-36-
Model G0740 (Mfg. Since 11/12)
Figure 38. 4-jaw tightening sequence.
1
2
3
4
Workpiece
Center Point
Figure 39. Generic picture of non-cylindrical
workpiece correctly mounted on the 4-jaw chuck.
4-Jaw Chuck
Refer to the prior Chuck Installation and Chuck
Removal
sections for instructions on installing or
removing the 4-jaw chuck.
The 4-jaw chuck features independently adjust-
able hardened steel jaws for holding non-con-
centric or off-center workpieces. Each jaw can
be independently removed from the chuck body
and reversed for a wide range of work holding
versatility.
Because of the dynamic forces involved in
machining a non-concentric or off-center
workpiece, always use a low spindle speed
to reduce risk of the workpiece coming loose
and being thrown from the lathe, which could
cause death or serious personal injury.
DISCONNECT LATHE FROM POWER!
Place a chuck cradle or plywood on the bed-
way below the chuck to protect the bedway
surfaces.
Use the chuck key to open each jaw so the
workpiece will lay flat against the chuck face,
jaw steps, or into the spindle opening.
With help from another person or a holding
device, position the workpiece so it is cen-
5. Tighten each jaw in small increments. After
you have adjusted the first jaw, continue
tightening the remaining jaws in an opposing
sequence, as shown by the sequential order
6. After the workpiece is held in place by the
jaws, use a dial indicator to make sure the
workpiece is centered in the chuck.
— If the workpiece is not correctly centered,
make fine adjustments by slightly loosening
one jaw and tightening the opposing jaw
until the workpiece is correctly positioned
(see the Figure below for an example).
