CNC literally means computer numerical control. In a broad sense, any computer numerically controlled machine can be called a CNC machine. Such as CNC punching machines, CNC laser cutting machines,s and so on. This article is about the history of CNC milling machines, or machining centers. In the processing industry, there is no specific type of machine tool. When only CNC is mentioned, it refers to CNC milling machines (machining centers).
The First CNC Machine
The origin of the matter is how to machine the airfoil curve. Different airfoil curves will exhibit different lift, drag, stall angles, etc. at various airspeeds. Machining blades or airplane wings with specific airfoil curves and shapes was a big challenge. Making such complicated parts with a manual milling machine is laborious and imprecise.
The story begins with John T. Parsons, an engineer and inventor, who is credited with pioneering the concept of numerical control. In 1949, Parsons, along with his employee Frank Stulen, developed a system that utilized punched cards to control the movements of machine tools. This system laid the foundation for what would later become known as computer numerical control (CNC).
MIT, the Massachusetts Institute of Technology, played a significant role in the story. Parsons, who was an alumnus of MIT, collaborated with the university’s Servomechanisms Laboratory to further develop and refine his numerical control system. Together, they conducted research and experiments to improve the capabilities and functionality of NC machines.
With the support and expertise from MIT, Parsons continued to refine his numerical control system, making significant advancements in the field. The partnership between Parsons and MIT led to the establishment of the first commercial NC machine tool company, the Parsons Corporation.
The NC (numerical control) machine at that time is not a CNC (computer numerical control) machine yet. The computing systems in the 1940s and 1950s used punched cards as a primary input method. Operators would create programs and data on punched cards, which were then fed into the computer for processing. That is why the “auto” machine at that time is called “NC” not “CNC”. In the late 1950s and early 1960s, keyboards and screens, also known as consoles or terminals, began to replace punched cards for certain tasks.
The term “CNC” itself became more commonly used in the 1970s when computer technology and miniaturization advanced to a level that allowed for the integration of computers directly into machine tools. This integration marked a significant milestone in the history of CNC machines, leading to their widespread adoption and revolutionizing the manufacturing industry.
The Developing History of CNC Machines
Early Developments (1940s-1950s):
The concept of Numerical Control (NC) took shape in 1949 when John T. Parsons, an early computing pioneer, developed it during an Air Force research project at MIT. The project aimed to create motorized axes for manufacturing helicopter blades and aircraft skins.
Parsons Corporation in Traverse City, Michigan, preceded the MIT collaboration by using an IBM 602A multiplier to calculate airfoil coordinates. The data was then fed into a Swiss jig borer using punched cards. This marked the early stages of CNC machine programming.
In 1952, Richard Kegg, in collaboration with MIT, introduced the Cincinnati Hydro-Tel, a vertical-spindle contour milling machine. It was commercially launched with a patent for a “Motor Controlled Apparatus with Positioning Machine Tool.” The initial prototype used eight-column paper tape, a tape reader, and a vacuum-tube electronic control system, setting the stage for future advancements.
During the 1940s and 1950s, early CNC machines utilized punched tape, a technology commonly used in telecommunications and data storage. This was later replaced by analog computing technologies. In the 1960s and 1970s, digital technologies emerged, leading to automated and more efficient production processes.
Parsons received recognition for his early contributions. In 1968, he was honored with the first Joseph Marie Jacquard Memorial Award from the Numerical Control Society. The Society of Manufacturing Engineers also presented him with an honorary plaque in 1975, naming him “The Father of the Second Industrial Revolution.”
Pioneering CNC Technology (1950s-1960s):
In the 1950s, the Massachusetts Institute of Technology (MIT) pioneered further advancements in numerical control technology. John T. Parsons, together with MIT engineer Frank L. Stulen, developed the concept of “numerically controlled milling” and built the first milling machine controlled by data stored on a punched card.
CNC Emerges (1960s-1970s):
Today, thanks to electronic control, such scenarios are highly improbable, and the outcomes of CNC machining are more predictable. CNC machines have the versatility to work with various materials, including metals, wood, plastics, fiberglass, and foam.
Furthermore, innovative machining techniques have been developed based on the principles of CNC machining. These methods include Electron Beam Machining, Electrical Discharge Machining, and Photochemical Machining. The choice of technique often depends on the material used in the mass-production process. Additionally, laser, oxy-fuel, water-jet, and plasma-cutting machines have become common in the industry.
