Singer 331K4 - Machine Adjustments and Regulation; Bobbin Thread Tension Regulation; Needle Thread Tension Regulation; Presser Foot Pressure Adjustment

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
REGULATION
BOBBIN THREAD TENSION:
For
average
sewing, tension on bobbin
thread
should
be
very
light.
To
regulate
tension on
bobbin
thread,
remove
the
bobbin
case
and
turn screw
in
tension spring,
as
in-
structed
in
Fig.
20
.
.
When
tension on
bobbin
thread
has
been
correctly
adjusted for ordinary stitching,
the required stitch
can usually
be
obtained
thereafter
to suit the work
in
process
by
varying
the tension on needle thread
only.
NEEDLE
THREAD TENSION:
.
To
avoid accumulating excessive tension on
needle
thread,
first
obtain
correct tension on
bobbin
thread,
as
instructed
above.
Regulate needle thread tension
only
when
presser foot
is
down
(since
needle
thread
tension
is
automatically
released
when presser foot
is
raised}.
Tension on
needle
thread
should
be
just enough to
set stitch correctly
in
mate~ial.
Having
lowered
presser foot, turn thumb nut
at
the
front
of
tension discs either
over
toward
right
or
left,
as
required.
See
instructions
in
Fig.
21.
PRESSURE
OF
PRESSER
FOOT
ON
THE
MATERIAL:
The correct presser foot pressure helps
feed
the
work efficiently.
You
can
regulate
the amount
of
pres-
sure
exerted
by
the presser foot on the material
by
means
of
the thumb screw,
as
shown
in
Fil,,
22.
The pressure on the material should
be
as
light
as
possible, while sufficient to insure correct
feeding.
To
increase
the pressure turn the thumb screw
down-
ward.
To
reduce
the pressure turn this screw
upward.
The
pressure
is
correct when the work moves
steadily
and
smoothly without stalling.
9
Fig.
20.
Regulating Bobbin Thread Tension
Fig
..
21.
Regulating Needle Thread Tension
Fig.
22.
Regulating the Pressure on the Material