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Trouble
7. Thread breakage at needle entry
or idle stitching.
8. Staggering stitches
Some stitches stagger, whereas
they should be aligned.
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Cause (1)
7-1) The needle has improperly
been installed.
7-2) The knife thread guide has
improperly been positioned.
7-3) The needle bar is too low.
8-1) The tension of the needle
thread is too high.
8-2) The needle is defective.
8-3) The sewing speed is too high.
8-4) Feeding is inappropriate.
Cause (2)
1-A) The orientation of the needle is
wrong.
2-A) The needle is bent.
2-B) The needle tip is blunt.
2-C) Needle is too thin.
2-D) The needle is too long.
4-A) The parallel level of the feed
dog is inappropriate.
4-B) The feed dog is aslant mount-
ed.
4-C) The feeder bar has a backlash
in the right-left direction.
Check and corrective measures
Attach the needle so that the long groove of
the needle faces exactly to the left or slightly
away from the operator as illustrated.
Accurately position it so that needle enters the
center of the opening.
Raise the needle bar.
Wrap the thread around the needle.
Reduce the tension of the needle thread.
Replace the needle.
Replace the needle.
Use a thicker needle. For a KN needle (single
needle), use a double needle.
Use a shorter needle or a needle with longer
shank (DA x 1)
Reduce the sewing speed.
Replace the current feed dog with new one.
Mount the feed dog appropriately.
Eliminate the backlash in the state of slightly
pressing the top, bottom, and horizontal feed-
er bar pins.
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