Chapter 4:

Coordinate System

Upon successful completion of this lesson, you will be able to:



CNC motion is based on the Cartesian coordinate system. A CNC machine cannot be successfully operated without an understanding of the how coordinate systems are defined in CAM and CNC machine and how the systems work together.

This chapter begins with a review of the Cartesian coordinate system and then explains in detail how the coordinate systems between CAM and the CNC machine are related to each other. It also describes how the machine work coordinate system (WCS) is set on the CNC machine so the machine knows where the part is located within the work space.

It concludes with a discussion of tool length and diameter offsets. Length offsets are required to account for different tool lengths (how far a particular tool extends out of the holder). Diameter offsets are the key to highly precise machining where part tolerances can be maintained to an accuracy of .005 inches or less.