Computer Numerical Control (CNC) machining was invented more than 50 years ago. This new machining technology has improved precision capabilities and created countless products of different shapes and sizes. Across all sectors – from defense to automotive to aerospace to medical – this technology is now part of the global industrial DNA.
The History of CNC machining
The massive industrial production of the United States during the Second World War (planes and other vehicles for the army) continued after the end of its construction with the expansion of infrastructure and transport. It was, therefore, necessary to find a solution to respond effectively to the growing demand for new industrial products.
John T. Parsons, who worked in the production of helicopter rotor blades, was the first to champion CNC machining. The interpolation curves used for the rotor blades could be applied to the machining using specific calculation methods.
Based on the innovations of John T. Parsons, the MIT lab then developed a machine capable of using computer methods to manufacture precision parts. Thus, they could use Cartesian coordinates – numerical control – to direct the machine and its moving parts to manufacture parts with great precision. This automation grew in sophistication throughout the twentieth century and continues to grow today.
CNC Machining vs. Traditional Machining
In traditional machining or bar turning, a skilled operator operates a machine to remove and form metal by manually controlling it using thumbwheels and dials. The specifications provided by a plan carry out this operation.
CNC machining performs the same functions as traditional machining – turning, drilling, milling, reaming, grinding, and other metal forming and metal removal functions – but this technique uses computer numerical control rather than manual control. A program is coded beforehand by an operator or a CAM (Computer Aided Manufacturing) tool. This program is then loaded onto the machine, and the operator is responsible for adjusting the latter to meet the dimensions and tolerances of the part perfectly. After this adjustment phase, CNC machining allows continuous precision from the first cut to the 500th.
This machining is much more precise and has largely supplanted traditional machining in manufacturing and industrial production. It uses mathematical coordinates and computing power to achieve the same goal with the utmost precision. Specifically, the CNC uses Cartesian coordinates.
CNC Machining Process
CNC machining uses subtractive processes, which means the raw material is machined to its final shape by material removal. Holes are drilled, reamed, and metal is shaped with varying diameters and shapes.
CNC machining differs from additive manufacturing, like 3D printing, where materials are added, layered, and deformed to achieve a specific shape. There is also injection molding, where the material is injected into a mold to obtain the expected shape.
On the other hand, CNC machining makes it possible to work with various materials such as stainless steel, titanium, aluminum, steel, Inconel, pure iron, plastics, or copper alloys. This versatility has contributed to the development of CNC machining in all industries.