SINGER WHA-1 - Manual (Page 12)

For perfect stitching, the tension
on the upper and under threads
should be equal, and just sufficient“
ly strong to lock both threads in
the center of the work (A)
(A,) Fig. 13
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,
making an imperfect stitch ( B ) .
Fig. U
If the tension of the bobbin thread
is too tight, or if that on the nee­
dle thread is too loose, the bobbin
thread will lie straight along the
under side of the material, making
an imperfect stitch (C).
Regufating the Neecife Tension: Minor
imperfections in the stitch can usually
be corrected by varying the needle
tension only.
To increase the tension, turn the thumb nut
(diagram) clockwise; to lessen the tension,
turn the nut in the opposite direction. The
tension adjust from 0 to 9 in one 360 turn,
with 0 being the lightest tension and 9
being the tightest. All adjusttr.ents should
be made gradually, not abruptly, and the
required tension setting will vary with the
size of thread being used. A little practice
will make instant tensio.n adjustments possible.
All adjustments should be made while the
presser foot is down since an automatic
release does not permit adjustments to be
made when the foot is up. If a perfect
stitch cannot be obtained by adjusting the
needle thread tension, it may be necessary
to adjust the bobbin thread tension as ex­
plained on page 10, Fig. 7. This mach.ine is
correctly adjusted before leaving the factory
and checked and readjusted before the dealer
delivers it to you.
A careful regulation ot the tensions on this
machine will assure you of the finest seams
that mechanical design will produce.
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