JUKI DDL-9000C-S Series Engineer's Manual page 71

Adjustment Procedure
3) Adjustment of the thread trimming cam position
1. For checking of the thread trimming cam timing
The purpose of the adjustment of the thread trimming cam is to align
marker line A on pulley cover ❺ with green marker dot B on hand-
wheel ❻.
1. Tilt the sewing machine head. (In the case of H type model, use
white marker dot B´.)
2. Turn handwheel ❻ by hand in the normal direction of rotation until
the thread take-up lever goes up slightly below the upper dead
point. Press cam follower ❶ with fingers to the left (in direction of
arrow E) to fit roller ❷ to in groove C in thread trimming cam ❸.
3. In this state, turn handwheel ❻ in the direction which is opposite to
the normal direction of rotation until handwheel ❻ will go no further.
(If the handwheel is turned further, it reaches the position at which
cam follower ❶ starts moving.)
At this time, marker line A on pulley cover ❺ aligns with green
marker dot B on handwheel ❻.
2. Adjustment of the thread trimming cam timing
1. Tilt the sewing machine head.
2. Loosen the screws No.1 and No. 2 of thread trimming cam setscrew
❼ in the written order.
3. Align marker line A on pulley cover ❺ with green marker dot B
on handwheel ❻. (In the case of H type model, use white marker
dot B´.)
4. Pressing cam follower ❶ to the left (in the direction of arrow E),
engage thread trimming cam ❸ with roller ❷. Then, turn only thread
trimming cam ❸ with fingers in the direction which is opposite to the
normal direction of rotation of feed driving shaft ❹ until it will go no
further without turning feed driving shaft ❹. At this position, tighten
the screws No. 1 and No. 2 of thread trimming cam setscrew ❼
in the written order while pressing thread trimming cam ❸ against
roller ❷.
Results of Improper Adjustment
◦ In the case of using a high-count
filament thread, thread loop forma-
tion may be unstable. If faulty loop
spreading occurs in this state, cor-
rect the thread trimming cam timing
by aligning the marker line on the
pulley cover with the red marker
dot, instead of the green marker
dot, on the handwheel.
◦ The alignment point between
thread trimming cam ❸ and roller
❷ is position (F) from which cam
follower ❶ starts moving. Position
(G) at which you feel that thread
trimming cam ❸ comes in contact
with roller ❷ for the first time during
adjustment is not the correct align-
ment position.
* Be sure to correct the thread trim-
ming cam timing carefully since it
largely affects the loop spreading
timing.
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