TABLE OF CONTENTS In the last chapter, several lathe procedures described programming of a turning and boring tool path. A number of different techniques have been introduced, mainly describing the finishing tool path. Virtually no attention has yet been given to the removal of an excessive stock, in such operations as rough turning and rough boring. It is a subject in its own right and this chapter describes various methods of stock removal for roughing and finishing.
One of the most time consuming tasks in manual programming for a CNC lathe is the removal of an excessive stock, typically from a cylindrical material, known as rough turning or rough boring - or simply roughing.
To manually program a roughing tool path requires a series of coordinated rough passes, with one block of program for each tool motion. For roughing of a complex contour, such a method is extremely time consuming and very inefficient, as well as prone to errors. Some programmers try to sacrifice programming quality for speed, by leaving an uneven stock for finishing, causing the cutting tool to wear out prematurely. The surface roughness of the finished profile often suffers as well.
It is in the area of rough stock removal where the modern lathe controls are very useful and convenient. Almost all CNC lathe systems have a feature that allows the roughing tool path to be processed automatically, using special cycles. Roughing is not the only application for these cycles, there are also...
