Description

Silver-grey metal ashtray with cork bottom. Triangular with rounded corners, parabolic cutout with "ears" at wide end. Raised letters: "APT 11 // AIA MIT AMC// FEB. '59"

This simple aluminum ashtray represents a revolution in the machine tool industry. It was produced in 1959 as part of a demonstration of a milling machine controlled by a computer punch tape instead of a human operator. The development of this machine was more than a decade in the making and the result of a complex story about competing visions for this technology. After World War II, the U.S. Air Force gave several contracts to the Parsons Corporation to develop further the numerically control machining innovations made by its founder John Parsons. Interested in experiments being conducted at the MIT Servomechanisms Laboratory, Parsons proposed in 1949 that MIT become a project subcontractor to provide expertise on automatic control. Over the next 10 years, MIT gained control over the entire project as the Servomechanisms Laboratory vision of "three-axis continuous path control" supplanted the original Parsons conception of "plunge-cutting positioning." Conflict always shapes technology but this particular story, chronicled by historian David Noble, has become a significant object lesson in the history of technology.

Additional Information

Numerical control technology that revolutionized the machine tool industry was a major project of the MIT Servomechanisms Laboratory in the 1950s. Computer-controlled 3-D printers are everywhere today, from the highest-tech industrial manufacturing to the back sheds of hobbyist makers. But in the 1950s, machine tooling was still done mostly by hand, relying on the guidance of a human machinist to set the initial pattern recorded in a template. This method was fine for relatively simple repeatable patterns -- a million fenders for the current model year -- but was not an efficient way to do experimental complex one-time or short-run parts -- half a dozen fender variations to test for next year. Industry leaders and scientists could see how useful it would be to go directly from a computer design to a finished milled product and approached MIT to find a solution. The MIT Servomechanisms Laboratory and consultants from the Whirlwind project worked together to create numerically-controlled milling machines that would take direct input from punched tape. The ashtray shown here was a demonstration of the complex shapes that could easily be milled by computer command.