SINGER 15-91 - Manual (Page 23)

posite the center line (Q) on the indicator (G)
when set for a satisfactory tension on the work
being stitched, the number can be readily reverted
to when a change is made in the tension or size of
thread.
To I ncrease the Tension, turn the thumb nut
(A) over toward you (over to the right) until the
desired number on the numbered dial (C) is oppo­
site the center line (Q), the higher numbers denoting
increased tension.
To Decrease the Tension, turn the thumb nut
(A) over away from you (over to the left), the lower
numbers indicating less tension.
The tension indicator (G) is marked with the signs
-f- and —, which indicate the direction in which to
turn the thumb nut (A) for more or less tension.
CAUTION —It is important for the tension thumb
nut (A, Fig. 18) to have a firm fit on tension stud
(N, Fig. 19), to keep the numbered dial (C) in the
position set for the required tension. To remedy a
loose fit of the nut, remove parts A, C, D, F and G,
Fig. 20, and slightly spread the stud, then re-assemble
the parts as instructed on pages 22 to 24 inclusive.
To Regulate the Bobbin Thread Tension
The tension on the bobbin thread is regulated by
the screw (O, Fig. 8) in the bobbin case tension
spring. To increase the tension, turn this screw over
to the right. To decrease the tension, turn the screw
over to the left.
When the tension on the bobbin thread has once
been properly adjusted, it is seldom necessary to
change it, as a correct stitch can usually be obtained
by varying the tension on the needle thread.
To Disassemble the Needle Thread Tension
NOTE: The needle thread tension. Figs. 18
to 20 inclusive, is correctly adjusted at the fac­
tory to produce the complete range of tensions
with one revolution of the thumb nut (A).
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