Adjusting The Thread Trimmer; For Checking Of The Thread Trimming Cam Timing; Adjustment Of The Thread Trimming Cam Timing - JUKI DDL-8000AS Instruction Manual

5-3. Adjusting the thread trimmer

WARNING :
Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the
sewing machine.
❸
❶
E
❼
❷
Turn thread trimming cam ❸ in the direction of
arrow until the outer periphery of thread trimming
cam groove C comes in contact with roller ❷ and
stops. At this position, fix thread trimming cam
setscrew ❼ .
Correct (F)
❷
C
❷
Illustration as observed from D (right side face)
❻ B
A
C
❺
❹
D
Wrong (G)
❷
C
❹
C
❸
– 60 –
5-3-1. For checking of the thread trimming
cam timing
The purpose of the adjustment of the thread trim-
ming is to bring marker line A on electrical box
cover ❺ to the portion between the colorless marker
dots B and C on handwheel ❻ .
1) Tilt the sewing machine head.
2) Turn handwheel ❻ by hand in the normal direc-
tion 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 direc-
tion 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, adjust so that the marker line A on
electrical box cover ❺ is brought to the portion
between the colorless marker dots B and C on
handwheel ❻ .
5-3-2. Adjustment of the thread trimming
cam timing
1) Tilt the sewing machine head.
2) Loosen the screws No.1 and No. 2 of thread trim-
ming cam setscrew ❼ in the written order.
3) Align marker line A on electrical box cover ❺
with the colorless marker dot B on handwheel ❻ .
4) Pressing cam follower ❶ to the left (in the direc-
tion 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 op-
posite 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 trim-
ming cam setscrew ❼ in the written order while
pressing thread trimming cam ❸ against roller ❷ .
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
alignment position.
* Be sure to correct the thread trimming
cam timing carefully since it largely
affects the loop spreading timing.