Singer 20U31 User manual

Service Manual
SINGER*
20u31/33/35
MACHINES
THE SINGER COMPANY

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
CONTENTS
Description
Sewing
Defects
and
Adjustments
To·Set
Needle
Bar
at
Correct
Height
Relation
Between
Needle
and
Rotating
Hook
To
Adjust
Sidewise
Movement
of
Needle
while
in
the
Material
(Zigzag
Stitching)
To
Adjust
Needle
Location
in
Relation
to
Needle
Hole
in
Throat
Plate
.
To
Obtain
Uniform
Straight
Stitch
To
Set
Feed
Dog
at
Correct
Height
To
Centralize
Feed
Dog
in
Throat
Plate
Slots
To
Set
Presser
Bar
at
Correct
Height
Timing
the
Feed
Positioning
the
Feed
and
Feed
Lifting
Eccentric,
Feed
Forked
Connection,
Feed Rock
Shaft
Crank,
Feed
Lifting
Rock
Shaft
Crank
Connecting
Rod
and
Feed
Lifting
Rock
Shaft
Crank
Adjustment
of
Tension
.
Adjustment
of
Backlash
,.. A
Trod~marlr
of
THE SINGER
COMPANY
Copyri9ht
O
1980
THE
SINGER
COMPANY
All
Rights
Aes.rn,ed
Throughout
the
World
Page
1
2
3
4
5
6
14
14
15
17
18
20
20
22

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
DESCRIPTION
Model 20U artisan machine produces top quality straight and zigzag
stitches in fabrics as fine as ladies' lingerie or as heavy as overcoating.
GENERAL FEATURES
* Rotating hook
*
Link take-up
* Stitch length controlled by feed regulating dial
* Needle position selector places stitching in left, center or right needle
positions
* Spring biased stitch width selector which can also be set at desired stitch
width
SPECIFICATIONS
* Maximum stitch width
* Maximum stitch length
* Needle bar stroke
* Height of presser foot from top surface
of throat plate
* Thread take-up lever stroke
* Needle bar height (Distance from throat
plate seat to needle stop in needle bar
at its lowest position)
* Speed - up to 5 mm stitch width
over 5 mm and up to maximum
stitch width
* Diameter of machine pulley (for motor
drive)
- 1 -
9mm
5 s. p. i. (5 sti tches/25 .4 nnn)
34.8 mm
6.35 mm
63.5 mm
25.07 mm
2,500 r.p.m.
2,000 r.p.m.
75 mm (3 in.)

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
SEWING
DEFECTS
AND
ADJUSHIENTS
ects
Need
le
Thread
Skip
Looping, Improper Uneven
Breakage Brec1kage
Stitching
Stagger
&
Feeding
Puckering
Zigzag
Noise
Place
of
Adjustmen~
Hitch
Stitch
Stitches
1. Thread -
X
X
X
-X
2.
Need
1e
X X X
X -X
X
3. Needle Bar X X
X ----X
4.
Rotating
Hook
-X X
----X
s.
Bobbin Case -
X
-X -X
6. Needle
Thread
Tension
-X -X X X
X
N
7. Thread Take-up Lever -
X
---
--X
8.
Presser
Foot X
X X
-
X
X
9.
Feed ----
X
X -X
10,
Throat
Plate
X
X --X
11. St i t ch
\~
i
cl
th X
12. Needle
Position
X
13,
Material
X
--- - X
X
14. Gear
-
------
X

