CNC machining offers some important benefits over more traditional manual machining. CNC gives a level of precision, control and consistency that would be virtually impossible to achieve with a human operator machining by hand.
With manual machining, the machinist must manipulate the cutting tool and/or work-piece by hand in order to produce the desired result. This takes great skill, but it also takes a lot of time and intense concentration. A machinist can only work on one piece at a time and the work can only proceed as fast as they are able to cope with it. A momentary lapse in concentration could result in an error which may require a damaged work-piece to be discarded.
With CNC machining, the operator’s involvement in the actual machining process is minimal. The machine can be left largely unattended once the work-piece is inserted and the program has started running. A CNC operator could potentially supervise several CNC machines running in parallel, giving obvious benefits in terms of efficiency.
Perhaps the greatest benefit of CNC machining over manual machining is consistency. A CNC machine will follow the steps of a program exactly, and a program can be run again and again. This means it is possible to create multiple identical components, confident that each will have exactly the same measurements and finish as all the others. It’s simply not possible for a human machinist, even a highly skilled one, to produce the kind of consistent accuracy needed for many precision engineering applications.
Because of the programmable nature of CNC machines it is relatively easy to change from producing one work-piece to another one. It’ is simply a case of loading a different program. Making modifications to a component requires only that you modify the program, and the program itself can be stored and re-used at a later date. This enables fast turnaround between different products, and also makes just-in-time production viable. If a replacement piece is needed, the program can be loaded and a new object machined, negating the need for a large stock of machined components.
As can be seen there are considerable benefits to CNC machining, especially where multiple identical copies of an object need to be produced.