LATHE OPERATIONS - OD1645 - LESSON 1/TASK 1
being machined between centers. However, it can also be used to hold live
centers, tapered shank drills, reamers, and drill chucks.
The tailstock
moves on the ways along the length of the bed to accommodate work of varying
lengths.
It can be clamped in the desired position by the tailstock
clamping nut.
(b) The dead center is held in a tapered hole (bored to a Morse taper)
in the tailstock spindle.
The spindle is moved back and forth in the
tailstock barrel for longitudinal adjustment. The handwheel is turned which
turns the spindle-adjusting screw in a tapped hole in the spindle.
The
spindle is kept from revolving by a key that fits a spline, or keyway, cut
along the bottom of the spindle.
(c) The tailstock body is made in two parts. The bottom, or base, is
fitted to the ways; the top can move laterally on its base.
The lateral
movement can be closely adjusted by setscrews. Zero marks inscribed on the
base and top indicate the center position and provide a way to measure
setover for taper turning.
(d) Before inserting a dead center, a drill, or a reamer into the
spindle, carefully clean the tapered shank and wipe out the tapered hole of
the spindle. After a drill or reamer is placed into the tapered hole of the
spindle, make sure that the tool will not turn or revolve. If the tool is
allowed to revolve, it will score the tapered hole and destroy its accuracy.
The spindle of the tailstock is engraved with graduations which help in
determining the depth of a cut when a piece is drilled or reamed.
(5) Carriage.
(a) The carriage carries the crossfeed slide and the compound rest which
in turn carries the cutting tool in the toolpost. The carriage slides on
the ways along the bed (figure 6 on page 14).
(b) Figure 6, view B, shows a top view of the carriage. The wings of
the H-shaped saddle contain the bearing surfaces which are fitted to the V-
ways of the bed.
The cross piece is machined to form a dovetail for the
crossfeed slide. The crossfeed slide is closely fitted to the dovetail and
has a tapered gib which fits between the carriage
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