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
TO
SET
NEEDLE
BAR
AT
CORRECT
HEIGlIT
OlECK:
1.
Remove
face
plate.
2.
Set
needle
position
selector
on
"center"
and
stitch
width
regulator
for
straight
stitching.
3.
Turn
machine
pulley
over
toward
you
until
needle
descends
to
its
lowest
position.
4.
Check
whether
upper
timing
mark
on
needle
bar
is
level
with
underside
of
needle
bar
timing
indicator
plate.
CAUTION:
The
needle
bar
timing
indicator
plate
has
been
correctly
positioned
at
the
factory
and
it
SHOULD
NOT
BE
DISTURBED.
ADJUSTMENT
:
If
needle
bar
is
not
set
at
correct
height,
then
adjustment
should
be
made
as
instructed
belm,.
1.
With
machine
set
for
straight
stitching
at
center
needle
pos1t1on,
turn
machine
pulley
until
ntedle
bar
is
at
its
lowest
position.
2.
Loosen
needle
bar
set
screw
so
that
only
the
needle
bar
will
move
up
and
down
freely.
3.
Move
needle
bar
up
or
down
as
required,
and
align
its
upper
t1m1ng mark
with
underside
of
needle
bar
timing
indicator
plate.
Then
securely
tighten
needle
bar
set
screw.
4.
Replace
face
plate.
Needle
Bar
Connecting
Stud
Fig.
1
- 3 -
Needle
Bar
Timing
Indicator
Plate
Needle
Bar
Set
Screw
Needle
BaT

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
RELATION
BETWEEN
NEEDLE
.AND
ROTATING
HOOK
A.
TO
TIME
TIIE
ROTATING
HOOK
CHECK:
1.
Set
needle
position
selector
on
"center"
and
stitch
width
regulator
for
straight
stitching.
2.
Turn
machine
pulley
over
toward
you
until
needle
rises
2.54
ma
from
its
lowest
position
and
the
lower
timing
mark
is
level
with
the
underside
of
needle
bar
timing
indicator
plate.
When
the
needle
bar
is
in
the
above
position,
the
point
of
rotating
hook
should
be
at
the
center
of
the
needle
as
shown
in
Fig.
2.
ADJUSTMEN1:
If
the
t1m1ng
of
rotating
hook
in
relation
to
the
needle
requires
correc-
tion,
make
adjustments
as
instructed
below.
1.
Set
machine
for
straight
stitching
at
center
needle
position.
2.
Remove
rotating
hook
shaft
bevel
gear
cover.
3.
Loosen
two
rotating
hook
set
screws
and
adjust
rotating
hook
as
required.
Retighten
set
screws.
'
Needle
'I
Hook
Point
;I
0.5
2.42
2.57
:
I:
I
4.25
:
I.
I
I
I '
I
2.54
r
'
' ' I
\j/
1.21
'I'
)'.
\I/
'j,c
'
Left
Needle
Position
Center
Needle
Position
Right
Needle
Position
Fig.
2
B.
~HECK
TIMING
OF
ROTATING
HOOK
AND
NEEDLE
(AT
LEFT,
CENTER
AND
RIGITT
NEEDLE
POSITIONS)
1.
Turn
machine
pulley
over
toward
you and make
sure
the
needle
is
free
from
any
interference
when
it
is
swung from minimum
to
maximum
bight
at
left,
center
and
right
needle
positions.
- 4 -

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
2. Set stitch width regulator for straight stitching and check (visually)
whether the relationship between needle and rotating hook is as shown in
Fig. 2 (at center and left needle positions) just when needle Tises from
its lowest position.
3. Be sure the clearance between needle and hook
point is O - 0.05 mm (Fig. 3) regardless of left,
center, or right needle pasitions. Excessive
clearance may result in skip stitching.
Adjustment should be made in the same way as
explained in paragraph A, "TO TIME THE ROTATING
HOOK".
TO ADJUST SIDEWISE MOVEMENT OF NEEDLE
WHILE IN TI-!E MATERIAL (ZIGZAG STITCHING)
0 - 0.05
Hook Point
Needle
Fig. 3
When zigzag stitching, the needle must not move sidewise while its point
is still in the material, or in the needle hole in throat plate. The-needle
should make its upward or downward movement only after completing its swing
to the left or right as shown in Fig. 4.
v v
l'
/ ' I '
✓'
/
";
'
.,
.,
I ' ' /
I ' ,
~
~
'
-- '
/
' /
'
✓
' ,
I
\.
A I
\
,.
' I
I + " ~
,t
It-
I
I \
/ \
I '
A
, '
..
! '
I '
...
.,
• I
I '\ \ I
~~
Correct Wrong Wrong
Fig. 4
Fig. 5-a
Fig. 5-b
If the needle continues its swing even as it enters the needle hole in
throat plate, or when it begins to rise as shown in Fig. 5-a and 5-b, such
condition should be corrected by making the following adjustments.
·- 5 -

