Mitsubishi PLK-E1008H, Technical Manual

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6-6. Adjustment of the thread tension
The thread tension between the upper and bobbin thread should be balanced in the best
condition.
When the upper thread tension is well balanced with the bobbin thread tension, the both threads
are interlocked along the center line of fabric layers as shown on the below figures.
NOTE
Normally weaker bobbin thread tension bring better sewing quality.
So it is prefer to set bobbin thread tension first and then set upper thread tension.
6-6-1. Bobbin thread tension
○ × ×
Well balanced
tension The upper thread is tight
or the bobbin thread is
l
The upper thread is
loose
th b bbi th d i
(1) Loosen the screw (NO. ). Adjust the bobbin
thread tension with the thread tension adjusting
screw (NO. ).
To increase the bobbin thread tension, Turn the
screw to the clock-wise(A).
To decrease the bobbin thread tension, turn the
screw to the counterclockwise (B).
(2) After adjustment, fasten the screw(NO. ).
6-6-2. Upper thread tension
Adjust the upper thread tension based on the
bobbin thread tension.
For this adjustment, turn the thread tension
adjusting nut (NO. ).The upper tread tension
becomes tight if turn the thread tension adjusting
nut (NO. ) to the clockwise, and the upper thread
tension becomes loose if turn it to the
counter-clockwise
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