Singer 271K - Page 28

UNDER-THREAD CUTTING BLADE
REMOVAL: Turn machine over on its hinges and
remove bobbin case stop screw and bobbin case
stop, shown in Fig. 73. Remove the two blade-
holding screws and under-thread cutting blade,
shown in Fig. 72.
REPLACEMENT: Place new cutting blade in
position shown in Fig. 72, with its cutting edge
between pull-off finger and needle plate. Fasten
blade with two screws, moving blade
as far as it
will go toward left side of machine bed. Make
certain blade edge is parallel with knife slit in
needle plate. Then securely tighten blade-holding
screws.
Replace bobbin case stop and screw. Adjust
as instructed next.
BOBBIN CASE STOP
HORIZONTAL POSITION: Bobbin cose stop
should be
set with its rear edge flush with rear
surface of position finger on bobbin
case base,
as shown at top of Fig. 73.
To adjust, loosen hinge stud
set screw,
shown in Fig. 72 and move bobbin case stop,
opener bracket, bracket collar and hinge stud
together, as required. Tighten hinge stud set
screw.
VERTICAL POSITION: Turn machine pulley until
bobbin case stop is in its lowest position, as
shown in Fig. 73. At this position, there should
be a clearance of approximately .005 inch be
tween notch in bobbin cose base and bottom
surface of stop, as shown in Fig. 73.
To adjust, loosen large screw, shown in Fig.
73. Move stop as required to obtain clearance
and retighten large screw.
BOBBIN CASE OPENER BRACKET HINGE
STUD is a part of oiling system and must be
positioned to align internal oil passages. Cor
rect alignment is obtained when stamped mark,
5hown in Fig. 72, on its face, is in 6 o'clock
position.
FRONT HOOK SHAFT BUSHING is also
port of oiling system and stamped mark on its
face must also be in 6 o'clock position, as
shown in Fig. 72.
UPPER-THREAD CUTTING
AND CLAMPING BLADES
("SPECIAL INSTRUCTIONS" FOR MACHINE
271K2, start on page 33.)
28
UNDER-THREAD
CUTTING BLADE
BLADE
HOLDING
SCREWS
HINGE STUD
MARK
OPENER
BRACKET
HINGE PIN
SET SCREW
COLLAR
Ftg. 72. Under-Thread Cutting Blade
HORIZONTAL POSITION
VIEWED FROM TOP
REAR EDGE OF
BOBBIN CASE STOP
' riTSQ
CONNECTING
ROD SCREW
BOBBIN CASE BASE-^-^ -__
BOBBIN CASE
STOP SCREW
BOBBIN CASE STOP
AT LOWEST POSITION
PULL-OFF
FINGER
r?^
NEEDLE
PLATE
mark ON
FRONT
HOOK SHAFT
BUSHING
POSITION FINGER ON
,BOBBIN CASE BASE
FLUSH WITH REAR
EDGE OF BOBBIN
CASE STOP
CHECK
HOLDER
SCREW
CLAMP
CHECK
V
POSITION
FINGER
VERTICAL POSITION
:.005 CLEARANCE)
NOTCH
Fig. 73. Bobbin Case Stop
BLADE
HOLDER
SCREW [0
rf
REMOVE MAT
SCREW AND
SWING MAT
OUT
UPPER THREAD
UTTING BLADE
CLAMPING
BLADE
Fig. 74. Upper-Thread Cuttingand Clamping Blades
From the library of: Superior Sewing Machine & Supply LLC