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
ADJUSTMENT:
1.
Turn
machine
pulley
over
toward
you
until
needle
bar
is
at
its
lowest
position.
2.
Remove
screws
and
lift
off
arm
top
cover.
Loosen
the
zigzag
triangular
cam
shaft
collar
set
screw
and
slide
collar
toward
front
of
machine.
Check
whether
the
two
zigzag
triangular
cam
set
screws
(with
center
line
aligned)
are
located
parallel
to
the
bearing
face
of
the
zigzag
stitch
Tegulator
fork.
3.
If
the
triangular
cam
set
screws
are
not
located
parallel
to
the
bearing
face
of
the
stitch
regulator
fork,
loosen
arm
shaft
(horizontal)
worm
gear
set
screws
and
turn
arm
shaft
worm
gear
as
required
until
the
triangular
cam
set
screws
are
in
either
one
of
the
two
positions
shown
in
Fig.
6.
Then
securely
tighten
arm
shaft
worm
gear
set
screw.
4.
Check
rith
a
dial
gage
(Fig.
11)
to
see
whether
the
needle
is
still
making
sidewise
movement
while
in
the
fabric
and
below
throat
plate,
and
if
necessary,
readjust
as
instructed
above.
CHECK:
Zigzag
Triangular
Cam
Set
Screw
To
Be
Par
all
el
---\✓
---
Fig.
6
TO
ADJUST
NEEDLE
LOCATION
IN
RELATION
TO
NEEDLE
HOLE
IN
THROAT
PLATE
To
Be
Parallel
--'{
---
1.
Fit
needle
to
needle
clamp.
(Make
sure
the
needle
is
not
bent.)
2.
Set
needle
position
selector
on
"center"
and
stitch
width
regulator
for
straight
stitching.
- 6 -

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
4.
Turn
iaachine
pulley
slowly
until
needle
descends
into
the.needle
hole
in
throat
plate
(for
zigzag
stitching)
and
check
whether
or
not
the
needle
is
properly
located
in
the
center
of
the
needle
hole
(Fig.
7).
s. Change
throat
plate
to
straight
stitching
throat
plate,
lower
needle
hole
and
check
whether
it
is
properly
centered
or
not.
plate
to
zigzag
stitching
throat
plate.
needle
into
Change
throat
6.
Move
stitch
width
regulator
to
maximum
stitch
width
and
while
holding
regu-
lator
in
this
position,
turn
machine
pulley
and
check
left
and
right
needle
locations
in
relation
to
the
center
of
needle
hole
in
throat
plate.
Also
check
left
and
right
needle
locations
in
relation
Lo
the
needle
hole
with
need.le
position
set
at
left
and
right
of
center.
-
Center
~
l~
Fig.
7
Fig.
8
Fig.
9
ADJUSTMENT:
If
the
needle
location
is
offset
to
the
left
or
to
the
right
of
center
and
the
clearance
between
needle
and
edge
of
hole
at
left
and
right
is
not
equal,
or
if
needle
continues
to
swing
even
when machine
is
set
for
straight
stitching,
and
if
for
any
reason
it
is
necessary
to
replace
and
adjust
related
parts,
then
adjust
as
instructed
below.
A.
TO
ELIMINATE SIDEWISE
MOVEMENT
OF
NEEDLE
WHEN
MAO-HNE
IS
SET
FOR
STRAIGITT
STITOiING
1.
Fit
needle
plug
to
needle
clamp.
(Make
needle
plug
by
grinding
down
the
point
of
a
needle.)
Fig.
10
- 7 -
rr:2
i~=t
20
mm

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
2.
Loosen and Temove arm
side
cover.screws
..and.rernove
side
cover.
Remove
arm
top
cover
screws
and
lift
off
top
cayer.
3.
Set
needle
position
selector
on
"center"
and
stitch
width
regulator
for
straight
stitching.
4.
Turn
machine
pulley
over
toward
you and check
existence
of
sidewise
movement
of
needle.
(Fig.
11)
5.
If
there
is
a
sidewise
movement
in
the
needle,
loosen
bight
amplitude
stop
plate
(left)
set
screw
and move
left
bight
amplitude
stop
plate
(marked with
asterisk)
to
the
left
or
right
as
required,
until
the
sidewise
movement
is
eliminated.
(Fig.
12)
Check,
using
a
dial
gage
lFig.
11),
and
make
sure
the
sidewise
movement
(if
any)
is
held
to
less
than
0.05
and
securely
tighten
set
screw.
Needle
Bar Frame
Fig.
11
- 8 -

