Both types of CNC machines, machining centers and lathes, use spindle rotation when removing excessive mate-rial from a part. The rotation may be that of the cutting tool (milling) or the part itself (lathes). In both cases, the activi-ties of the machine spindle and the working feedrate of the cutting tool need to be strictly controlled by the program. These CNC machines require instructions that relate to the selection of a suitable speed of the machine spindle and a cutting feedrate for a given job.
