Overview

In the CNC world, point coordinates are the key to develop a program using any type of available motion. The single purpose of coordinates is to define a point, then use various motion commands to connect two or more points and develop a unique toolpath. While the word coordinate is heard almost daily, it still does not hurt to look at its definition, which is quite simple:

A coordinate is any set of two or more numbers that determine the position of a point with respect to established references

A reference position is a fixed position, such as machine zero (machine origin) or a part zero (part origin). Mathematically, there are four types of coordinates:

• Rectangular Coordinates

• Polar Coordinates

• Cylindrical coordinates

• Spherical Coordinates

All four types are used in CNC applications, for different machines and different kinds of work. Without a doubt, rectangular coordinates are the bread and butter of CNC programming for machining centers, lathes, wire EDM, laser cutters, and a dozen of other machine tools. Polar coordinates are very common on non-Fanuc controls, mainly because they are standard feature. Fanuc offers polar coordinates only as a special control option, which is unfortunate, considering their many applications advantages that all users could benefit from. The remaining two coordinate systems cylindrical and spherical are not supported by the majority of controls and those controls that do support these coordinate methods offer them as optional features. In this case, the option offer is justified, because neither cylindrical...