EasyManua.ls Logo

JUKI LBH-784 - Troubleshooting: Causes and Remedies

JUKI LBH-784
11 pages
Save Page as PDF
Print Icon
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Loading...
28.
TROUBLE,
CAUSE,
AND
REMEDY
Trouble
Cause
Remedy
1.
Needle
thread
is
broken.
(1)
The
tension
of
the
tension
controller
No.
2 is
too
tight.
(2) The tension or the stroke of the take-up
spring
is
too
great.
(3)
Blade
point
of sewing
hook
has
burr
or
scratches.
(4)
Poor
timing of the sewing
hook.
(5)
The
thread
path
has
scratches.
(6)
The
needle
is
too
thin.
0
Decrease
the
tension
of
the
tension
controller
No.
2
o
Decrease
the
tension
or
the
stroke
of
the
take-up
spring.
o
Buff
the
blade
point
of
the
sewing
hook,
or
replate
the
sewing
hook,
o
Readjust
the
sewing
hook's
timing
by
the
timing
gauge,
o
Buff
the
thread
path
by
cloth
files, etc.
o
Replace
by a
thick
needle.
2.
Thread
slips
out
of
the
needle.
(1) The needle thread trimmer opens
too
early.
(2) The needle thread trimmer opens when
the
work
clamp
check
is
comming
down.
(3)
The
whip
stitch
is
not
formed
at
the
start
of
sewing.
(4)
Wrong
threading.
0
Move
back
the
needle
thread
trimmer
driving
plate
B.
o
Move
back
the
needle
thread
trimmer
driving
plate
B.
o
Decrease
the
tension
of
the
tension
controller
No.
1.
O
Perform
correct
threading.
3.
Wobbling
stitches
are
formed
in
the
overedging
seams.
(1)
The
tension
disc
No.
2 is
too
loose.
(2)
The
tension
and
stroke
of
the
take-up
spring
is
not
enough.
(3)
Bobbin
thread
tension
is
too
high.
o
Increase
the
tension
of
the
tension
disc
No.2.
o
Readjust
the
take-up
spring.
o
Decrease
the
bobbin
thread
tension
(15
to
20g
for
purl
stitches).
4.
Wobbling
stitches
are
formed
at
the
start
of
sewing,
5.
The
needle
thread
at
the
first
bar
tacking
comes
out
and
lumps
on
the
bottom
of
cloth.
(1)
The
tension
disc
No.
1 is
too
loose.
1
(2)
The
position
of
the
needle
thread
trimmer
is
too
high.
1
(3)
The
stroke
of
the
take-up spring is
too
great.
(1)
The
tension
disc
No.
1 is
too
loose.
(2)
The
bobbin
thread
tension
is
too
high.
o
Increase
the
tension
of
the
tension
disc
No.
1
(15
to
30g).
o
Lower
the
trimmer
as
low
as
possible,
provided
it
does
not
come
in
contact
with
the
work
clamp
check,
o
Decrease
the
stroke
of
the
take-up
spring,
and
increase
the
spring
pressure.
o
Increase
the
tension
of
the
tension
disc
No.
1.
o
Decrease
the
bobbin
thread
tension
(15
to
20g).
6.
Stitches
float
over
cloth.
(1)
Bobbin
thread
tension
is
not
enough.
(2)
Bobbin
thread
slips
out
of
the
thread
path
on
the
bobbin
case.
o
Increase
the
bobbin
thread
tension,
o
Properly
thread
the
bobbin
case.
7.
Stitches
are
skipped.
(1)
The
work
clamp
check
is
too
large
for
the
buttonhole.
(2)
The
cloth
is
made
of
light-weight
materials.
o
Change
the
work
clamp
check
with
a
smaller
one.
o
Delay
the
timing
of
the
needle
and
the
sewing
hook.
(Lower
the
needle
bar
by
approx.
0.5mm
(1/2"))
I
From the library of: Superior Sewing Machine & Supply LLC

Table of Contents

Related product manuals