The Early History Of Cnc Precision Engineering
Saturday, August 29th, 2009Machines used as tools became automated and the history of automation in cnc precision machining begins when machines that could control tools were developed as it were from the cuckoo clock to the computerized numerical control machining. Producing a product using manually built machines was the early development of computerized numerical control machines that could be abstractly programmed to produce a machine that could produce a product.
In the 1800′s, inventors Thomas Blanchard and Christopher Miner Spencer developed lathes, which were an innovation from the cam technology that had been used in music boxes and cuckoo clocks. The work of Jacquard Loom and Charles Babbage in mechanical computers being abstractly programmed was a reality in the 1800′s but their work was not picked up by the machine tool industry.
Applying hydraulics to tracing templates using a stylus, which helped industrialize automation, developed machines like the Pratt and Whitney “Keller Machine”. Capturing the manual movements of a machinist on a machine and playing those movements back on command by a machine was a method invented by General Motors in the 1950′s.
The problem with developing a computerized numerical control machine was in the degree of reliability in the reading by the machine of the abstract code. The invention of the Servo, which gave right measurement information, solved that problem.
A Selsyn was made by the performance of two servos. A Selsyn could be read by a variety of mechanical and electrical systems to ensure that the right information had been transferred in their products.
The suggestions that Selsyn could be used in machining control came from a Swedish immigrant, Ernst F. W. Alexanderson who was employed by General Electric. General Electric used Alexanderson’s mechanical computer that amplified torque letting big motors to be run by little force in their gun laying system for the United States Navy ships.
However, the efforts of trying to make a helicopter propeller by John T. Parsons in 1942 credited him as the father of the numerical control machine. In an effort to get MIT suggestions on his punch card input machine, Parsons turned to MIT who took his invention and left him out of production, greatly surprising Parsons..
Using computer control, punch tapes made on the Whirlwind were made by John Runyon. A uniform “programming” language for numerical control introducing computerized numerical control was proposed in June 1956, by the Air Force.

