LATHE OPERATIONS - OD1645 - LESSON 1/TASK 1
the workpieces that can be supported.
The step chuck machine collets are
furnished blank and machined on the lathe to the desired step diameter.
(10) Lathe Tailstock Chuck. The lathe tailstock chuck is a device designed
to support the ends of the workpieces in the tailstock when a lathe center
cannot be conveniently used.
The chuck has a taper arbor that fits the
lathe tailstock spindle. The three bronze self-centering jaws of the chuck
will accurately close upon the workpieces that are between 1/4 and 1 inch in
diameter. The bronze jaws provide a good bearing surface for the workpiece.
The jaws are adjusted to the diameter of the workpiece and then locked in
place.
b.
Lathe Faceplates.
(1) A lathe faceplate (figure 17 on the following page) is a flat, round
plate that threads to the headstock spindle of the lathe. The faceplate is
used for clamping and machining irregularly-shaped workpieces that cannot be
successfully held by chucks or mounted between centers.
The workpiece is
either attached to the faceplate using angle plates or brackets, or is
bolted directly to the plate.
Radial T-slots in the faceplate surface
facilitate mounting workpieces.
The faceplate is valuable for mounting
workpieces in which an eccentric hole or projection is to be machined. The
number of applications of the faceplate depends upon the ingenuity of the
machinist.
(2) A small faceplate, known as a driving faceplate, is used to drive the
lathe dog for workpieces mounted between centers.
The driving faceplate
usually has fewer T-slots than the larger faceplates. When the workpiece is
supported between centers, a lathe dog is fastened to the workpiece and
engaged in a slot of the driving faceplate.
c.
Lathe Centers.
(1) General.
Lathe centers (figure 18 on page 39) are the most common
devices for supporting workpieces in a lathe.
Most lathe centers have a
tapered point with a 600 included angle to fit the workpiece holes with the
same angle. The workpiece is supported between two centers, one in the
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