Adjustment Of Needle And Looper Timing; Needle Avoiding Looper Timing - SunStar SC 8200J Series User Manual

2) Adjustment of Needle and Looper Timing

When the needle ① descends, and the lowest looper ②'s backward movement is complete, the distance between the
center of the needle and the looper becomes 2.7~2.9mm.
A. Remove the presser foot, the needle plate, and the feed dog.
B. Turn the pulley until the looper ②'s backward movement is complete.
C. Loosen the two adjusting screws ⑦ on the lower shaft pulley ⑥.
D. Turn the pulley toward the user side until the needle ① reaches the lowest position.
E. Tightly fasten the two adjusting screws ⑦.
F. Loosen the adjusting screw ⑧ and move the looper holder ⑨ in the arrow direction until the distance between the
needle center and the tip of the looper becomes 2.7~2.9mm. The tightly fasten the adjusting screw ⑧ again.
G. Check if the looper thread eyes match needle eyes while the loopers are moving back and forth.
H. Assemble the presser foot, the needle plate, and the feed dog.
⑦

3) Needle Avoiding Looper Timing

When the looper moves forward, it moves behind the needle. When the looper moves backward, it moves in front of
the needle. For the forward movement, adjust the distance between the needle and the looper at around 0.05~0.1m.
A. Remove the forward feed arm cover ①.
B. Adjust the timing of the looper heading forward and backward. The adjusting screws on the back which move in
the same direction of the cam moving back and forth should match the screw adjusting hole ③. Then, the
adjusting screws on the back which move in the same direction of the cam moving up/down should match the
looper connecting road adjustment hole ②. For adjustment, loosen the adjusting screw on the front which moves
in the same direction of the cam moving back and forth. Then loosen the adjustment screw on the back to adjust
the cam moving back and forth. When adjustment is completed, tightly fasten the two adjusting screws.
C. Loosen the looper holder screw ④. When the tip of the next looper and the needle center are in a straight line,
move the looper holder ⑤ in the arrow direction to adjust the distance between them at 0.05~0.1mm. Do not
move the looper holder ⑤ in any other direction than the instructed direction. If you did, see "10-2. Adjustment
of Needle and Looper Timing" in page 16 for making adjustment.
D. Assemble the forward feed arm cover ①.
①
⑥
(Looper moving forward) (Looper moving backward)
③
②
①
②
⑤
④
⑨
⑧
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