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
BIGHT
AMPLITUDE
REGULATOR
AND
NEEDLE
POSITION
SELECTOR
MEQiANISHS
VIEWED
FROM
BACK
OF
MACHINE
Fig.
12
- 9 -

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
Ref.
No.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
*
.Description
Bight
and
Needle
Position
Lever
Arm
Regulating
Screw
Nut
(left
and
right)
Bight
Amplitude
Regulating
Plate
(right)
Thumb
Screw
Bight
Amplitude
Regulating
Plate
(right)
Bight
Amplitude
Stop
Plate
(left
and
right)
·screw
Bight
Amplitude
Stop
Plate
(left
and
right)
Washer
Bight
Amplitude
Regulating
Plate
Holder
Bight
Amplitude
Stop
Plate
(right)
Bight
Amplitude
Regulating
Plate
Holder
Screw
Bight
Amplitude
Slide
Block Crank
Bight
and
Needle
Position
Lever
Arm
Regulating
Screw
Bight
and
Needle
Position
Lever
Arm
Regulating
Screw
Bight
Amplitude
Slide
Block Crank
Set
Sere....,
Bight
Amplitude
Slide
Block Crank
Shaft
Bight
and
Needle
Position
Block
Bight
and
Needle
Position
Lever
Thumb
Stud
Nut
Bight
and
Needle
Position
Block
Set
Screw
Bight
and
Needle
Position
Lever
Bight
and
Needle
Position
Lever
Set
Screw
Bight
and
Needle
Position
Lever
Arm
Bight
Amplitude
Slide
Block Crank
Link
Bight
Amplitude
Slide
Block Guide
Stud
Set
Screw
Bight
Amplitude
Slide
Block
Bight
Amplitude
Slide
Block
Cap
Screw
Zigzag
Stitch
Regulator
Fork
Bight
Amplitude
Slide
Block Guide
Bight
Amplitude
Stop
Plate
(left)
Bight
Amplitude
Slide
Block Crank
Spring
Bight
Amplitude
Regulating
Plate
(left)
Bight
Amplitude
Regulating
Plate
Spring
Bight
Amplitude
Regulating
Plate
(
left)
Thumb
Screw
-
10
-
(right)
(left)
1
!
i
,.

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
6_ Lower
needle
into
needle
hole
in
throat
plate
and
check
whether
the
needle
is
properly
centered
in·the
needle
hole.
1.
If
needle
is
not
properly
centered
in
the
needle
hole,
check
whether
the
notch
on
the
hexagon
head
of
the
zigzag
stitch
regulator
fork
eccentric
connection
pin
(Fig.
15)
is
located
at
top,
then
loosen
bight
and
needle
position
block
set
screw
and
adjust
bight
and
needle
position
block
to
the
left
or
right
as
required.
Securely
tighten
the
set
screw.
8.
Turn
machine
pulley
and
check
existence
of
sidewise
movement
of
needle.
If
it
is
found
necessary
to
make
readjustment,
it
should
be
made
as
instructed
in
item
5,
page
8.
B.
ADJUSTMENT
TO
OBTAIN
MAXIMUM
ZIGZAG
STITCH
WIDTH
(9
mm)
1.
Set
needle
position
selector
on
"center"
needle
position
and
stitch
width
regulator
for
maximum
stitch
width.
2.
Place
a
light
card
under
presser
foot,
turn
machine
pulley
and
make
light
needle
punctures
in
the
card
and
check
width
of
zigzag
stitch.
3.
If
maximum
stitch
width
of
9
mm
can
not
be
obtained
with
machine
set
as
instructed
above,
loosen
bight
amplitude
stop
plate
(right)
screw
and move
bight
amplitude
stop
plate
(right)
to
the
left
or
right
as
required.
Then
securely
tighten
set
screw.
Fig.
13
' ,
---------
--
C.
SETTING
THE
CENTER
NEEDLE
POSITION
1.
Set
needle
position
selector
on
11
center
11
needle
position
and
stitch
width
regulator
for
straight
stitching.
Place
a
light
card
under
presser
foot,
turn
machine
pulley
and make a
needle
puncture
on
the
card.
Then
set
stitch
width
regulator
for
maximum
stitch
width,
make
needle
punctures
on
the
card
in
the
same way
as
above
and
check
whether
the
left
and
right
needle
punctures
are
equally
distanced
from
the
center.
Fig.
14
'
'
2.
If
left
and
right
needle
locations
are
not
equidistant
from
the
center,
loosen
bight
and
needle
position
block
set
screw
and move
bight
and
needle
-11 -

