CNC is simply a generic term for machinery whose movements are computer controlled vs manually controlled by a skilled operator. Computer Mumerical Controlled. In the early days of CNC, manually controlled milling (and other) machines were retrofitted with CNC technology to take advantage of the new developments in CAD design. Its basically servos and drives turning the knobs instead of an operator. Setting it up is still very much a skilled job and operating the machine still involves people...just different skill sets.
As an example, consider a stamped steel automobile fender. And we'll go only go back 45 years to make it simple. Craftsmen and artists would build a clay model of a car body. Designers would manually transfer those shapes to 2 dimensional drawings and add flanges, reinforcements, etc. to the product design drawings. For appearance critical items with complex shapes like body panels including fenders, wood models were built. Sheet wax was at times added to represent metal thickness if there was a need for two sided tools. A metal stamping die has two sides and you can't just ignore thickness. The dies were cut on large duplicating machines that traced the models and transferred the complex shapes to the stamping dies. Skilled machinists completed the dies by manually controlling mills, lathes, drills, etc. to cut the detail of flanges and other detail. Most stamped body panels take multiple steps (progressive dies) to form, trim, pierce and bend the steel. There was, and still is, both science and art involved in forming metal into shape without tears, wrinkles or other defects.
Today we design cars using CAD software, the 3D design exists as digital data.. We review designs using everything from basic viewing of a screen to virtual reality to holograms to 3D printed or NC cut models...sometimes full size, sometimes scaled down, sometimes foam, sometimes wood , sometimes even clay. We cut clay so if we don't like it we can modify it manually, laser scan the changes and feed that data back to CAD designers. When its all done, we have a complete 3D solid digital model of the fender we want to build. Software to analyze (finite elements analysis, FEA) and optimize the strength is possible because we have a digital model. The same is true for simulating, optimizing and analyzing the stamping process as well as everything from the shipping racks to the paint robot programs to the assembly process. For injection molded plastic parts we have the ability to predict, analyze and optimize flow inside the molds before they are built. The list goes on and on.
Getting back to CNC...Because we have a digital part design, the stamping dies can be built directly from the data...no models and wax and epoxy casts of models with wax...just convert the design data to machine programs and allow the machine movements to be controlled by computer.
For someone to be so bent on insisting we move the promotion of pool forward using social media and technology, it's completely inconsistent to talk about CNC the way he does. The environmental topic is complete nonsense. Nobody is making cues without a lathe. A factory that is machining cast engine blocks with a few modern high speed NC machine centers does the work of 100 manually operated 1960's era machines.
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