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Problem
9
Lower thread is tangled at
the sewing start.
Lower
thread
10
Upper and lower threads
are breaking.
11
Broken needles
Is the bobbin spinning direction correct when the lower thread is
being pulled?
Set the bobbin so that it turns in the opposite direction to the
rotary hook.
Is there too much thread
wound onto the bobbin?
The
amount should not be
more that 80 %.
Is the bobbin turning smoothly?
If the bobbin is not turning smoothly, replace the bobbin.
0751M
Is the needle bent or is the needle tip broken?
Replace the needle if it is bent or broken.
Is the needle properly installed?
If it is incorrect, install the needle correctly.
Is the machine properly threaded?
If it is incorrect, thread the thread correctly.
Is the upper or lower thread tension too weak or too strong?
Adjust the upper thread or lower thread tension.
Is the upper thread may be loose because the thread take-up spring
operating range is too small?
Adjust the position of the thread take-up spring.
Is the rotary hook, feed dog or other part damaged?
If they are damaged, smooth them with an oiled grindstone or
replace the damaged parts.
Is the thread path damaged?
If the thread path is damaged, smooth it with sandpaper or
replace the damaged part.
0471M
Is the material being pushed or pulled with excessive force during
sewing?
Is the needle properly installed?
If it is incorrect, install the needle correctly.
Is the needle bent, is the needle tip broken, or is the needle hole
blocked?
Replace the needle.
Is the needle and rotary hook timing correct?
Adjust the height of the needle bar.
Adjust the clearance between the needle and the tip of the
rotary hook.
Is the needle timing too advanced with respect to the feed dog?
Retard the needle timing.
Caution
It is extremely dangerous to leave any pieces of broken
needle sticking in the material. If the needle breaks, search
for all pieces until the whole of the needle is found again.
Furthermore, we recommend we recommend that through
steps be taken to account for such needles to comply with
product liability regulations.
0469M
Possible cause
bobbin
winding
S-1110A
11. TROUBLESHOOTING
Page
10
10
2124M
9
11
13
16*
*
*
9
19*
20*
19*
24
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