SINGER 251 - Manual (Page 19)

1 9
HEIGHT
TO SET C H E C K S P R I N G
TENSION
HrOHER
LOOSEN
\ /
H
/£;
Fig. 30. Setting Height of
Check Spring
PREPARATION:
Thread the machine.
CHECK:
Turn machine pulley over toward operator slowly.
When take-up lever begins to rise, check spring G,
Fig. 30 m akes a slight dip and a return to its higher
position. Later, as take-up lever approaches top of
stroke, check spring G should be drawn all the way
down; setting the stitch. As lever descends, check
spring G returns to rest.
SETTING;
Loosen screw H, Fig. 30. Turn stud J, Fig. 30 (at the
same time turning entire tension assembly) either over
toward left to lower check spring and decrease its
movement, or over toward right to raise check spring
and increase its movement. Securely tighten set screw
H.
NOTE:
Under certain conditions of tacking, it may be
necessary to set the check spring higher than it is
otherwise normally set.
CAUTION;
Check spring height setting must be checked each
time a different foot is applied to machine.
Fig. 31. Adjusting Tension on
Check Spring
PREPARATION:
Thread the machine. Securely tighten set screw H,
Fig. 31. Make certain thumb nut is on stud J, Fig. 31.
CHECK;
Tension on check spring G, Fig. 31, should be suffi­
cient to ensure action at top speed; but still light
enough to permit itself to be drawn all the way down
(as take-up lever approaches height of stroke) before
any thread is drawn through the tension discs.
SETTING;
Using a large screwdriver in slot of stud J, turn
stud either over toward left to decrease tension or
over to right to increase it, as shown.
NOTE;
The tension on the check spring may require
different settings depending upon the size of thread
used. Heavier thread requires more tension to ensure
correct thread control.