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Adjustment Procedures
Results of Improper Adjustment
Adjustment Procedures
Results of Improper Adjustment
1) Loosen screw
1
, and adjust the position of the thread tension
in the state that the thread tension controller is pushed to the
striking face on the machine arm.
1) Loosen setscrew nut
1
, and adjust the longitudinal position of
the pre-tension so that the thread is in parallel to machine arm
as illustrated in Fig. 1.
2) Adjust the orientation of the pre-tension so that the thread
enters the rotary disk straight.
3) Adjust the pressure of the pre-tension so that the rotary disk
rotates smoothly.
™
If the orientation of the pre-
tension is improper, the thread
is bent, and unstable tension and
slip of the rotary disk will occur
resulting thread breakage or
stitch skipping.
1) Pressure of the pre-tension is
excessively low :
Rotary disk does not rotate
smoothly, and defective stitching
or thread breakage will occur.
2) In case of the sewing machine
with thread trimmer, if the
pressure of the pre-tension is
excessively high :
Thread slip at the needle top
after thread trimming or thread
slip at the needle top at the start
of sewing will occur.
