Singer 331Kl User manual

Form ·K6542
(365)
SINGER.
SERVICE MANUAL
*A Trademark of THE SINGER COMPANY
331Kl and 331K4
THE SINCER COMPANY
© 1962 by The Singer Company
Copyright Under International ·Copyright Union
All Rights Reserved under Inter-American Copyright Union
Printed in Great Britain

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
2
CONTENTS
PAGE
DESCRIPTION
.•.•••••••.•.•••••••.••.•.•••••
3
LUBRICATION
AND CLEANING
•••••••••••••••••
4
INFORMATION
FOR
OPERATION
•••••••••••••
4-11
PAGE
ADJUSTMENTS
••••.•••••••••••••••••••••
12-16
PARTS
LIST
.•.•••••••••••••••••••••••••••••
17
INDEX
Bed
Slide (Slide Plate)
••••••••.•••••••••••.•.•
8
Belt Guard
•••••.•••••.•••••••.••••.••••••.•
3
Bobbin and Bobbin
Case
••••••••••.••••••••.
7-9
Bobbin
Winder
•••••••••••••.••••••.•••••••
4, 7
Capacity
of
Machine
•..•.•••••.•.••..•••.•
3,
12
Centralizing Feed Dog
••••.••••••••••••••••••
16
Common
Causes
of
Stitching Troubles
••••••••••••
5
Description
of
Oil
••.•.•.•••..•.••••.••••••••
4
Dimensions
of
Machine
••.••••••.••.•••••••••••
3
Drawing Up Bobbin Thread
•.••••••••••••••••••
8
Feed Dog
••••••••.•••••.•••••••••••••••
1
5,
16
Feed,
Reverse
••••••••.•••••.••••••••••
;
••
3,
10
Feed Timing
•••••••••••••••••.•••••••••••••
15
Graduated Stitch Indicator
••••••••••••••••••••
10
Knee
Lifter
•••••.••••••••.•••••••••••••••••••
3
Length
of
Stitch
••••••..••••..•••••.•.•.•••
3,
10
Light Fixture
••.•.•••••••••••••••••••••••••••
3
Link
Take-up
••••••••••.•••••••••••••••••••
3, 6
Lint, Removal
of
Excess
••.••••.••••••••••..•.••
4
Machine
Dimensions
•••••••••••••••••••••.••••
3
Machine Pulley
•••••.•••••••••••••••••••••
3,
11
Needles
••••••••••.•••.•.••••••••••••.••••••
5
Needle Bar
••••..•••••.••••••.•.•••••
3, 12, 13
Needle Setting
...•..••••••••••••••.•••••••••
5
Needle to Shuttle, Clearance
•••••••.••••••
13,
16
Perfect Stitch
••••••.••••••••.•••...••••••••••
8
Preparation
for
Sewing
..•••.••.••••••.•••.•••
8
Presser Bar
••••.•••••..•••••••
·
•••••.•••••••
12
Presser
Bar Guide Bracket
•••••••.•••••••••••
12
Presser
Foot
•••••••.••••••••.••••••.••
3, 12, 15
Pressure
of
Presser
Foot
•.••••••••••••••••.••
9,
15
Pulley
••••••••••••••••••••••••••••••••••
3,
11
Reverse
Feed
••••••••••••••.•••••••••••••
3,
10
Rotary
Tens
ion
••••••...••••..•••••••••••••
3, 9
Setting Up Machine
•••.•••••.••••••••••••••••
3
Shuttle
•••••••••••••••••••••••••••••••••
13,
14
Shuttle to Needle Clearance
•...•••••.•••••
13,
16
Specifications
•••.••.••••.••.••••..•••••••
3,
12
Speed
•••.••••••••••••••.•••••••••••••.••••
3
Starting to Sew
•••••...•••.•.••••••••••••
8,
11
Spillage, to Avoid
••••.•.•••.•..••••••••••••••
7
Stand
•••••••••••••••••••••••••.••••••••••••
3
Stitch Indicator
•••••••••••••••••••••••••.••
10
Stitch Length
•••••••••••••••••••••••••••••••
10
Stitch Type
•••••••••••••••••••••••••••••••••
3
Stitching Troubles,
Causes
of
••.••••••••••••••••
5
Stop Motion
••.•..•••••••••.••.••••••••••••
11
Table
•.••.••.•.••••••••••••••••••••••.•••••
3
Tacking
•••••.••••.••••••••••••••••••••••••
10
Take-up Lever
•••••••••••••••••••••.••••••
3, 6
Take-up Lever Guard
..••••.•••.••••••••••••••
3
Tension,
Check Spring
•.•••...•.•••••••••••••
1
4
Tension,
Threads
••.••••••••.•.•••••••••••••
8, 9
Thread
.•••••••••••••••••••.•.••••••••••••••
5
Threading, Bobbin Case
•••••••••••••••••••••••
7
Threading,
Upper
(Needle)
•••••••••••.••.•••••
6
Throat Plate
••••••••••••••••.••••••••••••
3,
16
Treated Material, Speed when Sewing
•••••••••••
3
Treadling Procedure
•••••••••••••.••••••••••
11
Turning a Corner
•.•••••••••.•••••••••••••••••
8
Twist
of
Thread
••••••.••.••••••••••••••••••••
5
Unwinder
••••••••••••••••.••••••••••••••••
3, 6
Upper Threading
••••••••.••••••••••••••.••••
6
Winder
(Bobbin)
•••••••••••••••••••••••••••
4, 7

