only the main turret, you can machine a workpiece as
use an electric drive controlled by a lever. When you
large as 44 inches in diameter.
move the feed control lever to the creep position, the
The main difference between the vertical turret
turret head moves in the direction selected in
lathe and the horizontal turret lathe is in the design
increments as low as 0.0001 inch per minute. This
and operating features of the main turret head.
creep feed is independent of table revolution and can
be made with the table stopped.
mounted on a swivel plate (3) which is attached to
An attachment available on some machines
the saddle (4). The swivel plate allows the turret
permits threading of up to 32 threads per inch with
slide to be swung up to 45 to the right or left of the
a single-point tool. The gears, as specified by the
vertical, depending on the machine model. The
lathe manufacturer, are positioned in the attachment
saddle is carried on, and can traverse, the main rails
to provide a given ratio between the revolutions per
(5). The main rails are gibbed and geared to the
minute of the table and the rate of advance of the
upright bedways (6) for vertical movement. This
tool.
arrangement allows you to feed main turret tools
either vertically or horizontally, as compared to one
The same attachment also lets the operator turn or
direction on the horizontal turret lathe. Also, you
bore an angle of 1 to 45 in any quadrant by
can cut tapers by setting the turret slide at a suitable
positioning certain gears in the gear train. You can
angle.
then engage the correct feed lever to cut the angle.
Later in this chapter, we'll explain in detail how you
The side turret and side head of the vertical turret
turn tapers on a vertical turret lathe without this
lathe correspond to the square turret and cross slide of
attachment.
the horizontal turret lathe. A typical vertical turret
lathe has a system of feed trips and stops that
functions similarly to those on a horizontal turret
VERTICAL TURRET LATHE TOOLING
lathe. I n addition, the machine has feed
disengagement devices to prevent the heads from
The principles used to operate a vertical turret
going beyond safe maximum limits and bumping into
lathe are not very different from those for a horizontal
each other.
turret lathe. The only significant difference is in the
Vertical turret lathes have varying degrees of
main turret. We said earlier that the main head
capabilities, including feed and speed ranges,
corresponds to the hexagonal turret of the horizontal
angular turning limits, and special features such as
machine. You can feed it vertically toward the
threading.
headstock (down), horizontally, or at an angle. To
do this, you can engage both the horizontal and
You can expect to find a more coarse minimum
vertical feeds, or you can set the turret slide at an
feed on the earlier models of vertical turret lathes.
angle from the vertical and use only the vertical
Some models have a minimum of 0.008 inch per
feed.
revolution of the table or chuck, while other models
will go as low as 0.001 inch per revolution. The
The tool angles used for the cutters of the vertical
maximum feeds obtainable vary considerably also;
machine correspond to those on the horizontal turret
however, this is usually less of a limiting factor in job
lathe; they are an important factor in successful
cutting. It is equally important to set cutters on center
setup and completion.
and maintain the clearance and rake angles in the
The speeds on any given vertical turret lathe tend
process. Again, you must be sure the cutters are held
to be much slower than those on a horizontal lathe.
rigidly.
This reduction in speed is often required because of
the large and oddly shaped sizes of work done on
In vertical turret lathe work, you must often use
offset or bent-shank cutters, special sweep tools, and
vertical turret lathes. A high speed can throw a
forming tools, particularly when you machine
workpiece out of the machine that may damage
equipment and injure personnel.
odd-shaped pieces. Many such cutting tools are
designed to take advantage of the great flexibility of
One of the major differences between the lathes
operation provided in the main head.
On a repair ship, you normally will use the
use to position the cutter to the work. On the lathe in
vertical turret lathe for jobs other than straight
8-3