Singer Centurion 121D - Page 47

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
ASSEMBLY SEQUENCE
1.
Insert
connecting
rod,
slide
block
and
lower
clamp
assembly
into
arm
and
bed
cast-
ing.
2.
Move feed
rock
shaft
from
left
to
right
through
lower
connecting
rod
clamp
assem-
bly.
3.
Set
shaft
end
flush
with
left
bearing
face. Move
collar
up
to
bearing
and
tighten
set
screws.
4.
Move
second
collar
up to
bearing
shown,
to
allow
.001
inch
maximum
end
play,
and
tighten
set
screws.
5.
Set feed
reversing
lever
and
drive
assembly
(not
shown)
at
neutral
position
(no
feed).
Tighten
feed
reversing
crank
pinch
screw
(shown).
6.
Insert
wicking
through
connecting
rod as
shown.
7.
Install
crank
shaft
arm,
connecting
rod
upper
clamp
assembly
and
collar.
8.
Bring
collar
up
to
bearing
face
to
allow
.001"
maximum
end
play
of
crank
shaft
as-
sembly
and
tighten
set
screws.
9.
Knot
end
of
wicking
and
place
into
pinched
clamp
as
illustrated.
10.
Install
needle
bar
frame
and
thread
take-up
mechanism
as
shown
on page
37
with
two
additions.
First -
mount
and
fasten
conventional
throat
plate
(with
needle
hole).
Second
-
line
up
crank
shaft
stud
with
needle
bar
frame
drive
link
as shown.
11.
Assemble
needle
bar
frame
drive
link
retaining
ring.
12.
Assemble
presser
bar
lifting
shaft,
collar
and
crank.
13.
Bring
collar
up
to
crank
shaft
assembly
to
allow
.002"
maximum
end
play
and
tighten
set
screws.
14. Position
crank
set
screws
on
flats
pro-
vided
and
tighten.
15.
Replace
tension
releasing
lever,
spring,
mounting
screw
and
lifting
link
assembly
with
screw
as
shown
on
page
36
as
items
3 and
5.
16.
Replace
thread
take-up
lever
guard
and
thread
guide
complete
Assemble
pretensioner
if
required
17.
Replace
thread
tension
assembly
with
releasing
pin
and
tighten
tension
mounting
screw.
18.
Assemble
presser
bar
system
and
face
plate
assembly
as
shown
on
page
38
with
one
exception.
Item
6,
presser
bar
pressure
lever
adjusting
screw,
has been
premounted
45