– 58 –
Troubles
Causes
Checking
Corrective measures
Both needle and bobbin
t h r e a d c a n n o t b e
trimmed.
Threading device fails to
work.
Protruding amount of the
threading plate is too
small.
C l o t h t r e a d s n e e d l e
thread at the start of
sewing.
The blades of moving knife
and waiting knife have
been improperly adjusted.
Waiting knife pressure is
excessively low.
Moving knife fails to work.
Presser foot drops from
cloth at the time of thread
trimming.
Refer to “(18) -3) Knife pressure”.
Refer to “(18) -3) Knife pressure”.
Adjust the synchronizer timing.
Refer to “(18) -6) Most advanced
position of the waiting knife and
the cam timing”.
Air pressure is excessively low.
Adjust the air pressure (Adjust it
to 0.5 Mpa or more.)
Perform thread trimming on cloth.
Turn ON the threading switch.
Refer to “(19) -1) Threading
device”.
Adjust so that cloth does not tread
needle thread.
From the previous page
4
Needle thread remains on
cloth at the start of sewing.
