Reference positions used on CNC machine:
There are three reference positions on CNC machine:
1. Machine zero point
2. Work zero point
3. Tool home position
4.Reference point
1. Machine zero point: At this point coordinates of all axes are zero. Tool moves with respect to this point and position of all axes can be seen on computer screen. Machine zero point is decided by manufacturer of machine.
2. Work zero point: For preparing a program, first tool path is prepared according to operation sequence and then coordinates of all points are determined. These coordinates are determined by considering an original point on the job where all the axes intersect and coordinates of that point are zero. This original point is known as work zero point.
3. Tool home position: Tool is placed away from work zero point as well as machine zero point for sake of safety of tool, job and machine. The tool is changed only at home position.
4. Reference point: A position in the machine working area which is determined exactly by limit switches. The slide positions are reported to the control by the slides approaching.