controls
the movement of the turret cross-slide. The longitudinal feed is
disengaged when the flange has been turned, by an independent stop. This
machine has twelve longitudinal stops, there being one for each turret
face and six auxiliary stops, in addition to the stops for the
cross-slide.

[Illustration: Fig. 28. Tool Equipment for Turning Scroll Gear Blank on
Acme Flat Turret Lathe]

After roughing the flange, the turret carriage is locked or clamped
rigidly to the bed to prevent any lengthwise movement, and the back face
of the front flange is rough-turned by tool _B_ in to the diameter of
the hub which is indicated by a micrometer dial on the cross-feed screw.
The carriage is then unlocked and auxiliary stop No. 7 is engaged (by
turning a knob at the front of the slide) and the cylindrical hub is
turned back to the rear flange, the feed being disengaged by the
auxiliary stop just as the tool reaches the flange. The cross-slide is
now moved outward, longitudinal auxiliary stop No. 8 is engaged, the
turret slide is moved against the stop, the carriage is locked and the
front sides of both the front and rear flanges are rough-faced by tools
_B_ and _C_. The turret is next indexed and the hole rough-bored by
cutter _E_. After again indexing the turret, the hub and flanges are
finish-turned and faced by tools _F_ and _G_, as described for the
rough-turning operation. The final operation is that of finishing the
bore by cutter _H_.

[Illustration: Fig. 29. Acme Flat Turret Lathe Arranged for Turning
Roller Feed Body]

The operation shown in Fig. 29 is that of turning the body of a roller
feed mechanism for a turret lathe. The casting is held in a three-jaw
universal chuck and it is first rough-bored by tool _A_. The turret is
then indexed and the side of the body and end of the hub are rough-faced
by tools at _B_. The turret is again indexed for rough-turning the
outside of the hub and body, by tools _C_ and _D_. Similar tools _E_
and _F_ are then used to finish these same surfaces, after which the end
of the hub and side of the body are finished by tools _G_ and _H_
similar to those located at _B_. The final operation is that of
finishing the bore by tool _J_ and cutting a groove in the outside of
the hub by the bent tool _K_.

[Illustration: Fig. 30. Turret and Head of Jones & Lamson Double-spindle
Flat Turret Lathe]

=Double-spindle Flat Turret Lathe.=--The extent to which modern turning
machines have been