TABLE OF CONTENTS It is much easier to calculate the absolute XY coordinates for a simple contour, such as a rectangle, but it is much harder to calculate points where the contour includes angles and partial radiuses. These parts are usually programmed with the assistance of a CAD/CAM system (CAM), but if such system is not available or in other situations, the CNC programmer must resort to the old fashion way, by using a pocket calculator. Most calculations will be using trigonometric functions, but knowing the basic arithmetic and algebraic operations, knowing formulas, being familiar with solving triangles is still the major requirement. This chapter will present some techniques that have proven to be suitable for solving a majority of problems associated with calculation of more difficult contour points.
Any tool can only be used correctly if the user has a sufficient amount of knowledge about the purpose of the tool and how to use such a tool. In CNC manual programming, we are talking about three major tools pencil, paper, and a calculator. An old cartoon has also shown a fourth tool a very large eraser. Of course, in these days, pencil is most likely replaced by a text editor (even Windows Notepad will do in an emergency), and actual printing on paper is not always necessary, as the program can be transferred to the control system via a cable, using DNC software. Eraser is part of the editor, and Windows even provide a simple calculator. In practice, a physical...
