Machinery Repairman

Figure 6-29.—Center rest.
To provide an intermediate support or rest for
long slender bars or shafts being machined
between centers. It prevents them from
springing due to cutting pressure or sagging as
a result of their otherwise unsupported weight.
To support and provide a center bearing for one
end of work, such as a spindle, being bored or
drilled from the end when it is too long to be
supported by the chuck alone. The center rest,
kept aligned by the ways, can be clamped at
any desired position along the bed, as
illustrated in figure 6-29. It is important that
the jaws (A) be carefully adjusted to allow the
work (B) to turn freely and at the same time
keep it accurately centered on the axis of the
lathe. The top half of the frame is hinged at C
to make it easier to place the center rest in
position without removing the work from the
centers or changing the position of the jaws.
FOLLOWER REST
The follower rest is used to back up work of small
diameter to keep it from springing under the pressure
of cutting. This rest gets its name because it follows
the cutting tool along the work As shown in figure 6-30,
it is attached directly to the saddle by bolts (B). The
adjustable jaws bear directly on the finished diameter
of the work opposite and above the cutting tool.
TAPER ATTACHMENT
The taper attachment, illustrated in figure 6-31, is
used for turning and boring tapers. It is bolted to the
back of the carriage saddle. In operation, it is
connected to the cross-slide so that it moves the cross
slide laterally as the carriage moves longitudinally,
thereby causing the cutting tool to move at an angle to
the axis of the work to produce a taper.
Figure 6-30.—Follower rest. Figure 6-31.—A taper attachment.
6-17