The History of CNC Machinery
A modern mainstay of manufacturing and production, computer numerical control, or CNC, goes back to the 1940s when the first Numerical Control, or NC, machines emerged. However, turning machines appeared before then. In fact, a machine used to replace handcrafted techniques and increase precision was invented in 1751. It would be a while until the concept would take on the capabilities of a modern CNC production company.
The machining techniques that led to CNC manufacturing marked the start of industrialization. Today’s definition of CNC machining is more specific. It involves entering 3D files into a computer, which runs a program that controls the motion of tools within a machining center. The process is fully automated, from the axis and speed of rotation of cutting tools to achieving the desired dimensions of the part.
What Is a CNC Machine?
A CNC machine is a system combining multiple tools (including drills, lathes, and milling tools), which are built into cells from which the machine can select and use them. It is designed to manufacture three-dimensional parts. The simplest machines move in one or two axes. On the other hand, more advanced systems feature X- and Y-axis motion and can move longitudinally in the Z-axis. Many are capable of rotational motion and even flipping parts automatically so material can be cut on all sides with no manual intervention.
The Early Days of CNC Work
Although the idea had been around for some time, the first Numerical Control concept wasn’t developed until 1949. John T. Parsons, an early computing pioneer, developed it as part of an Air Force research project carried out at the Massachusetts Institute of Technology (MIT). An experimental milling machine was built at the institute’s Servomechanisms Laboratory, with the goal of using motorized axes to produce helicopter blades and stiffer skins for aircraft.
Parsons Corporation in Traverse City, Michigan, got to work on the first system even before the MIT collaboration. Parsons was able to use an IBM 602A multiplier to calculate airfoil coordinates. The data points were fed into a swiss jig borer by feeding punched cards into the system. Preprogrammed information could be used to produce parts for helicopters; this was the precursor to CNC machine programming.
The idea was further developed and, in 1952, Richard Kegg (in collaboration with MIT) introduced the Cincinnati Hydro-Tel, a 28-inch vertical-spindle contour milling machine. Its commercial introduction came with a patent for a “Motor Controlled Apparatus with Positioning Machine Tool.” The initial prototype, although it was operated using eight-column paper tape, a tape reader, and a vacuum-tube electronic control system, became a focus for future developments.
Early CNC machines in the 1940s and 1950s used punched tape, which was then commonly used in telecommunications and data storage. This technology was replaced by analog computing technologies. From the 1960s into the 1970s, digital technologies emerged, making the production process automated and more efficient.
Parsons was awarded for his early work. In 1968, he received the first Joseph Marie Jacquard Memorial Award from the Numerical Control Society. The Society of Manufacturing Engineers awarded him an honorary plaque in 1975, which named Parsons “The Father of the Second Industrial Revolution.”
Evolution of Today’s CNC Factory
The highly automated motion control systems manufacturers now used are still based on the three primary components of their predecessors. They require a command function (whether a digital or analog system, a cam follower, or a flap handle to activate it); a drive/motion system such as a motor, cylinder, valve, or clutch; and a system that provides feedback, such as an encoder. In early NC machines, a control level would ride on a cam. In turn, the motor would rotate to operate the machine, but, if the feedback cable broke, the fluid flow couldn’t be stopped.
Modern CNC machines are electronically controlled so this scenario is highly unlikely. The end results are now more predictable. Also, they can use just about any kind of material, including metal, wood, plastic, fiberglass, or foam.
In addition, novel forms of machining have been developed. Using the same concept as CNC machining, they include Electron Beam Machining, Electrical Discharge Machining, and Photochemical machining. These and others are often selected depending on the material used in the mass-production process. Also common are laser, oxy-fuel, water-jet, and plasma cutting machines.
Building on Rapid Prototyping
The perspective of rapid prototyping has changed over the years, but the concept was applied from the very first punched tape, numerical control systems. Before then, all parts were machined by hand; even punched tape systems revolutionized the process. Nowadays, there are many prototyping options to choose from depending on the material used, economics, and the complexity of CNC parts.
The available tools and axes of rotation still make CNC machines appealing and extremely useful. With the advent of 3D printing, these advantages have begun to show their limitations. A 3D printer can produce complex parts, including their internal components. Depending on the application, material choices may be limited, so CNC systems remain the preferred choice, especially for prototype development.
Significance of CNC Manufacturing Today
The role of traditional machinists is quickly fading. In the 21st century, the demand for CNC specialists has been growing. Organizations such as the Institute for Technical Trades offer training to equip machinists with the skills needed to work for employers in this field. In many industries, the job outlook is robust; some predict technology jobs such as operating CNC equipment will account for 40% of future open job positions.1
CNC Production Machining with Laszeray Technology LLC
We are a full-service CNC production company specializing in CNC machining and rapid prototyping for the aerospace, oil and gas, medical device, transportation, electronics, and other i
ndustries. Our machining operations include four- and five-axis capabilities. We can apply lathes, mills, grinders, routers, and crane lifts to production runs.
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