Computer numerical control: Difference between revisions

Revision as of 01:28, 7 May 2005

Revision as of 01:32, 7 May 2005

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==Historical notes==

The need of the U.S. Air Force for templates more precise than could be doneobtained by methods representative of the state of the art in the late 1940s inspired a gentlemen by the name of John Parsons, President of the Parsons Works of Traverse City, Michigan, to propose that a by-the-numbers technique commonly used in machining be put under servo control with position data generated by a computer (in order to have many more points that would defy the practicability of hand calculations). His concept was to machine to setpoints as guides for subsequent manual finishing, that is, to speed up a manual process so more points could be included.

His project was taken over by the Servo Mechanisms Laboratory of the Massachusetts Institute of Technology and redefined as interpolated position control that has the cutting tool traverse a straight line between points at a prescribed rate of travel. Thus, the tool would be constantly on the programmed contour and not spending most of its time making non-cutting moves.