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
DESCRIPTION
Machines
331K1
and
331K4 produce
top
quality,
single-needle, straight-line lock stitching
in
suits, shirts,
skirts
and
other
clothing.
MACHINE 331 K1:
Stitch Type #301.
Central bobbin.
Short
beak,
oscillating shuttle on horizontal axis.
Link
take-up.
Thread
take-up
lever
guard.
Drop
feed.
Hinged presser foot 161066.
Feed
dog
149603.
Throat
plate
26606.
Length
of
stitch controlled
by
regulator thumb screw
on front
of
machine arm.
Maximum stitch
length-5-1
/3 to the
inch.
Front, intermediate
and
rear
plain bearings.
Clamp
type
needle
bar.
Tapped
hole
and
seat
in
rear
of
arm provided for
mounting light fixture independently
of
presser
bar
lifting lever hinge screw.
Needle
bar
stroke
is
1.472 inches.
Clearance
under presser foot
is
5/16
inch.
Machine dimensions: Bed length
18-3/4
inches,
width
7
inches.
Belt guar,d 174112
available
on
order.
Knee lifter 139625 regularly supplied.
3
MACHINE 331K4:
Similar to
Machine
331
K1, with the following
exceptions:
Spring-biased, quick reversible
feed
mechanism
permits
operator
to
feed
work
backward
or
forward
at
will.
Solid presser foot 12144.
Feed
dog
149304. Throat
plate
12414.
INSTALLATION
Before placing the machine
in
its
cut-out on
table,
see
that
the four cushioning
pads
are
at
the four cor-
ners
of
the cut-out. Place the machine on these
pads.
SPEED
The maximum
speed
for these machines
is
2200
stitches
per
minute, according to the material sewn
and
the
type
of
work being done.
It
is
advisable
to
operate
these machines
at
a more
moderate
speed
the first few
days,
after
which they
can
be
operated
at
maximum
speed.
Reduce speed
of
machine when sewing closely
woven fabrics
or
treated
materials.
MACHINE
PULLEY
Machine pulley 139724 (solid discs,
balanced)
has
an
outside
diameter
of
belt
groove
of
2.90
inches
for
3/8
inch
V-belt. Effective
diameter
for
5/16
inch
round
leather
belt
is
2-5
/ 16 inches.
When
in
operation, the
top
of
the machine pulley
must
always
turn
over
toward
the
operator.

