Automatic Control
Machine tools can be operated manually, or under automatic control. Early machines used flywheels to stabilize their motion and had complex systems of gears and levers to control the machine and the piece being worked on. Soon after World War II, the numerical control (NC) machine was developed. NC machines used a series of numbers punched on paper tape or punched cards to control their motion. In the 1960s, computers were added to give even more flexibility to the process. Such machines became known as computerized numerical control (CNC) machines. NC and CNC machines could precisely repeat sequences over and over, and could produce much more complex pieces than even the most skilled tool operators.
Before long, the machines could automatically change the specific cutting and shaping tools that were being used. For example, a drill machine might contain a magazine with a variety of drill bits for producing holes of various sizes. Previously, either machine operators would usually have to manually change the bit or move the work piece to another station to perform these different operations. The next logical step was to combine several different machine tools together, all under computer control. These are known as machining centers, and have dramatically changed the way parts are made.
From the simplest to the most complex, most machine tools are capable of at least partial self-replication, and produce machine parts as their primary function.
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Famous quotes containing the words automatic and/or control:
“What we learn for the sake of knowing, we hold; what we learn for the sake of accomplishing some ulterior end, we forget as soon as that end has been gained. This, too, is automatic action in the constitution of the mind itself, and it is fortunate and merciful that it is so, for otherwise our minds would be soon only rubbish-rooms.”
—Anna C. Brackett (18361911)
“Not being able to control events, I control myself; and I adapt myself to them, if they do not adapt themselves to me.”
—Michel de Montaigne (15331592)