LATHE OPERATIONS - OD1645 - LESSON 1/TASK 1
2 The length of the work need not be considered because once the
taper attachment has been set, that particular taper will be turned on any
piece of any length.
3 The alignment of the lathe need not be disturbed, thus saving
considerable time and effort.
4 Taper boring can be accomplished as easily as taper turning.
5 A much wider range is possible than by the offset method.
For
example, to machine a 3/4 inch per foot taper on the end of bar 4 feet long
would require an offset of 1 1/2 inches, which is beyond the capabilities of
a regular lathe but can be accomplished by the use of the taper attachment.
(b) Some engine lathes are equipped with a taper attachment as standard
equipment and most lathe manufacturers have a taper attachment available.
Taper turning with a taper attachment, although generally limited to a taper
of 3 inches per foot and to set the length of 12 to 24 inches, affords the
most accurate means for turning or boring tapers.
The taper can be set
directly on the taper attachment either in inches per foot, or (on some
attachments) in degrees.
(c) Ordinarily when the lathe centers are in line, the work is turned
straight, because as the carriage feeds along, the tool is always the same
distance from the centerline.
The purpose of the taper attachment is to
make it possible to keep the lathe centers in line, by freeing the cross-
slide and then guiding it (and the tool bit) gradually away from the
centerline (figure 31, view A, on page 72). Also, by guiding it gradually
nearer the centerline (figure 31, view B), a taper hole can be bored.
(d) A typical taper attachment for the lathe is illustrated in figure
31. A bed bracket is attached to the lathe bed and keeps the angle plate
from moving to the left or to the right. The carriage bracket moves along
the underside of the angle plate in a dovetail and keeps the angle plate
from moving in or out on the bed bracket.
The taper to be cut is set by
placing the guide bar, which clamps to the angle plate, at an angle to the
ways of the lathe bed. Graduations on one or
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