CHAPTER LEARNING OBJECTIVES
Upon completing this chapter, you should be able to do the following:
Describe and explain the use of engine lathes.
Explain engine lathe setup.
Describe and explain engine lathe operations.
Describe and explain methods of taper turning.
Describe and explain cutting screw threads on an engine lathe.
There are several types of lathes installed in
is determined by two measurements: (1) either the
diameter of work it will swing over the bed or the
shipboard machine shops, including the engine lathe,
horizontal turret lathe, vertical turret lathe, and
diameter of work it will swing over the cross-slide
several variations of the basic engine lathe, such as
and (2) either the length of the bed or the maximum
bench and gap lathes. All lathes, except the vertical
distance between centers. For example, a 14-inch by
turret type, have one thing in common for all usual
6-foot lathe has a bed that is 6 feet long and will swing
machining operations--the workpiece is held and
work (over the bed) up to 14 inches in diameter.
rotated around a horizontal axis while being formed to
Engine lathes range in size from small bench
size and shape by a cutting tool. In a vertical turret
lathes with a swing of 9 inches to very large lathes for
lathe, the workpiece is rotated around a vertical axis.
turning work of large diameters, such as low-pressure
turbine rotors. A 16-inch swing lathe is a good,
Horizontal lathes, as well as many of their
average size for general purposes and is usually the
attachments, and their operation are described in this
size installed in ships that have only one lathe.
To learn the operation of a lathe, you must be
familiar with the names and functions of the principal
parts. In studying the principal parts in detail,
An engine lathe similar to the one shown in
remember that lathes all provide the same general
figure 6-1 is found in every machine shop. It is used
functions even though the design may differ among
mainly for turning, boring, facing, and screw cutting,
manufacturers. As you read the description of each
part, find its location on the lathe pictured in figure
grinding, spinning, and spring winding. The work
6-1. For specific details on a given lathe, refer to the
held in an engine lathe can be rotated at any one of a
manufacturer's technical manual for that machine.
number of different speeds. The cutting tool can be
accurately controlled by hand or power for
longitudinal feed and cross-feed. (Longitudinal feed
BED AND WAYS
is the movement of the cutting tool parallel to the axis
of the lathe; cross-feed is the movement of the cutting
The bed is the base for the working parts of the
tool perpendicular to the axis of the lathe.)
lathe. The main feature of the bed is the ways, which
are formed on its upper surface and run the full length
Lathe size is determined by various methods,
of the bed. The tailstock and carriage slide on the
depending upon the manufacturer. Generally, the size