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
position
block
to
the
left
or
right
as
required.
Securely
tighten
set
screw
when
correct
needle
location
is
ohtainec.
If
correct
needle
locations
cannot
be
obtained
by
making
the
above
adjust-
ment,
th.en
the
bight
and
needle
position.lever
and
bight
and
needle
Position
lever
arm
should
be
adjusted
as
follows.
a.
Loosen
bight
amplitude
slide
block
crank
set
screw
and
remove
bight
amplitude
slide
block
crank
shaft
in
order
to
move
bight
amplitude
slide
block
crank
out
of
the
way
to
make
adjustments.
b;
Loosen
the
two
bight
and
needle
position
lever
set
screws
and
adjust
bight
and
needle
position
lever
in
relation
to
bight
and
needle
position
lever
arm.
After
making
the
adjustment,
securely
tighten
the
two
set
screws.
c.
Replace
bight
amplitude
slide
block
crank
shaft.
set
bight
amplitude
slide
block
crank
in
proper
position
and
securely
tighten
the
slide
block
crank
set
screw.
If
needle
position
selector
is
not
in
alignment
with
the
marking
on
front
of
the
arm
standard,
readjust
bight
and
needle
position
block
in
the
same
way
as
instructed
above.
D.
SETTING
THE
LEFT
NEEDLE
POSITIO~
1.
Set
needle
position
selector
on
"left"
needle
position
and
turn
machine
pulley
to
bring
needle
to
its
lowest
position.
2.
Move
stitch
width
regulator
to
maximum
bight
a few
times
and
check
to
see
that
sidewise
movement
of
needle
is
within
1 - 2
mm.
If
needle
makes a
full
9
mm
swing,
turn
machine
pulley
over
toward
you one
complete
turn,
that
is,
raise
needle
to
the
top
once
and
bring
it
down
to
its
lowest
position
again,
then
check
sidewise
movement
of
needl~
as
instructed
above.
3.
If
needle
makes a
slight
sidewise
movement when
stitch
width
regulator
is
moved
to
its
maximum
bight,
this
should
be
corrected
as
follows.
Loosen
bight
and
needle
position
lever
arm
regulating
screw
nut
(right)
and
turn
bight
and
needle
position
lever
arm
regulating
screw
(right)
clockwise
or
counterclockwise,
as
required,
and
temporarily
tighten
set
screw.
Make
certain
the
sidewise
movement
of
needle
is
less
than
0.1
mm,
then
securely
tighten
set
screw.
E.
SETTING
THE
RIGHT
NEEDLE
POSITION
l.
Set
stitch
width
regulator
for
straight
stitching
and
needle
position
selector
on
"left"
needle
position.
Place
a
light
card
under
presser
foot,
turn
machine
pulley
and
make a
needle
puncture
on
the
card
in
the
same
way
as
above
and
measure
distance
between
left
and
right
needle
locations.
-
12
-

