SINGER 15-91 - Manual (Page 22)

Tensions
For ordinary stitching, the needle and bobbin
threads should be locked in the center of the thick­
ness of the material, thus:
20
F ig .
15.
P erfect S titch
If the tension on the needle thread is too tight, or
if that on the bobbin thread is too loose, the needle
thread will lie straight along the upper surface of
the material, thus:
¿■//j/d
F ig . 16. T ight N eedle T hread T ension
If the tension on the bobbin thread is too tight,
or if that on the needle thread is too loose, the bobbin
thread will lie straight along the under side of the
material, thus:
EllJIi
F ig . 17. L oose N eedle T hre .^ d T ension
To Regulate the Needle Thread Tension
The tension on the needle thread can be regulated
only when the presser foot is down.
The numbered
A Q ^ ^ A dial (C, Fig. 18) is
marked with num­
bers ranging from 0
to 9, which indicate
different degrees of
tension which can be
produced. The num­
bers do not denote
a particular size of
thread.
.. C E13356 h J By n o t i n g t h e
F ig .
18.
N eedle T hread T ension
number which is op­