Page 81 - Turner 1st sem Practicals

Job sequence

Mounting chucks • Turn the spindle by hand until the clearance holes on
the spindle align with the cam lock studs on the chuck.
• Switch off the motor.
• Set the speed change lever to the lowest rpm.
• Place the chuck on the wooden blank and slide it close
to the spindle nose. • Push the chuck on to the spindle.
• Turn the spindle anticlockwise by hand and engage the • Tighten each cam lock screw in a clockwise direction.
chcuk on the spindle.
Bolted spindle
• Set the speed change lever to the low rpm.
• Remove the nuts and washer from the studs on the
• Screw the chuck until it fits firmly on the spindle. chuck.

• The chuck should easily screw into the spindle. • Disengage the clutch to permit free rotation of the
spindle.
Dismounting chucks
• Turn the spindle by hand until the key in the spindle
• Switch off the motor.
lines up with the slot in the chuck.
• Set the speed change lever to the lowest rpm.
• Set the speed change lever to the lowest rpm.
• Place a wooden block between one of the chuck jaws • Push the chuck on to the spindle.
and the rear of the lathe bed.
• Fit washer and nuts to the studs.
• The length of the wooden block should be slightly less
than the bottom of the chuck of the lathe. Taper spindle

• Turn the lathe spindle clockwise by hand to loosen the • Turn the spindle by hand until the key on the spindle
chuck from the spindle nose. nose lines up with the keyway in the chuck.

• Unscrew the chuck from the spindle. • Set the speed change lever to the lowest rpm.
• Remove the wooden block. • Push the chuck on to the spindle.

Note • Turn the locking ring anticlockwise.
Cam lock spindle • Engage the special 'C' spanner on the locking ring.
• Disengage the clutch to permit free rotation of the • The spanner should fit around the top of the locking ring
spindle.
with the handle pointing downwards
• Insert the correct chuck key into a cam locking screw • Grip the end of the handle with one hand.
on the spindle.
• Firmly strike the other end with the other hand in an
• Turn each cam locking screw so that the registration anticlockwise direction.
line is vertical with the corresponding line on the
spindle. • Securely tighten the locking ring.

Skill sequence

Mounting and dismounting of chucks

Objective: This shall help you to
• mount and dismount chucks from spindle noses.
To perform lathe operations on work materials, it may not When mounting a chuck on the headstock spindle, exercise
be always possible to have only one type work-holding care to prevent damage occuring to the chuck or spindle.
device fitted to the spindle. Hence it becomes an absolute
necessity for dismounting the work-holding device already Damage may reduce the accuracy of the lathe. The points
assembled to the spindle and mount the work-holding set out below are important and should be followed.
device which is needed for the work in hand. Before mounting
For an easy understanding of different spindle noses and Before attempting to mount a chuck, ensure that it is the
their applications, the mounting of different work-holding correct one for the lathe and for the job in hand.
devices are illustrated.
Producltion & Manufacturing : Turner - Exercise 1.3.24 69