to the vertical motion of the needlebar. Remove
the needlebar connecting link by grasping it and
then withdrawing it from the face of the machine.
Balance Wheel Adjusting Screw
The balance- wheel adjusting screw (figure 4-11
[L]) eliminates end play in the balance wheel and
arm shaft. Remove the balance wheel adjustment
The balance wheel (figures 4-6 [R] and 4-11
[N]) transfers the motion and power from the one-
third-horsepower electric motor to the arm shaft.
To remove the balance wheel, you must first
loosen the two setscrews attaching it to the arm
shaft; then you withdraw it from the machine.
NOTE: The balance wheel is very fragile. Do
not hit it with a hammer to remove it.
Arm Shaft Connection Belt
The arm shaft connection belt (figure 4-4 [A])
transfers the power and motion from the arm
shaft connection belt pulley to the safety clutch
pulley. To remove the arm shaft connection belt,
you insert a small screwdriver along the left edge
and slide the belt from the safety clutch pulley.
Arm Shaft Connection Belt
Pulley Position Screw
The arm shaft connection belt pulley position
screw holds the pulley in a freed position. The arm
shaft connection belt pulley position screw is the
larger of the two screws on the pulley. The smaller
screw is a setscrew. It must be loosened but not
removed from the pulley. Remove the arm shaft
connection belt pulley position screw by unscrew-
NOTE: For machines with ball bearings, the
arm shaft arm bushing setscrews are located just
to the right of the connection belt pulley. They
secure the arm shaft bushing to the arm shaft.
These screws are not removed from the bushing;
however, they must be loosened for the arm shaft
to be removed.
The Presser-Lifting Eccentric
The presser-lifting eccentric supplies the
lift for the alternating presser feet. Free the
presser-lifting eccentric by loosening the two
presser-lifting eccentric setscrews located through
the opening in the rear of the arm (figure 4-11
[A]). You must rotate the balance wheel to loosen
the second screw. Be sure the eccentric rotates
freely on the shaft.
Feed Indicator Disc
The feed indicator disc shows the operator the
number of stitches per inch the machine is
sewing. It also allows the operator to set the
machine to sew a desired number of stitches per
inch. Loosen the feed indicator disc setscrew and
ensure the disc will rotate freely on the shaft.
The needlebar crank transfers the motion and
power from the arm shaft to the needlebar by the
needlebar driving stud. Do not remove the
needlebar crank from the arm shaft.
Needlebar Connecting Link Stud
The needlebar connecting link stud transfers
the motion and power from the needlebar crank
to the needlebar connecting link. Do not remove
the needlebar connecting link stud from the arm
Needlebar Crank Friction Washer
The needlebar crank friction washer acts as
a bearing surface between the needlebar crank and
the front arm shaft bushing. In some cases the
needlebar crank friction washer remains with the
machine upon removal of the arm shaft bushing.
If this occurs, insert the index finger in the arm
shaft recess and remove the washer.
NOTE: The operator must be especially
careful when assembling the machine to be
certain the needlebar crank friction washer is
r e t u r n e d t o t h e a r m s h a f t . A b s e n c e o f t he
needlebar crank friction washer will cause the
machine to bind.
The arm shaft (figure 4-11 ) acts as a
carrier for, and transfers the power and motion
to, the arm shaft connection belt pulley, the feed
indicator disc, the needlebar crank friction
4 - 24