Singer class 251 - Regulating Needle Thread Tension; Regulating Bobbin Thread Tension

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
16
TO
REGULATE
THE
TENSION
ON
THE
NEEDLE
THREAD
lESS
TENSION
Fig.
22.
Regulating
Needle
Thread
Tension
Tension on the needle
thread should be regulated
only
when
the presser foot
is
down.
Tension
on
the
needle
thread
should
be
just
enough
to
set
the
stitch
properly
in
the
material.
Having
lowered
the
presser
foot,
turn
the
thumb
nut
at
the
front
of
the
ten-
sion
discs,
as
instructed
in
Fig.
22.
TO
REGULATE THE TENSION
ON
THE BOBBIN THREAD
When
the
tension
on
the
bobbin
thread
has
been
once
prop-
erly
adjusted,
a
correct
stitch
can
usually
be
obtained
by
varying
the
tension
on
the
needle thread only.
For
average
sew-
ing
the
tension
on
the
bobbin
thread
should
be
very
light.
To
regulate
the
ten-
sion
on
the
bobbin
thread,
remove
the
bobbin
case
and
turn
the
screw
in
the
ten-
sion
spring,
as
in-
structed
in
Fig.
23.
MORE
TENSION
,........_~
__::#
LESS
TENSION
Fig. 23.
Regulating
Bobbin
Thread
Tension
17
TO REGULATE THE LENGTH OF STITCH
BEFORE
DEPRESSING PLUNGER (1)
MAKE
CERTAIN THAT
MACHINE
IS
NOT
RUNNING.
To
change
the
length
of
stitch,
depress
plunger
and
turn
machine
pulley,
over
toward
operator,
slowly,
until
plunger
drops
into
notch
in
the
feed
eccentric,
as
instructed
in
Fig.
24.
Then
turn
machine
pulley,
backward
or
forward,
until
numeral
representing
desired
length
of
stitch is
opposite
the
mark
on
the
front
of
the
arm.
UNTIL
PLU
1.
DEPRESS
_
_/
PLUNGER
....
~
::..,.,
'
'
DRQP.S
INTO N
!I
!l
·l
2. TURN
PULLEY
4.
THEN
TURN
PULLEY
TO
DESIRED
STITCH
LENGTH
Fig.
24.
Regulating
Length
of
Stitch
The
numeral
11
6
11
on
the
stitch
indicator
plate,
shown
above,
indi-
cates
the
longest
possible
stitch;
the
numeral
"30"
indicates
the
shortest
stitch.
Release
the
plunger
when
the
desired
setting
is
obtained.
TO PREVENT OPERATOR
FROM
CHANGING
STITCH LENGTH
The stitch
regulator
plunger
(see Fig. 24)
can
be
removed
to
prevent
an
unauthorized
person
from
changing
stitch
length.
To
remove
the
plunger,
remove
the
retaining
ring
near
the
tip
of
the
plunger,
allowing
the
plunger
to
be
withdrawn.
The
hole
in
the
top
cover
should
then
be
filled
by
inserting
a
plug
screw
140607,
which
can
be
obtained
at
an
additional
charge.