HIGHLEAD GC20618 Series, Instruction Manual Parts Catalog

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10
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e) After the adjustment, tighten the feed bar set screw.
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The feed dog height is factory-adjusted to 1.2mm
14
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Relationship between rotating hook
motion and take-up lever motion
When the timing belt (toothed belt) was removed for
its replacement, for example, the relationship between
rotating hook motion and take-up lever motion should
be adjusted as follows:
a) Turn the balance wheel and stop when the take-up
lever is lifted to its upper dead point.
b) Lean the machine head backward and make sure the arrow (timing mark) put on the timing belt is in
line with the black line on the boss of lower shaft bearing.
c) If the timing mark is not in line with the black line ,remove the timing belt and install it again to
adjust.
15
．
Relationship between hook motion
and opener motion
a) Turn the balance wheel by hand and stop when
the opener holder is located most remotely from
the throat plate.
b) Make sure gap between the bobbin case holder A
and the opener is approximately 0.2mm.
c) If the gap is too large or small , loosen the opener
holder set screw B and adjust position of the opener.
16
．
Relationship between needle motion and feed dog motion
a) Set feed length to “0” on the feed setting dial
b) Lean the machine head backward.
c) Loosen the feed lifting rock shaft crank set screws A and B
d) Set the needle at the lowest position.
e) Adjust the distance between presser rod and vibration
prevention rod to 9mm and temporarily tighten the feed
lifting rock shaft crank set screws A and B
f) Check that the right feed lifting rock shaft crank is
connected with the link at right angle, as shown in Figure.
g) If the connection is not at right angle, remove the back
cover, loosen screw C and move the right link to connect
the right feed lifting rock shaft with the link at right angle.