ds at the back of the machine.

[Illustration: Fig. 37. Plate on the Headstock of Machine Illustrated in
Fig. 32 giving the Speeds and Feeds]

Next we have to determine on which faces of the turret to place the
different tools. Each turret face is numbered to agree with the
corresponding feed cam on the drum. The speed and feed plate (Fig. 37)
gives the various feeds obtainable per revolution of the spindle. As
will be seen, the different cams give different feeds. Cam No. 1 has a
coarse feed suitable for roughing; cam No. 2 a finer feed adapted to
finishing, and so on. Since the first operation consists in
rough-turning, cam No. 1 is used. Cam No. 2, which gives a finer feed,
is used for the finish-turning operation. Cam No. 4, which is ordinarily
used for reaming, could, in this case, be used for recessing, as this
recess is for clearance only and may be bored with a coarse feed.

The final operation, which is that of facing, can be done with any cam
and cam No. 5 may be used. It will be understood that for facing
operations, the feeds given do not apply. As the roll passes over the
point of the feed cam at the extreme end of the movement, the feed of
the turret slide is gradually slowed down to zero; since the facing
takes place in the last eighth or sixteenth inch of this movement, it is
done at a feed which is gradually reduced to zero. This is, of course,
as it should be, and it is not necessary to pay any attention to the
tabulated feeds in facing operations.

=Setting the Turret Slide.=--The next adjustment is that of setting the
turret slide. In making this adjustment the turret is set in such
relation to the work that the tools will have but a small amount of
overhang, the cam-shaft being revolved by hand until the cam-roll is at
the extreme top of the forward feeding cam, so that the turret slide is
at the extreme of its forward movement. When this adjustment has been
made by the means provided, set the turret index tripping dog so as to
revolve the turret at the proper point. After a turning tool-holder and
tool is attached to the face of the turret, cam No. 1 is placed in its
operating position and is revolved by hand until the roll is on the
point of the cam and the turret at the forward extreme of its motion. At
this point the tool-holder is set so that the cutter will be far enough
forward to complete its turning operation. The feed cam is then turned
backward, thus returning the turret slide, and the