1.2 Conventional vs. CNC Machine Tool
Machine Structure
The CNC machine tools are basically built in the same way as conventional machine tools. The difference
lies in the fact that the machine components relevant for turning and milling processes are controlled by
computers.
The movement directions of the components of a CNC controlled machine tool are specified by a coordinate
system, which refers to the work part to be machined and shows axes located parallel to the main linear
movement. The movements necessary for machining the individual machine tool assemblies (table, turret
and others) are calculated, controlled and tested by a computer. For this purpose each machining direction
has a separate measuring system to calculate the corresponding positions of the machine tool assemblies
and to return this information to the control.
Function
In the following overview conventional, NC and CNC machine tools are compared in their basic functionality: