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Useful Hints
Causes and Elimination of Little Troubles
Blocked Shullla
If the machine should
fail to run either for¬
ward or in reverse or
if an abnormally loud
noise is heard, a thread
has become jammed in
the shuttle race owing
to
faulty
manipula¬
tion.
In
such
eases,
the race can easily be
cleared. Raise needle
bar to its extreme po¬
sition, depress spring
lever member 66 (on
the left of the shuttle
race)
with
left-hand
thumb so that the lock¬
ing bridge 66 can be swivelled down together with the shuttle race cover 6?. After
removal of bobbin case and shuttle, it will be easy to remove jammed thread ends and
dust from the shuttle race. Do not use hard instruments, such as screw-drivers, etc., to
avoid damaging the shuttle race. After cleaning, first replace shuttle, and swing the
locking bridge 66 and shuttle wall cover 67 into position shown in Fig. 78. Then press
with the thumb on the spot marked with an arrow until the locking bridge rams home,
and finally replace bobbin case. Make sure that the locking bridge is properly engaged.
Top Thread Broakagt
Needle of inferior quality, badly polished needle.
Needle not properly inserted. Long groove must face front.
Needle blunt or bent.
Needle too fine in relation to thread used.
Top thread tension too tight.
Thread passages not polished.
Thread control spring broken.
Needle hole in throat plate damaged by needle, requires repolishing.
Shuttle point has become too sharp by needle action (Call mechanic).
Shuttle race not oiled.
Inferior thread or knotted thread.
Thread dried out in storage. Threads should never be kept in heated rooms.
Bollom Thread Breakage
Bottom thread tension too tight.
Bottom thread not properly wound on bobbin.
Fi*. 7b
101
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