Singer Centurion 121C - CHECK SPRING SETTING; TENSION ADJUSTMENT

From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
CHECK SPRING SETTING
HEIGHT -
With
machine
threaded,
turn
handwheel
in
direction
of
machine
rotation. As
take-up
lever
begins
to rise, the
check
spring
should
dip
slightly, then return to its
origi-
nal
position
(Fig. A). When the thread
take-up
lever
approaches
the top of
its
stroke
the
check
spring
should
be
drawn
all the
way
down
(Fig. B). As
take-up
descends
the
check
spring
should
return to its
original
position.
To
adjust
height, loosen
locking
set
screw.
Rotate
entire
tension
assembly
as required,
and retighten set
screw.
FIG. A
TENSION
Tension
Assembly
Locking
Set
Screw
Tension on the
check
spring
should
be
sufficient
to
ensure
action
at top speed,
but
still
light
enough to
allow
spring
to be
drawn
all the way
down
before
any
thread
is
drawn
through
the tension
assembly.
To adjust,
securely
tighten
set
screw
(Fig.
A).
Hold
thumb
nut
stationary
(Fig. C).
Using
screwdriver,
turn
tension
stud
clockwise
to
increase
tension
and
coun-
terclockwise
to decrease.
14
FIG. B
,--
Thumb
Nut
Stud
/
FIG. C
/
/