– 154 –
Troubles
Cause (1)
Cause (2)
Checking order and adjusting method
4. Thread breakage
Needle thread loop falls down.
Needle thread loop falls down.
Scratches on the inner hook
Thread enters into the shuttle.
Scratches on the shuttle driver
Clearance between the shuttle driver and the inner
hook is too small.
Scratches on the needle hole guide
Feed timing is too fast.
Scratches on section
A
(Contact of the inner hook
and the needle)
Scratches on section
B
(Scratches occur when
the needle is bent or broken.)
Scratches on section
C
(Needle scratches the
inner hook when removing the inner hook.)
Scratches on section
D
Position of the shuttle upper spring is wrong.
Blade point section
A
of the inner hook is round.
Position of the shuttle is wrong.
Needle thread tension is too low.
Thread take-up spring tension is too low.
Length of the remaining needle thread is too long.
Attach the needle with the long groove orienting slightly to the
right by approximately 20˚.
Change the feed timing using the memory switch.
After polishing the blade point of the inner hook with oil-stone,
polish it with polishing powder. Properly adjust the clearance
between the needle and the inner hook.
After polishing the blade point of the inner hook with oil-stone,
polish it with polishing powder.
After polishing the blade point of the inner hook with oil-stone,
polish it with polishing powder.
After polishing the blade point of the inner hook with oil-stone,
polish it with polishing powder.
Properly adjust the position of the shuttle upper spring.
Replace the inner hook.
Properly adjust the position of the shuttle.
Properly adjust the needle thread tension.
Properly adjust the thread take-up spring.
Properly adjust the tension controller No. 1.
Remove the scratches and polish with buff, or replace the shuttle
driver.
Properly adjust the clearance between the shuttle driver and the
inner hook.
Remove the scratches and polish with buff, or replace the needle
hole guide.
A
B
C
D
A
