Adjusting The Thread Tension - JUKI PS-800-12080 Instruction Manual

4-5. Adjusting the thread tension

❶ ❶
❷ ❷
❹ ❹
❺
A
B
(1) Adjusting the needle thread tension
Thread tension controller No. 1 ❶
❸ ❸
Thread tension controller No. 2 ❸
Fig. A
Fig. B
Fig. C
Fig. A: Threads are interlaced together accurately at
Fig. B: Needle thread tension is too low or bobbin
Fig. C: Needle thread tension is too high or bobbin
(2) Adjusting the bobbin thread tension
1) Turn tension adjusting screw ❺ clockwise (in
– 17 –
When the tension disk of thread tension controller
No. 2 ❸ is loosened, such a small tension as to
control the thread trimmer has to remain. The re-
maining tension is produced by tension controller
❶ . It is possible to determine the length of thread
trailing from the needle after automatic thread
trimming by adjusting nut ❷ of the thread tension
controller. The length of thread trailing from the
needle is reduced by turning nut ❷ clockwise (+).
It is increased by turning nut ❷ counterclockwise
(-).
The tension (applied to the thread coming from
the needle) controlled with thread tension con-
troller No. 2 ❸ should be set as low as possible
so that the needle thread and bobbin thread are
interlaced together at the center of material thick-
ness (Fig. A). If the thread tension is excessively
high when sewing a light-weight material, the ma-
terial may become wrinkled or thread may break.
The tension applied to the thread coming from the
needle is increased by turning nut ❹ clockwise
(+).
It is decreased by turning nut ❹ counterclockwise
(-).
the center of material thickness.
thread tension is too high.
thread tension is too low.
direction A) to increase or counterclockwise (in
direction B) to reduce the bobbin thread tension.
Recommended value: Approximately 25 g
The bobbin case will come down slowly by its
dead weight by holding it as illustrated in the fig-
ure.