TABLE OF CONTENTS Produce, with a cutting action, surfaces of rotation (surfaces having a round or partly-round cross section), both external and internal, in a workpiece. The workpiece is rotated in a lathe, screw machine, or chucking machine. It is held between centers or in a chuck or collet, or fastened to a face place. The cutting tool is fed into the work or along the work, or both, to produce a part of the desired shape. There are several basic types of lathes and related machines as described below and many varieties of tools that can be fed against the workpiece. These machines are used extensively in the production of parts that contain surfaces of rotation. The basic operations performed on lathes are the following:
Is the most prevalent lathe operation. In its most common form, a single-point cutting tool is moved on a precise path with respect to a rotating workpiece. When the tool moves parallel to the axis of rotation, straight turning takes place and the surface machined is cylindrical or part of a cylinder. When the cutting tool moves uniformly closer or farther from the axis of rotation as it moves longitudinally, a tapered surface is generated. (This is often accomplished in engine lathe by moving the tailstock supporting center for the work to an off-center position, out of alignment with the headstock axis of rotation.) Fig. 3A1 shows examples of straight and tapered turning. Engine...