Industry Adoption (1980s-1990s):
In the 1980s and 1990s, CNC technology gained widespread acceptance in the manufacturing industry. The development of microprocessors, improved software, and increased affordability of computers made CNC machines more accessible to smaller businesses. CNC machines began replacing traditional manual and mechanically automated machines, offering enhanced accuracy, repeatability, and flexibility.
Advancements in Automation (2000s-2010s):
The 21st century brought further advancements in CNC technology. Machining centers, lathes, and other CNC machines became increasingly integrated with robotic systems for enhanced automation. This integration allowed for lights-out manufacturing, where machines could run unattended for extended periods, increasing productivity and reducing labor costs.
Current Trends and Future Outlook:
Modern CNC machines continue to evolve with advancements such as faster processing speeds, improved precision, better connectivity, and advanced control systems. The integration of artificial intelligence (AI) and machine learning (ML) algorithms into CNC systems is a growing trend, enabling predictive maintenance, optimization of cutting parameters, and adaptive control.
Building on Rapid Prototyping
Over the years, the perspective on rapid prototyping has undergone changes, but its roots can be traced back to the earliest punched tape numerical control systems. Prior to this innovation, all parts had to be manually machined, making the introduction of punched tape systems a revolutionary development. In today’s world, there are numerous prototyping options available, each dependent on factors such as material selection, cost-effectiveness, and the complexity of CNC parts.
Despite the proliferation of alternative methods, CNC machines with their array of tools and rotational axes continue to possess significant appeal and utility. However, the emergence of 3D printing has revealed certain limitations in these traditional systems. 3D printers have the capability to manufacture intricate parts, including their internal components. While material options may be restricted depending on the specific application, CNC systems remain the preferred choice, particularly for the development of prototypes.
Advantages of CNC Machines
Advanced CNC machining provides numerous advantages for modern businesses. Let’s explore the various ways in which advanced CNC machines benefit industries today:
The availability of CAD programs empowers individuals to create prototypes regardless of their expertise in manufacturing. Rather than requiring extensive knowledge in the field, engineers simply need to replicate their design idea in the computer to have the CNC machine bring it to life. By keeping the design in digital format, any modifications to the part’s shape can be swiftly implemented by repeating the computer processing for a new model.
Small and Large-Scale Production Capabilities
CNC machines enable businesses to handle orders ranging from a single piece for testing purposes to massive high-volume projects. This versatility allows a business to initially create a single prototype using CNC machining. Once the model has undergone physical testing and any necessary final design adjustments have been made, the finalized version can swiftly transition into high-volume production.
The availability of a wide range of materials for CNC machining provides another significant advantage to this process. At American Micro Industries, we utilize various materials such as phenolics, rigid foam, plastics, and carving foam. Within each material category, there are specific types available, allowing you to select the one that best suits the desired properties for your project. Machined parts made from these materials often include electronic device cases, insulation, and prototypes. The diverse selection of material options expands the range of parts that can be created through CNC machining.
Embrace Today’s CNC Technology
Over the decades, CNC machinery technology has undergone a remarkable evolution, transitioning from punch-driven devices to computer-controlled machines. Despite these advancements, the core advantages have remained consistent: companies benefit from automated precision with significantly lower margins of error compared to what human metalworkers could achieve, all while achieving higher throughput. Moreover, the history of CNC technology is far from reaching its endpoint, as further advancements are on the horizon.
In the present day, CNC machines offer greater predictability than their predecessors. Earlier models relied on rotating motors and cam-operated control levels, which posed the risk of errors and yielded unpredictable outcomes if the feedback cable broke. With the current electronically controlled machines, such uncontrollable situations are highly unlikely. As a result, businesses can rely on CNC machines to consistently deliver the expected results.
Advanced software tools now enable businesses to create 3D models and generate precise drawings for each project. CNC machines utilize these digital designs to carve out prototypes using the highest-quality materials, bringing them to life with exceptional precision.
Throughout the changes in NC and CNC technology, the accuracy, precision, and speed of CNC machinery have significantly improved. However, there is still room for further enhancements. As engineers continue to refine CNC machinery, more companies are likely to recognize and embrace the advantages of CNC machining for their projects.