CNC machining and RP process are two advanced processing methods for prototypes. However, there are many differences between them.
The entire prototyping process of the RP methods is controlled by machines and their software. It is efficient without much human input, and models are created quickly and predictably. They can be operated in an office environment, as they are 'clean' in their processes, without generating dust, particles and waste typical in CNC machining. Therefore, most companies in the U.S. prefer the use of these modern RP methods in creating prototypes.
CNC machining, on the other hand, is a more traditional prototyping method. It requires plenty of care and expertise in order to create good prototypes. Factors like CAM programming- such as the types of milling bits to use, travel and spindle speed for cutting different materials, methods to reach undercuts and various other issues have to be controlled by experienced machinists and programmers with years of training specific to
CNC prototyping.
Along with the transfer of most production and assembly of consumer and industrial products to countries with lower labor costs, the tool and die industry which supplies CAM programmers and machinists is gradually dwindling. This is perhaps the main reason for the shortage of CNC machining in America.
