The cutting tool and the work are located at certain positions in NC machine. During the machining, they are moved from their positions with relation to each other. The system involved in moving the cutting tool and the work is known as motion control system.
Point – to – Point Motion Control System
It is a system in which the cutting tool is located at a particular point in relation to the work. Machining is performed only after the cutting tool and the work are located at defined positions and there will not be any change in their positions during machining. This system is also called positioning system for this reason. When machining at the particular position is over, the cutting tool (or) the work (or) both are moved to be relocated to different points for subsequent machining. The relocation is achieved by their movement in two main axes (x axis and y axis). This is the reason for this system to be called as point – to – point system. The NC machines with point to point system are simple in construction and are cheaper. They are adapted for drilling machines, jig boring machines and spot welding machines.
Continuous Path Motion Control System
In this system, both the cutting tool and the work change their positions during machining. The movement of the cutting tool and the work is simultaneous in all axes and in all planes each at different speed. This system is also called as contouring system and is mainly used in milling machine.