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Adjustment Procedure
１. Hold the bobbin so that it turns to the right and insert it in the
bobbin case. (See Drawing.)
２. Pass the thread through the threading port A of the bobbin
case. When the thread is pulled in the direction of B, it can be
pulled toward the threading port C passing beneath the thread
tension spring.
３. Examine if the bobbin turns in the direction of the arrow when
the bobbin thread is pulled.
About the standard part numbers(DDL-8000A*-S
Part name
Bobbin case
Bobbin case with idling
prevention spring
Bobbin
Bobbin case with idling prevention spring
The DDL-8000A Series employs the bobbin case with an idling prevention spring.
Adjustments of idling prevention spring tension can be carried out in the procedures below.
If bobbin idling occurs, increase the idling prevention spring tension
When the bobbin runs idle
When the thread is not well tightened
[Adjustment of idling prevention spring tension]
If there is a problem of bobbin idling or uneven sewing at high or low speed, use of a bobbin case with an
idling prevention spring is effective.
(1) Insert an old needle as illustrated and remove the spring by lifting it up.
(Suggestion: Use the thumb to prevent the spring from popping out.)
(2) The spring tension can be changed by changing the height of the arch-shaped section of the spring.
(Make sure not to permit the free end of the spring to come out of the bobbin case.)
(3) Firstly, set the ear ❶ and insert the needle. Then, settle the ear ❷ is the state that the center part of
the spring is lifted.
(4) When a bobbin case with an idling prevention spring is used, it should be inserted in the winding
direction as illustrated.
(Unevenness in sewing at high or low speed)
When sewing seems to be too tight
at low speed:
When sewing seems to be too
weak at low speed:
□□
)
MS type
11038759
11038700
22932909
(Made of iron)
→ Increase the tension of the idle-prevention spring.
→ Decrease the tension of the idle-prevention spring.
Adjust the bobbin thread tension and the idling
→
prevention spring tension to be strengthened.
Adjust the bobbin thread tension and the idling
→
prevention spring tension to be weakened.
– 16 –
Results of Improper Adjustment
○ If the direction of clockwise winding
is adopted, variation is lessened
possibly caused by a change in the
amount of bobbin thread.
SH, SJ type
40000264
11038700
22932909
(Made of iron)
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