Singer class 251 - Needle Bar Removal and Replacement; Presser Bar Removal and Replacement

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
34
4.
Remove
the
locking
screw
Q2, Fig.
48
from
the
center
of
the
up-
right
arm
shaft,
by
turning
it
over
toward
the
left
(counterclock-
wise).
5.
Remove
the
impeller
P2,
by
turning it over
toward
the RIGHT (clock-
wise)
to
loosen
it,
as
instructed
in
Fig.
48.
CAUTION: -
The
impeller
P2
is
designed
to
be
screwed
to
the
shaft
by
means
of
a
LEFT-HAND
THREAD
and
must
be
turned over
toward
the
right to be loosened.
Avoid
damage
to
this
impeller,
as
the
efficient
automatic
lubrication
of
the
machine
is
dependent
upon
it.
TO LOOSEN
Fig. 48. Oil
Pump
6.
Remove
the
three
screws
T2, Fig.
48.
7.
Carefully
pull
1he
old
oil
pump
body
off
the
lower
end
of
the
upright
arm
shaft.
TO
REPLACE
THE
OIL PUMP
Replace
oil
pump
in
the
following
manner:-
1.
Place
oil
pump
body
on
underside
of
machine
bed,
so
that
position
pins
V2,
slip
into
proper
holes
in
machine
casting
as
shown
in
Fig.
48.
2.
Replace
and
securely
tighten
the
three
screws
T2.
Make
certain
that
machine
turns
freely
as
screws
are
tightened.
3.
Carefully
replace
impeller
P2, turning it over toward the
LEFT
to
SCREW
it
on
arm
shaft
(see
CAUTION
above).
4.
Make
certain
that
impeller
P2
is
not
so
tight
that
it
will
bind
arm
shaft
and
that
impeller
clears
both
top
and
bottom
of
in-
terior
of
oil
pump
body,
then
lock it in
position
by
means
of
lock-
ing
screw
Q2.
5.
Replace
pump
cover,
screen
and
frame
02
and
four
screws
N2,
Fig.
47.
Securely
tighten
screws
N2.
6.
Replace
two
oil
pipes
in oil
pump
body,
as
shown
in
Fig.
48,
and
securely
tighten
sleeve
nuts
S2.
35
TO REMOVE
AND
REPLACE
THE
NEEDLE
BAR
Remove the needle
bar
in
the
follow-
ing
manner:-
].
Remove
needle
and
needle
set
screw
or
needle
clamp.
2.
Remcve
face
plate.
3.
Loosen
clamping
screw
M,
Fig.
49
4.
Loosen
screw
R2
sufficiently
to
allow
needle
bar
to
pass,
then
slip
needle
bar
up
through
both
needle
bar
bushings
and
out
of
machine.
If
it
becomes
necessary
to
remove
upper
needle
bar
bushing
N,
Fig.
49,
first
remove
screw
R2
and
take-up
lever
oil
guard
W2.
Then
loosen
set
screw
P
and
drive
bushing
N
down
and
out
of
head
of
machine.
Use a
13/32
inch
driving
pin.
Before
replacing
needle
bar,
replace
upper
needle
bar
bushing
N,
by
driv-
ing
it
down
into
hole
provided
for
it in
head
of
the
machine.
Make
certain
top
of
bushing
N
is
level
with
top
of
arm.
Tighten
set
screw
P.
Replace
needle
bar
in
the
following
manner:-
1. Slip
needle
bar
down
through
both
Fig.
49.
Removing
and
Replacing
bushings
in
head
of
the
machine.
Needle
Bar
and
Presser
Bar
Tighten
screw
M.
2.
Replace
needle
clamp
and
needle.
See
page
8.
3.
Set
needle
bar
at
correct
height
and
replace
face
plate,
as
in-
structed
in
last
paragraph
on
page
19.
4.
Replace
oil
guard
W2
and
fasten
it
securely
to
bushing
with
set
screw
R2.
TO REMOVE
AND
REPLACE
THE
PRESSER
BAR
To
remove the presser
bar:-
1.
Remove
presser
foot
and
face
plate.
2.
Remove
presser
bar
regulating
thumb
screw,
X2,
Fig.
49
with
upper
section
of
presser
bar
from
the
head
of
the
machine.
3. Loosen
clamping
screw
V
and
screw
AS
and
slip
guide
bracket
T
up
off
presser
bar
and
out
of
machine.
4.
Slide
presser
bar
up
through
bushing
and
out
of
machine.
To
replace the presser
bar:-
1.
Slip
presser
bar
down
through
lower
presser
bar
bushing.
2.
Replace
guide
bracket
T
as
shown
in
Fig.
49.
3.
Replace
pres,;er
foot.
4.
Replace
presser
bar
regulating
thumb
screw
X2
with
upper
section
of
presser
bar.
5.
Set
the
presser
bar
at
the
correct
height,
as
instructed
on
page
21.
Tighten
screw
V.
6.
Tighten
screw
AS
making
sure
that
slack
thread
regulator
BS
just
clears
the
casting.
Replace
face
plate,
as
instructed
on
page
19.