HIGHLEAD GC20618 Series, Instruction Manual Parts Catalog

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21
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Installation of movable knife
(1)
Installation of movable knife
a. Turn the balance wheel and lower the needle bar to the lowest position.
b. Push the cam follower crank so that the cam roller enters into the thread trimmer cam groove.
c. Turn the balance wheel until the black mark point on the arm meets the white mark point on the
balance wheel. Set the cam follower crank at this position with a screwdriver temporarily preventing
the cam roller coming out from the cam groove.
d. Loosen the thread trimmer rocking crank clamp bolts A and B.
e. Adjust the movable knife so that the movable knife end slant portion protrudes
0-0.5 mm from the fixed knife, as shown in Figure and tighten the bolts A and B.
(2)
Gap between movable knife and bobbin case holder stopper
a
．
Turn the balance wheel by hand until needle reaches the
Lowest position.
b
．
With the needle at the lowest position, depress cam follower
crank, turn the balance wheel until the movable knife reaches
the extremity of its stroke.
c
．
Manually rotate the inner hook in the direction indicated by
arrow in Figure and adjust gap between the movable knife
and the inner hook stopper to about 0.5 mm (the screws A and B should be loosened for this
adjustment).
22.
Adjustment of thread trimmer cam
a
．
Turn the balance wheel by hand until the needles reach the lowest position.
b
．
Maintaining the needle position, depress the cam follower crank and put the cam roller into the
groove of thread trimmer cam.
c
．
Turning the balance wheel by hand, adjust the thread trimmer cam so that the movable knife starts
moving when the green mark point on the balance wheel comes in line with the black mark point on