Your Guide to Robotic Spot Welding





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Robotic spot welding is a critical technique in metal fabrication, especially in the production of automobiles, appliances, and other metal products. It involves using robotic systems to apply pressure and pass an electric current through overlapping metal parts to create a strong and permanent bond.

As with any welding process, proper preparation, equipment, and technique are crucial for successful robotic spot welding. One of the benefits of using robotic systems is their ability to maintain consistent quality and precision, even with complex shapes and large production volumes. This helps ensure the longevity and reliability of the final product, as well as improve overall production efficiency.

To achieve optimal results with robotic spot welding, it is essential to properly program the robots, select appropriate welding parameters, and ensure proper alignment of the workpieces. Additionally, regular maintenance and calibration of the equipment are critical to ensure consistent performance and prevent downtime.

Robotic spot welding is a powerful tool for metal fabrication and offers significant advantages over manual spot welding. You can achieve efficient, high-quality results by understanding the process and following best practices.


What is Robotic Spot Welding

Robotic Resistance Spot Welding (RSW) is an advanced welding process that employs robots to weld two metal forms together by applying pressure and electric current to their overlapping parts. The process is sometimes referred to as spot welding and is characterized by welding a small area, or “spot,” at a time rather than welding an entire seam or joint.

Robotic spot welding involves using a welding machine and robots to generate and control the electric current that flows between two electrodes placed on either side of the metal component. The robots ensure precision in the welding process, producing a series of small, tightly controlled welds that create a strong and consistent bond between the metal pieces.

Robotic RSW is widely used in manufacturing automobiles, appliances, and various metal products, where high-quality, cost-effective, durable, and reliable products are required. One of the main advantages of using robots in spot welding is their ability to work with complex shapes and large production volumes while maintaining consistent quality and precision.

Advantages of Spot Welding:

  • Speed: Robotic spot welding is fast and efficient, ideal for high-volume production.
  • Strength: Robotic spot welding produces a strong, permanent bond between metal sheets, making it optimal for high-strength applications.
  • Cost-effectiveness: Robotic spot welding is cost-effective, requiring less material and labor than other welding methods.
  • Versatility: Spot welding can be used on various metal forms, including metal sheets, tubes, and other shapes. However, the specific types of metal forms that can be welded depend on the capabilities of the robotic spot welding system and the welding process parameters.
  • Precision and Consistency: Robotic spot welding machines are equipped with controls that allow for precise adjustments to the welding parameters, ensuring consistent quality and reducing the risk of defects. Robots also ensure that the welding process is accurate and consistent, even with complex shapes and large production volumes.
  • Improved Safety: Robotic spot welding eliminates the need for manual welding, which can be hazardous for workers. By using robots, manufacturers can improve safety in the workplace while maintaining high productivity levels.

Disadvantages of Spot Welding:

  • Limited joint access: Robotic spot welding requires access to both sides of the metal pieces being welded, which can be challenging in some applications, limiting the ability to weld complex shapes or parts.
  • Size limitations: Size limitations: Robotic spot welding is generally suitable for welding metal sheets up to 5mm thick. For thicker metal sheets, a different welding process may be more appropriate.
  • Equipment: Robotic spot welding requires specialized equipment, which can be expensive and complex to maintain. However, those costs can be offset by the speed and efficiency of the process.
  • Weld strength: The strength of a spot weld is limited by the size of the weld, making it essential to consider the design of the metal sheets being welded carefully.


How Does Spot Welding Work

How Does Robotic Spot Welding Work

To prepare for robotic spot welding, it is important to have all necessary equipment, including spot welders, electrode caps, weld tips, and protective gear. The metal components to be welded should be thoroughly cleaned to remove any dirt, oil, or other contaminants that could interfere with the welding process. This can be accomplished using a degreaser, wire brush, or sandpaper.

Before welding, it is crucial to inspect the metal to ensure it is free of cracks, dents, or other defects that could affect the quality of the weld. If any defects are present, they should be repaired or removed before welding. Proper electrode selection is also important, as electrodes must be the correct size and material for a successful weld.

1. Setting the Machine 

First, select the appropriate current, time, and pressure settings for the metal pieces being welded to set up the spot welding robot. Determine the component’s thickness and material type and consult the manufacturer’s specifications for the recommended settings. Adjust the welding program controls to match those specifications.

The current setting determines the amount of electrical energy used for the welding process, while the time setting determines the duration of the weld. The pressure setting determines the force applied to the metal during welding. Correct settings are crucial to achieving consistent and high-quality welds.

Programming the robotic system to apply the correct settings is critical to ensure that the welding process produces consistent and high-quality results. Following these steps, the robotic spot welding machine can be set up for optimal performance, achieving efficient and effective spot welds.

2. Clamping 

Proper clamping is crucial for a successful robotic spot welding process. It ensures that the components are aligned and overlapping correctly, which is necessary for a strong and reliable weld. In robotic spot welding, the pieces are usually clamped between the electrodes of the welding machine.

The clamping pressure is adjustable and should be set according to the thickness and type of material being welded. Too much pressure can cause deformations or damage the piece, while too little pressure can result in a weak or failed weld. Therefore, the proper clamping pressure is essential to achieve consistent and high-quality results in robotic spot welding processes.

3. Inspection 

Inspect the weld to ensure it is solid and free of defects. It’s important to regularly inspect the spot welds to ensure they are strong and reliable and to identify and address any issues as soon as they arise.

The type and frequency of inspection will depend on the application and the specifications for the welded parts. Here are the steps for inspecting a spot weld:

  • Visual inspection
  • Tensile test
  • X-ray inspection
  • Ultrasonic inspection
  • Microscopic inspection

4. Welding 

To begin the welding process, the robotic system is programmed to position the pieces accurately, and the welding machine is turned on. The operator then adjusts the current, time, and pressure settings according to the specifications of the material being welded. 

Once the settings are adjusted, the robotic system applies pressure to the components, and the welding machine passes an electric current through the overlapping parts. This causes the metal to fuse, creating a strong and permanent bond.

5. Cooling 

After the welding process is complete, the components are allowed to cool and solidify. Proper cooling is important because it helps control the solidification rate and minimize any distortions in the final piece.

If the metal cools too quickly, it may become brittle and susceptible to cracking, while if it cools too slowly, it may deform. Several factors influence the cooling process, such as the size of the weld, the type of metal being welded, and the cooling rate.

Some welding machines in robotic spot welding are equipped with cooling fans or water-cooling systems to help control the cooling rate. These cooling systems help ensure the material is cooled correctly, minimizing distortions and ensuring the final product meets the required specifications.


Call Us For Welding Services

Robotic spot welding is a fast, efficient, and reliable process for welding metal components together. Whether you’re welding small parts or large assemblies, it’s important to have a solid understanding of the process and follow proper safety procedures to ensure your welds are strong and defects-free.

At Glenn Metalcraft, we have four robotic welding cells:

  • (2) FANUC ArcMate 120ib,
  • FANUC ArcMate 100ic,
  • FANUC ArcMate 50ic,

and extensive experience providing top-quality welding services. We’re dedicated to helping our customers achieve the best results possible. Whether you need a single weld or a large production run, we have the expertise and equipment to do the job correctly.

Contact Glenn Metalcraft for more information.

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