21.TROUBLECHART
PROBLEM
Breaking
lower
thread
Skipping
stitches
h
equiJr
stitches
The
material
not
fed
correctly
PROBABLE
CAUSE
Thread
not wound
evenly
on
the
bobbin
or
not
drawn
up
correctly
Lower
thread
tension too
tight
Lint
stuck
in
the
bobbin
case
and
inside
the tension
spring
Needle
not
fully
inserted
Needle
bent
Size
or
type
of
needle
and
thread
not
suitable
for
the
material
Incorrect
upper
threading
Too
much
oil
on
the
hook
Incorrect
size
of
needle
for
the
material
Upper
thread
tension
too
loose
Incorrect
lower
tension
Pattern
selection
dial
not
set correctly
Incorrect
feed
dog
height
Lint
stuck
on
the
feed
dog
CORRECTION
P.10,
P.15
P.12
Remove
lint
and
fluff
with
a
cleaning brush
P.
6
P.
6
P.16
P13
P
46
P.16
P.20
P.12
P.17
P.12
P.45