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
LUBRICATION AND CLEANING
Use
SINGER* OIL, "TYPE B"
or
"TYPE
D".
Use
"TYPE
D"
OIL
when
an
oil
is
desired
which
will
produce
minimum stain
on
fabrics.
A machine in
continuous
use
should
be
oiled
fre-
quently.
Frequency
is
dependent
upon
the
speed
at
which the machine
is
operated
and
the
type
of
work
being
done.
Basically the machine needs
oiling
at
least
twice
each
working
day.
Before
starting
the machine,
at
the
beginning
of
the
day
and
again
after
the
midday
recess,
apply
a
few
drops
of
oil
at
each
of
the
oiling
points on the machine.
Arrows
indicate
oiling
points in
Figs. 2
through
5.
Never
attempt
to
oil
shuttle
race
(See
Fig.
S)through
holes in
throat
plate.
REMOVE
SCREW
AND
REMOVE
FACE
PLATE
4
BOBBIN WINDER LUBRICATION
Oil
bobbin
winder
occasionally
by
applying
a
few
drops
of
oil
to
oil
wick
in
bobbin
winder
frame,
as
instructed in
Fig.
11,
page
7.
CLEANING
Clean
out
all
lint
and
abrasive
matter
from
around
the shuttle
and
between
the
feed
rows on the
under-
side
of
the
throat
plate.
Close
all
covers
after
oiling
and
cleaning.
Wipe
off
excess
oil
from
surfaces
of
machine
that
may
come in
contact
with
material.
• •
Fig.
2.
Oiling
Points-Front
View
Fig. 4. Oiling beneath Machine
Bed
•
#S·~li.
(//r(F_,""·
:.".c:..=,.~'lff!!:,'t:'::::~;":·~::·:::~"=:::.~:.::;;,:;::::':"
\
'
'
Fig.
3.
Oiling
Points-Rear
View
Fig.
5.
Oiling
Points
behind
Face
Plate
and
in
Shuttle
Race

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
THREAD
On Machines of Class 331K, use only left twist
thread in the needle. Either right or left twist thread
can be used in the bobbin.
To determine the thread twist, hold the thread as
shown in Fig. 6. Then twirl the thread over toward you.
If the strands of the thread wind tighter, the thread is
left twist, if the strands unwind or separate, the thread
is right twist. Rough or uneven thread, or thread which
passes with difficulty through the eye of the needle,
will interfere with the successful use of the machine.
NEEDLES
The needle you select will have a very direct effect
on the quality, strength
and appearance of the stitch
produced
by the machine.
In selecting a needle size ... the eye must be large
enough to allow the thread you are using to pass
through freely without binding or chafing. A simple
test
is to thread a short length of thread through the
eye of the needle selected; hold the thread taut in a
vertical position.and twirl the
needle about the thread.
If the size is correct, the needle should slip down the
thread easily.
Needles for this machine
are of Catalog #2055
(16 x 87)
in Sizes 8 to 14, 16 to 19 and 21 to 25.
Orders for needles must specify the Quantity
required, the Size number, also the Catalog number.
For example:
"100 Size 16, Catalog #2055
(16 x 87) Needles"
For best results always use SINGER needles.
TO SET THE NEEDLE
Turn the machine pulley over toward you until the
needle bar moves to its highest point.
After loosening
needle clamping screw, remove old
needle and insert new needle UP into needle bar AS
FAR AS IT WILL GO, as instructed in Fig. 7.
The single continuous groove of the needle MUST
face away from the shuttle point (toward the left end
of the machine, as shown in Fig. 7) with eye of needle
directly in line with arm of machine.
Securely tighten
needle clamping screw.
5
HOLD THIS END
Fig. 6. How to Determine the Twist
VE TO
HEST POINT
T NEEDLE UP
AR AS POSSIBLE
TIGHTEN SCREW
Fig. 7. Setting the Needle
COMMON CAUSES OF STITCHING TROUBLES
Check needles often to make sure these defects are
not present ...
• Wrong needle for thread and material in use.
• Bent needle, clogged needle eye, or dirty
needle grooves may cause skipped stitches.
• Hook or bur~ on needle point may cause picking
or fraying of the material.
• Incorrect setting of needle.