Mitsubishi LU2-430 User Manual

Trouble
After trimming,
needle thread is
too short.
Stitches skip at
start of sewing.
5 to 6 stitches
after start of
sewing, bobbin
thread is broken.
Cause
1. Working stroke of slack
thread take-up spring is too
large.
2. Thread is not smoothly
passed through thread hand
ling parts.
3. Opening degree of needle
thread tension disc is in
sufficient.
4. Thread is caught in thread
retainer.
5. Pretension is too high.
6. Thread is broken by mova
ble knife and bobbin thread
retaining spring.
7. Needle thread tension re
leasing timing is improper.
1. Bobbin thread is out of
bobbin thread retaining
spring.
2. After thread trimming, nee
dle thread is too short.
3. Bobbin thread tension is too
high.
4. Slow start switch is turned
on.
5. Thread is wound 1 turn
around needle.
1. Bobbin thread tension is too
high.
2. Bobbin thread is entangled
due to idle running of
bobbin.
3. Thread is not smoothly
passed through feed needle
eye and throat plate, or is
damaged.
29
Corrective Action
Reduce working stroke
to the degree that sewing
performance is not ad
versely affected.
Polish thread handling
parts such as thread
retainer, needle thread
tension regulator, and
needle clamp.
Adjust needle thread ten
sion regulator.
Check threading of nee
dle thread.
Decrease pretension.
Buff end of bobbin
thread retaining spring.
Adjust cam of needle
thread tension regulator
cam.
1. Correct spring pressu
re and also movable
knife contact surface.
Check if idle running
prevention spring is in
side rotating hook.
Polish needle
throat plate.
eye and
Reference
Sec. 4 in P. 20
Sec. 4 in P. 9
Sec. 4 in P. 20
P. 23
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

Mitsubishi LU2-430 Specifications

General

Brand	Mitsubishi
Model	LU2-430
Category	Sewing Machine
Language	English