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
2.
If
there
is
not
a
9.0
mm
distance
between
the
left
and
right
needle
locations,
loosen
bight
and
needle
position
lever
arm
regulating
screw
nut
(left)
and
turn
bight
and
needle
position
lever
arm
Tegulating
screw
(left)
Clockwise
or
cotmterclockwise,
as
required,
and
retighten
set
screw.
F.
FINAL
ADJUSTMENT
OF
NEEDLE
LOCATION
1.
Check
needle
location
in
relation
to
the
needle
hole
in
throat
plate
at
maximum
bight
in
left>
center
and
right
needle
positions.
2.
Remove
general
purpose
throat
plate
and
replace
with
throat
plate
for
straight
stitching.
Set
needle
position
selector
on
"center"
needle
position
and
stitch
width
regulator
for
straight
stitching.
Then
lower
needle
into
hole
in
throat
plate
and
check
needle
location.
3.
If
the
needle
location
in
relation
to
the
needle
hole
in
throat
plate
need
to
be
adjusted,
loosen
zigzag
stitch
regulator
fork
eccentric
connection
pin
set
screw
(Fig.
15) and
turn
zigzag
stitch
regulator
fork
eccentric
connection
pin,
as
required,
to
obtain
correct
needle
location.
4.
Make
certain
that
needle
is
correctly
located,
and
securely
tighten
set
screw.
Then
change
straight
stitch
throat
plate
to
general
purpose
throat
plate.
--
Zigzag
Stitch
Regulator
Fork
Zigzag
Stitch
Regu-
lator
Fork
Eccentric
Connection
Pin
Socket
Hea<l
Wrench
Fig.
15
-
13
-
Needle
Bar
Frame
Zigzag
Stitch
Regulator
Fork
Zigzag
Stitch
Regu-
lator
Fork
Eccentric
Connection
Pin
Zigzag
Stitch
Regu-
lator
Fork
Eccentric
Connection
Set
Screw
Socket
Head
Wrench
Enlarged
View

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
TO
OBTAIN
UNIFORM-STRAIGHT
SI'ITCH
The
position
of
bight
amplitude
stop
plate
(left)
requires
adjustment
if
the
machine
produces
uniform
straight
stitches
when
stitch
width-regulator
is
still
located
slightly
in
front
of
the
zero
position
(just
before
regulator
is
located
completely
on
zero
position)
or
when
the
machine
produces
a
staggered
or
uneven
stitches
even
when
the
stitch
width
regulator
is
set
at
zero
position
for
straight
stitching.
To
aake
the
above
adjustment~
follow
the
instruction
given
on
page
7
under
"TO
ELIMINATE
SIDEWISE
MOVEMENT
OF
NEEDLE
WHEN
MAGiINE
IS
SET
FOR
STRAIGHT
STITCHING"
TO
SET FEED
DOG
AT
CORRECT
HEIGITT
When
feed
dog
is
at
its
highest
position,
the
teeth
should
project
1.02
-
1.09
mm
above
the
top
surface
of
the
throat
plate.
If
feed
<log
is
set
too
low,
proper
stitch
length
can
not
be
obtained
due
to
improper
feeding
of
the
material,
and
when
set
too
high,
it
may
interfere
with
the
underside
of
the
throat
plate.
These
conditions
should
be
corrected
by making
the
following
adjustments.
ADJUSTMEIIT:
1.
Raise
presser
foot
and
turn
machine
pulley
over
toward
you
to
bring
feed
dog
to
its
highest
position
above
throat
plate.
2.
Loosen
feed
lifting
rock
shaft
crank
clamping
screw
and
-turn
£eed
lifting
rock
shaft
toward
you
or
away from you,
as
required.
Then
securely
tighten
clamping
screw
when
correct
height
is
obtained.
Fig.
16
-
14
-
Feed
Lifting
Rock
Shaft
Crank Clamping Screw
Machine
Bed
Feed
Lifting
Rock
Shaft
Crank

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
TO CENTRALIZE FEED DOG IN THROAT PLATE SLOTS
Feed dog should not contact edges of throat plate slots during its movement
but should be located centrally in relation to the front. rear and sides of
throat plate slots.
Before making any unnecessary adjustments to the feed dog. check that it
lies parallel to the throat plate slots.
LENGTI-fWISE SETTING:
1. Set machine for maximum stitch length.
2. Loosen feed rock shaft crank clamping screw (Fig. 17) and move feed bar and
feed rock sha£t, as required.
3. Securely tighten clamping screw.
t
t Feed
Forked Connection
Feed Bar
Feed Rock Shaft
Feed Rock Shaft Crank
Fig. 17
Feed dog should be set so that its movement
is equidistant from front and rear edges of throat
plate slots, or have at least 1 mm clearance as
shown in Fig. 18 when it is located nearest to the
front of machine.
- lS -
Feed Rock Shaft Crank
Clamping Screw
Fig. 18

