-11-
2 2 . R e m o v i n g a n d i n s t a l l i n g t h e r o t a t i n g h o o k ( F i g . 2 7 )
2 Adjusting rotating hook point timing with
needle.
The motive relation between rotating hook and
needle affects the sewing quality. Standard timing
relation is : turn the balance wheel to locate needle
bar to its lowest position, and lift back 2.5mm the
rotating hook point (D) should be coincides with
needle center line (C), and hook point (D) is 1.2mm
above the upper edge (E) of needle eye.
When adjusting the rotating hook point timing
also to note the clearance between notch bottom of
needle (D) and hook point (C) of approx 0.05min
must be maintained. (Fig.26)
Lift the needle bar to its highest position, remove
the throat plate, take down the needle and the bobbin
case. Loosen rotaing hook bobbin case holder plsition
bracket screw (C) and take down position bracket (A),
then loosen three set screws (D) of rotating hook, At
this point, it took out the rotating hook, it would be
obstructed by feed bar. So that turn the balance wheel
first to raise the feed bar to its highest position, then
take down the rotating hook slowly while to turn it
to step aside of the feed bar, Installing the rotating
hook can be done in reverse sequence.
The projecting flange of the position bracket (A)
should be engaged in the notch (B) of the bobbin
case holder, and maintain a clearance of 0.5~0.7mm
between projecting flange top and the bottom of notch
while installing.
23.Installing feed dog (Fig.28、29)
When feed amount is at the max the front end
of feed dog A is near the front of throat plate slot,
the gauge between the two is 1.5mm this is the
standard position of feed dog.
27
A
C
D
B
0.5-0.7mm
26
A
B
C
D
0.05mm
25
C
D
E
2.5mm
1.2mm
28
A
1.5mm
