5-20
4) Relationship between Needle and Hook
①
Adjusting Timing between Needle and Hook
Default timing of the needle and the hook is set by the main shaft angle of 200° and varies as below.
②
Adjusting Gap between Needle and Hook Point
•
Gap between the hook point and the scarf of the needle
should be 0.1
∼
0.3 mm minimum.
•
Thread skip occurs due to thread looping or inadequate
balance/gap between the needle and the hook. The closer
the hook point is to the needle, the hook point will be
inside the loop and threading will be more stable.
[Fig.5-29]
[Fig.5-31]
Hook point
0.1~0.3mm
[Fig.5-30]
Top point of hook
circumference
Top edge of
needle eye
Needle tip
Top edge of the needle eye
Hook allowance
(gap)
Hook point
Lower dead stop
of the needle
Hook point
a. At lower dead stop of the needle bar
2.3
3.7 mm
1.8
2.2 mm
0.5
1.5 mm
The figures may change according
to needle specification/number.
b. At needle-hook timing
c. At needle-hook timing
[CAUTION]
The hook can move right and left if there is an allowance in
the lower shaft gear. Eliminate the allowance (gap) by
turning the hook clockwise. Then adjust the timing.
