JUKI LU-1510N Engineer's Manual page 70

Troubles
Stitch skipping
2
Causes
Clearance between the
needle and the blade
point of hook is too large.
Needle-to-hook timing is
excessively advanced or
retarded.
Presser foot is rising.
Height of the needle bar
is improper.
Blade point of the hook
is blunt.
Improper type of needle
is used.
Hook needle guard is not
functioned.
Thread take-up spring
excessively works or the
stroke of the spring is too
small.
Feed timing is not proper.
Needle thread tension is
too high.
– 66 –
Checking
Check the clearance.
Check the specified
dimension.
Check the pressure of
the presser foot.
Check the lowest point of
the needle bar.
Check the blade point of
the hook.
Check the functional
amount of the needle
guard.
Corrective measures
Refer to "(7) Needle-to-hook
timing".
Refer to "(7) Needle-to-hook
timing".
Tighten the presser spring
regulator.
Refer to "(7) Needle-to-hook
timing".
Correct the blade point of the hook
or replace the hook.
Replace the needle with one
which is thicker than the current
needle by one count.
Refer to "(7) Needle-to-hook
timing".
Decrease the tension of the
t h r e a d t a k e - u p s p r i n g a n d
increase the stroke of the spring.
Refer to "(9) Feed cam timing".
Adjust the needle thread tension.