Singer 271K - Page 14

PRE-TENSION CONTROL
Since the tension on the needle thread ac
tuated by the middle tension device, shown in
Fig. 28, is released during bar stitching, the
pre-tension control is of primary importance
during this portion of the sewing cycle.
Tension on needle thread due to pre-tension
control should be just enough to prevent sewing
hook from stealing thread, at this time. Adjust
this tension by turning knurled nut on pre-ten
sion control, OS shown in Fig. 28, so that even
the first three or four stitches immediately
followingthe bar stitchingpull up into an attrac
tive purlstitch. Too light tension causes these
stitches to be loose or to look similar to whip
stitches. Too heavy tension may break thread.
See "SPECIAL INSTRUCTIONS FOR MACHINE
271K2", starting on page 33.
NEEDLE THREAD TAKE-UP SPRING
The tension on take-up spring, shown in
Fig. 29, during
downward stroke of needle,
should be sufficient to take
up slack of thread
until eye of needle reaches the material.
To adjust, loosen take-up spring set screw
and turn ONLY the tension stud, as instructed
in Fig. 29. Then securely tighten set screw.
TOP CORD FINGER ON MACHINE 271K4
HEIGHT SETTING: Cord finger, shown in
Fig. 30, should just clear top surface of clamp
check, during movement of finger
from right
side to front of needle and return.
To adjust, loosen screw, shown in Fig. 30.
Raise or lower finger, as required.
SECURELY
tighten screw.
14
MORE TENSION
PRE-TENSION
CONTROL
BAR
RIGHT WRONG
MIDDLE
.^l'ess tension /SivfcE'^
TENSION
RELEASEDI
DURING
BAR STITCHING
Fig. 28. Regulating Pre-Tension
-aii
TURN STUD
LESS TENS ON
,11
MORE TENSION
TAKE-UP
SPRING
AT REST
LOOSEN
TO ADJUST
Fig. 29. Adjusting the Talce-up Spring
CLEARANCE-^
LOOSEN TO ADJUST
HEIGHT OF
CORD FINGER
CLAMP CHECK
Fig. 30. Cord Finger at Correct Height
on Machine 271K4
r\
From the library of: Superior Sewing Machine & Supply LLC