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
SIDEWISE
SETTING:
When
feed
dog
contacts
edges
of
throat
plate
slots
(Fig.
19),
set
feed
dog
in
correct
position
as
instructed
below.
Throat
Plate
Slot
Feed
Dog
Feed
Dog
Throat
Plate
Slot
Fig.
19-a
Fig.
19-b
1.
If
feed
dog
contacts
the
edges
of
throat
plate
slots
(Fig.
19-a),
this
condition
can
be
corrected
by
moving
feed
dog toward
left
or
right,
as
required,
after
loosening
two
nuts
on two
screw
centers.
a.
To
move
feed
dog
toward
left,
loosen
screw
center
at
left
end
of
feed
rock
shaft
(Fig.
20),
as
required,
and
tighten
the
other
screw
center
an
equal
amount.
b.
To
move
feed
dog
toward
right,
loosen
screw
center
at
right
end
of
feed
rock
shaft,
as
required,
and
tighten
the
other
screw
center
an
equal
amount.
Feed
dog
should
travel
midway
between
sides
of
throat
plate
slots.
Screw
centers
must
hold
feed
rock
shaft
snugly
in
place
without
binding.
Securely
tighten
both
screw
center
nuts.
Loosen
~
Fig.
20
2.
If
feed
dog
contacts
the
edges
of
throat
plate
slots
at
an
angle
(Fig.
19-b),
correct
its
setting
as
instructed
below.
a.
Tip
machine
back
and remove
bed
plate
by
pushing
it
from
the
underside
with
the
point
of
a
screwdriver.
-
16
-

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
b. Loosen the two feed dog screws. (Fig. 21)
c. Set feed dog in correct position and securely tighten the two screws.
d. Replace bed plate and press it firmly in place.
Feed Dog Screw
Fig. 21
TO SET PRESSER BAR AT CORRECT HEIGITT
CHECK:
1. When presser bar is in its raised-position there should be a clearance
of 6.35 mm between underside of presser foot and top surface of throat
plate. (Fig. 22)
2. When presser bar is at its highest point and needle bar at its lowest,
top of presser foot should clear the lower end of needle bar.
SETTING:
1. Remove needle, and loosen presser bar pressure regulating thumb screw to
decrease spring tension.
2. Turn machine pulley toward you to lower feed dog below throat plate
surlace.
3. Raise presser bar lifter and loosen presser bar guide bracket set screw.
4. Place a block approximately 6.35 mm thick on top of throat plate, and
bring presser foot down to rest finnly upon the block. (Fig. 22)
S. Make sure the presser bar guide bracket is firmly in contact with presser
bar lifter, then lightly tighten guide bracket set screw. (Fig. 23)
- 17 -

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
6.
Remove
block,
lower
presser
bar
lifter,
and make
certain
presser
bar
is
positioned
correctly
so
that
needle
will
locate
centrally
between
the
toes
of
th.e
presser
foot,
7.
Securely
tighten
guide
bracket
set
s~rew-.
8.
Raise
presser
bar
lifter,
turn
machine
pulley
and make
sure
lower
end
of
needle
bar
does
not
interfere
with
presser
foot.
Press
Down
Against
Presser
Bar
Lifter
6.35
mm
r
Fig.
22
Fig.
23
TIMING
THE
FEED
Presser
Bar
Guide
Bracket
Set
Screw
Fig.
24
The
motion
of
feed
dog
in
relation
to
the
needle
should
be
as
follows.
1.
The
feed
dog
should
rise
above
throat
plate
surface
when
needle
rises
approximately
half
way
of
its
upward
stroke.
(Fig.
25-a)
2.
The
feed
dog
should
start
to
move
forward
(away from you)
just
before
the
needle
reaches
its
highest
point.
(Fig.
25-b)
3.
The
feed
dog
should
be
descending
and
just
about
to
go below
the
throat
plate
surface
when
needle
descends
to
a
point
level
with
the
top
surface
of
throat
plate.
(Fig.
25-c)
-
18
-