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Adjustment Procedures
Results of Improper Adjustment
1) Adjustment of needle thread guide bar
Loosen the setscrew
of the needle thread guide bar
of
1
to
4
to adjust the height. After adjustments, fix the setscrew
.
o Lowering the needle thread guide bar
causes the needle thread
to be tightened.
o Raising the needle thread guide bar
causes the needle thread to
be loosened.
2) Adjustment of needle holder adjusting pin
Loosen the setscrew
of the needle thread holder adjusting pin
of
5
,
6
to adjust the height. After adjustments, fix the setscrew
.
Size
7
,
8
is for reference.
o Raising the needle thread holder adjusting pin
causes the needle
thread loop to be enlarged.
o Lowering the needle thread holder adjusting pin
causes the needle
thread loop to be diminished.
3) Adjustment of needle thread presser spring
Loosen the setscrew
to turn the spring holder
and make ad-
justments to secure the size of 2.5mm between the tip section of the
needle thread presser spring
and the head top of the screw
.
Then, tighten the setscrew
.
*
Role of the needle thread presser spring
The needle thread resistance is effective in stabilizing loop forma-
tion.
When the hand pulley is turned in reverse direction and then in for-
ward direction for starting, the needle thread once loosened is tensed
again by the function of the needle thread presser spring
. For this
reason, stitch formation is improved at the time of starting.
o More precise adjustment to the
standard size is needed for the
needle thread guide bar
as it is
positioned closer to the looper.
Otherwise, the thread tension may
become worse.
o Since the left and left middle
needles are located near the
looper, the needle thread holder
adjusting pin
has to be adjusted
to the standard size correctly. Oth-
erwise, loop formation will get
worse and stitch skipping may oc-
cur.
o If the needle thread presser spring
has no needle thread resis-
tance, stitch skipping may be
caused at the time of starting.
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com
