JUKI MO-6000S series Engineer's Manual page 17

Adjustment Procedures
1) Returning amount of the lower looper
1 Loosen setscrew 2 of lower looper support arm 1 and adjust
lower looper 4 to make adjustment of the returning amount.
(Referential information)
1. Radius K of lower looper 4 will be 66.9 mm when the lower
looper is inserted into lower looper support arm 1 until it
contacts with stopper pin 3 and then is fixed.
2. The rocking angle of the lower looper will be 26˚.
(MO-6 S, R)
The rocking angle of the lower looper will be 32˚.
(MO-69 G, J)
2) Clearance between the lower looper and the needle
MO-6700S Series
1 Loosen setscrew 2 of lower looper support arm 1 to the extent
that it is temporarily tightened. Now, make the adjustment by
moving lower looper support arm 1 back and forth.
MO-6900S, R, G, J Series.
1 Loosen setscrew 2 of lower looper support arm 1 to the extent
that it is temporarily tightened. Then finely adjust the longitudinal
position of the looper using fine adjustment screw 5.
2 Turn fine adjustment screw 5 clockwise to move lower looper
4 away from the needle.
Turn the screw counterclockwise to move lower looper 4 closer
to it.
Results of Improper Adjustment
™ Excessive return of the lower
looper tends to cause stitch
skipping when filament thread is
used.
™ Insufficient return of the lower
looper tends to cause needle
thread stitch skipping when
spun thread is used.
™ Excessive clearance will often
cause needle thread stitch
skipping.
™ Insufficient clearance will cause
needle breakage due to the
contact of the looper with the
needle, or produce scratches on
the blade point of the looper,
l e a d i n g t o n e e d l e t h r e a d
breakage or other troubles.
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