From Assembly Line to Automation: The Role of Robotics in Machining and Fabrication

April 28, 2023
Arrow - From Assembly Line to Automation - The Role of Robotics in Machining and Fabrication

As robotics becomes more prevalent in metal machining and fabrication, we are seeing a massive shift in how we do business.  

Today, industrial robots perform complex processes in a diverse range of industries. These tasks include everything from cutting and welding to machine tending and finishing.  

However, we still have a long way to go before robotics supersedes manual machining and fabricating processes. Industrial robots remain limited in precision, speed, rigidity, and flexibility for various reasons. This limits their potential applications in creating machined castings, fabrications, and assemblies.

Despite these limitations, robotics has become indispensable in various heavy manufacturing sectors.

Sure, robots haven’t quite matched the accuracy and speed of CNC machines yet. But their versatility, expansive workspace, and multitasking abilities give them a unique edge. As these technologies continue to evolve, the barriers to entry will decrease.

It’s only a matter of time before robotics becomes an integral part of every manufacturer’s toolkit. 

As a manufacturer, by taking a good hard look at your production needs, you can harness the full potential of this evolving technology. And trust me—the rewards are well worth it.

The Robotics Revolution in Metal Machining and Fabrication

The evolution of industrial robotics over the last 20 years alone has been nothing short of astounding. But the story of the robotics revolution can be traced much further back than that, in the early days of assembly line production. 

Robotic Roots in the Automotive Industry

The automotive industry has always been at the forefront of technologies to boost efficiency and productivity, and industrial robotics are no exception. General Motors (GM) introduced the world’s first industrial robot at the Ternstedt plant in Trenton, NJ, in 1961.

Despite their limitations, these first-generation robots caught on. They were more flexible than hard-tooled transfer lines and cam-based assembly automation. Consequently, they were often deployed to automate tasks utilizing their programmable, multi-position flexibility. 

Today, the automotive industry remains a leader in robotics adoption. Auto manufacturing boasts the largest number of robots working in factories worldwide. Moreover, the operational stock of robots in the automotive sector has reached a new record of approximately one million units, accounting for an impressive one-third of the total number installed across all industries. 

Improvements to Safety and Sophistication

Modern robots display a level of sophistication that would have been unimaginable even just five years ago. The integration of built-in vision and force sensors has vastly expanded the range of tasks they can perform safely and reliably—including tasks once reserved exclusively for human workers. Some advanced robots can even monitor their performance, recommend spare parts when needed, and send text messages for preventative maintenance alerts

Manufacturers have also improved robot safety. Today, we have redundant safety controls, powerful software, and real-time workspace scanning sensors. With proper safety risk assessments in place, large and powerful robots can now work alongside human operators (these co-working robots are known as cobots.) This marks a new era of collaboration and efficiency.  

A prime example of a company with seamlessly integrated robotic welding capabilities is CGL Manufacturing, an Arrow company. CGL serves Original Equipment Manufacturers (OEM) in the automotive sector. Fully integrated robotic welding refers to a system where the robot is part of a more extensive welding process. The robot controls every aspect of the process, from positioning the parts to be welded to selecting the right welding parameters.

Robots have become integral to the manufacturing process. As technology progresses, we can expect even more innovation.

Challenges and Opportunities

Robotics has made significant strides in the world of metal machining and fabrication. With that said, it’s essential to acknowledge that robots are not yet ready to replace CNC machines and their operators.

Where Robotics Fall Short of Human CNC Operators

Limitations in accuracy, speed, rigidity, and programming language standardization have impeded the development of robotic machining and fabrication. This is especially true areas where precision is non-negotiable.

For example, high-end CNC machines can achieve a precision of 0.02 mm to 0.05 mm. Recent advances in robotics have only just enabled robots to reach accuracies between 0.1 and 0.2 mm. While comparable or superior to rapid prototyping machines like STL or SLS, this puts robots far below what we can achieve manually.

One of the most significant limitations of robots is their lack of stiffness or rigidity. This affects their accuracy with hard materials.

Industrial robots typically have a stiffness of less than 1 N/µm. Conventional CNC machine tool centres often exceed 50 N/µm. The natural frequencies of robots are also much lower than those of traditional CNC machines which can reach several hundred or even a thousand Hz.

Opportunities for Efficiencies

However, the low stiffness of robots does not pose a significant technical challenge in all applications. Robots are viable in handling, welding, assembling, or other operations where external forces mainly result from the robot’s acceleration and gravitational effects.

Robots have not yet advanced to the point where they can replace machine tools in tasks requiring high precision and stiffness. But they offer immense potential in other tasks related to machining and fabrication , including:

  • Pre-Production Processes, such as removing rust from large metal sheets before cutting. Robots can often perform these manual applications at around half the cost of a machine tool. They provide a more cost-effective solution without compromising quality or precision.
  • Finishing Applications, such as deburring, polishing, and surface finishing. These tasks often need consistent force and precision which is challenging for human operators. Robots can perform these tasks more consistently, delivering a higher quality finished product. Robots can also be equipped with various end-effectors and tooling options to adapt to different tasks quickly.
  • Materials handling is another application for robotics in machining and fabrication firms. Automated guided vehicles (AGVs) and autonomous mobile robots (AMRs) can perform tasks like stacking, lifting, and transporting. This allows manufacturers to focus on more valuable tasks.

Given these factors, many companies have opted for a complementary approach. Manufacturers can capitalize on both technologies’ strengths for optimal efficiency and output.

We can expect further use of robotics in machining and fabrication shops as technology evolves.

How the Landscape of Industrial Robotics is Evolving

Machining functions such as cutting and welding accounted for only 25% of total industrial robot applications in 2018. However, as robotics evolve, more and more processes across various industries will likely be automated.

One key driver behind this growth is the simplification of robot programming. Modern, user-friendly interfaces and technologies that enable robots to self-program through operator hand guidance have made programming more accessible to non-experts. This innovation reduces reliance on specialist programmers, allowing companies to adapt and scale their production processes more efficiently.

What’s more, the costs of adopting industrial robotics are declining as the return on investment is increasing. Installation and integration costs account for up to two-thirds of the overall cost of an industrial robot. The speed and efficiency offered by robotics help to lower costs, improve productivity, and ensure worker safety. For example, welding robots can achieve arc-on times of 80% or even 95% for larger parts with long seams. Human operators have on-arc times of less than 50%, which decreases further with fatigue.

As these technologies continue to evolve, the barriers to entry will decrease. More manufacturers will recognize the vast advantages robotics offers in their production processes.

It’s an exciting time to be in this industry, and you won’t want to miss where it goes next.

For more information


Mike Ritchie

President and CEO

Arrow Machine and Fabrication Group

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