Publicidad
Trouble
Thread not trimmed
Thread ensnared
Cause
Fixed blade is blunt.
Thread trimmer lever spring
tension
weak and therefore
moving
blade
does
not
move completely to end.
Moving
blade
does
not
scoop
up
upper
thread.
Because
final
stitch
is
skipped, moving blade does
not scoop up upper thread.
Position
of moving
blade
faulty.
Thread take-up spring too
weak.
Poor
contact
between
needle
and
shuttle
hook.
Shuttle
race thread guide
does not separate
thread.
Upper thread tension
too
weak.
Thread tension poor
Thread take-up lever stroke
too large.
Lower thread
tension
too
weak.
Presser
lifter torque insuf
ficient.
Preeser does not rise
Brake
tension
spring
ten
sion too great.
Motor is in reverse.
Insufficient
oil
on
ball
presser plate.
Clutch does not engage,
and bar tacking cycle is
repeated
Clutch lever spring tension
too weak.
Check point
Edge of fixed blade.
Tension
of thread trimmer
lever spring.
Position
of
shuttle
race
thread guide.
Skipping of final stitch.
Position of moving blade.
Tension
of thread take-up
spring.
Needle bar stroke.
Position
of
shuttle
race
thread guide.
Upper thread tension.
Stroke
of thread
take-up
lever.
Lower thread tension.
Tension of low speed belt.
Tension
of
brake
tension
spring.
Rotational
direction
of
motor.
Ball presser plate oil.
Tension
of
clutch
lever
spring.
Remedy
Sharpen
or replace fixed
blade.
Replace
thread
trimmer
lever spring.
Install guide in straight line
with shuttle race body.
See
paragraph
"Skipped
stitches" for prevention of
same.
Adjust position of moving
blade.
Adjust tension and height
of thread
take-up
spring.
Adjust stroke of needle bar.
Install guide in straight line
with shuttle race body.
Adjust to appropriate
ten
sion.
Adjust
stroke
of thread
take-up lever.
Adjust to appropriate
ten
sion.
Adjust tension of low speed
belt.
Adjust
tension
of
brake
tension spring.
Set motor in normal
rota
tion.
Lubricate ball presser plate.
Move clutch lever spring to
second position.
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Publicidad
