Computer Numerical Control (CNC) machines create identical interchangeable parts. They simplify manufacturing and reduce the risk of human error producing parts.
Starting in 1949, John Parsons worked with Frank Stulen at Gordon S. Brown’s Servomechanisms Laboratory at MIT to develop a system where punch cards controlled a machining tool, called Numerical Control (NC).
This evolved into Computer Numerical Control (CNC) as computers evolved. Developing CNC was extremely expensive. CNC development ran wildly over budget, so much that Parsons lost his job. Eventually, patent royalties justified rehiring him.
Parsons originally created CNC, using IBM accounting computers, to build helicopter blades for the then new Sikorsky helicopter company.
Technologists often refer to the development of CNC as the beginning of the “second industrial revolution.”
RO: Why did it take so long between licensing the patent and the widespread use of NC?
Parsons: The slow progress of computer development was part of the problem. In addition, the people who were trying to sell the idea didn’t really know manufacturing—they were computer people. The NC concept was so strange to manufacturers and so slow to catch on, that the US Army itself finally had to build 120 NC machines and lease them to various manufacturers to begin popularizing its use.