis arms. These arms offer the flexibility and reach needed for spot welding. This adaptability enables the robot to reach different angles and positions on the workpiece, ensuring that the electrodes are precisely positioned for each weld. 

The Multi-Axis arm contributes to the robot's versatility by allowing it to execute spot welding on complex geometries and diverse assembly lines, which is especially useful in industries such as car production.

The robots also have unique end-of-arm tooling, known as an end-effector. This end-effector contains the copper alloy electrodes required for spot welding and is capable of supplying the electric current and exerting the appropriate pressure to produce the weld nugget. The exact control of the end-effector is critical for producing uniform and high-quality welds.

Sometimes, a separate robot that has a gripping end-effector is integrated into the system to handle the workpieces. This robot is responsible for accurately positioning the pieces for welding and subsequently removing and transporting the welded assembly. Including a material handling robot like this further streamlines the workflow, reducing cycle times and enhancing overall productivity.

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Robotics in arc welding

Arc welding is a versatile and widely used welding technique that uses an electric arc to melt and fuse metals. The electric arc is formed between an electrode and the workpieces, generating intense heat that melts the metal, leading to a weld. Two prominent methods within the arc welding umbrella are Tungsten Inert Gas (TIG) Welding and Metal Inert Gas (MIG) Welding.

For TIG welding, the robot is equipped with an end-effector that holds the non-consumable tungsten electrode and controls its movement along the weld path. But for MIG welding, the robot’s end-effector incorporates a wire feed mechanism that continuously feeds the consumable wire electrode into the arc, maintaining a steady rate aligned with the welding speed.

In arc welding, the robotic welder is often equipped with a database containing presets for different material types and welding conditions. This database guides the initial setup for the shielding gas mix. Sensors monitor the quality of the weld in real-time, providing feedback to the control system. Based on sensory feedback, the robotic system can make instantaneous adjustments to the shielding gas composition to maintain weld quality.

Programmable Logic Controllers (PLCs) are the brains of the operation, allowing the robotic system to adjust the gas mix according to the welding specifications for different materials. By controlling the valves and flow meters connected to different gas cylinders, the PLC can vary the ratios of argon and carbon dioxide in the mix.

A robotic MIG welder needs a direct and uninterrupted connection to an electrode wire source. This ensures a consistent and continuous supply of the consumable electrode, which is important for maintaining the arc and forming the weld.  Since TIG welding uses a non-consumable tungsten electrode, the robots need to be equipped with features or auxiliary systems for electrode maintenance to ensure optimal performance. 

The benefits of automated welding with robots

Automated welding with robots offers huge benefits for your welding operations. Robotic welders can handle the most complex jobs with speed and precision. Once programmed, they churn out perfect welds every time. They reduce waste, improve quality control, and take the risk out of the job for your human welders.

Steadiness and precision

During spot welding, robots can ensure the exact positioning and alignment of the copper alloy electrodes on the workpieces, critical for the quality and strength of the weld. They also apply consistent pressure through the electrodes, essential for creating uniform weld nuggets and reducing defects.

They also maintain a steady hand and consistent arc length, essential for TIG welding, which requires finesse and stability. This steadiness results in uniform welds and reduces the likelihood of defects. It also helps in delivering consistent welds in large-scale MIG manufacturing.

The high precision of robotic arms allows for exact electrode positioning and movement, especially crucial for TIG welding on thin or delicate materials. This precision also ensures accurate electrode positioning and trajectory, essential for the quality and integrity of MIG welds. This helps to save money on wastage and increase efficiency while producing a higher quality product in a more reliable fashion.

Cost and time savings

Robotic welding reduces wasted time, wasted materials, and rework, significantly cutting costs. Robots operate 24/7 with minimal downtime, maximizing productivity. They also reduce expenses related to employee healthcare, safety equipment, and training.

Robotic welding systems have a high upfront cost. However, the long-term savings in time, materials, and labor provide an excellent return on your investment. Many businesses find their robotic welding systems pay for themselves within 1 to 2 years.

Enhanced productivity and safety

Robots are capable of operating without fatigue for longer hours, significantly increasing the throughput of welding tasks and optimizing productivity. Deploying robots for welding tasks reduces human exposure to hazards such as fumes, sparks, and UV radiation, promoting a safer working environment for your staff.

They can maintain an optimal welding speed, adjusting in real time to the material characteristics and weld requirements, which is particularly beneficial for the detailed TIG process. They can also operate continuously without fatigue, significantly increasing the throughput of TIG welding tasks, especially in large-scale production.

Quality monitoring and control

Advanced robotic systems equipped with sensors and cameras can monitor the weld pool and arc in real-time, making instant adjustments to maintain weld quality. The robots can also record welding parameters and outcomes, facilitating quality control and enabling continuous improvement in the welding process.

They can also monitor the welding parameters and the formation of the weld nugget in real-time, enabling instant adjustments and quality assurance. The systems log data related to each weld, facilitating quality control and continuous process improvement

Labor optimization 

With a notable shortage of skilled welders, utilizing robots for welding allows the available human workforce to focus on more intricate, specialized welding tasks.

By automating routine and repetitive welding tasks, like rudimentary spot welds, skilled welders can be allocated to more complex, high-value tasks that require craftsmanship and expertise.

While robots handle routine welding, the existing workforce can be trained and upskilled to manage, program, and maintain robotic systems, thereby enhancing their skill sets.

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Conclusion

Embracing robotic welding is a strategic move in addressing the current welder shortage and preparing for the future of the industry. Robots not only alleviate labor issues but also bring consistency, efficiency, and safety to the welding process, allowing skilled welders to concentrate on refining their craft.

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Next steps

If you are ready to automate your welding processes, you don’t have to worry about importing and installing a robot by yourself. RO1 by Standard Bots is built and assembled in the United States. 

The RO1 stands out in multiple ways:

• It can operate at least three times longer than a human in a hot, smoky, welding environment and can safely handle heavy end-effectors for different types of welding.
• It comes equipped with a vision system capable of spotting weld defects and other deformities
• It comes standard with M8 4 and 8-pin connectors, ensuring compatibility with major welding tool suppliers like Miller and Panasonic.

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Speak to our solutions team today to get personalized information for your welding needs.