JUKI LH-4500C Series Instruction Manual page 114

Common
❾
❽
・ Determining the hook position
1) Place the sewing machine in the hook timing adjustment mode.
Loosen lower shaft set collar clamping screw  and hook driving shaft saddle setscrews  and  .
2)
Turn the handwheel counterclockwise to lift the needle bar 2.2 mm from its lowest point. (The nee-
dle bar goes up by 2.2 mm by advancing the angle value shown on the main shaft rotating angle
display on the operation panel at the time the needle bar is at its lowest point.)
In the aforementioned state 2), align blade point of hook ❽ with the center of needle ❾ , and adjust
3)
so that a clearance of 0.01 to 0.05 mm (for the F type model) or to 0.03 to 0.1 mm (for the G type
model) is provided between the blade point of hook and the needle by adjusting the position of the
hook driving shaft saddle to the right and left. Then, fix setscrews  and  , and tighten lower
shaft set collar clamping screw  .
At this time, the distance from the blade point of hook and the upper end of needle eyelet becomes
1.2 mm. (The lower shaft set collar must be aligned with the end faces of lower shafts C and D.)
The hook driving
shaft setting collar
is aligned with the
end face of hook
driving shaft D


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Hook driving shaft
setting collar
Left hook
Hook driving shaft setting collar
Hook driving shaft C
The hook driving shaft setting
collar is aligned with the end face
of hook driving shaft C
Right hook
Hook driving shaft D