5-8) Lower (Bobbin) Threading And Tension Adjustment - SunStar SWF/C Series User Manual

5-8) LOWER (BOBBIN) THREADING AND
TENSION ADJUSTMENT
1) Lower Threading
① Use cotton yarn (#80－#120) for your lower thread.
② Threading the bobbin:
ⓐ Insert the threaded bobbin into the bobbin case with
the thread coming out from the case slot. Pull the
thread through the thread guide. Check if the bobbin
is rotating ([Fig.5-17]).
ⓑ Thread the lower thread holder and trim the thread
to 3-4cm before inserting the bobbin and the case
into the hook assembly. Long tail can cause the
thread to tangle during stitching.
[CAUTION 1]
Direction of the Bobbin Rotation
Make sure that the bobbin rotates clockwise
when you pull the thread holding the bobbin case
in your left hand([Fig 5-17]).
2) Lower Thread Tension Adjustment
Adjust the tension of the lower thread using the nut on the
tension spring on the bobbin case. Turn the nut clockwise
to increase the tension and counterclockwise to decrease
the tension.
[CAUTION 2]
For adequate bobbin thread tension, hold a thread
from the bobbin and jiggle the bobbin case lightly up
and down([Fig 5-18]). The case should drop and the
tension should be 25-35g.
3~4 cm
Screw
Tension spring
5-13
Lower thread
holder
Slot
Bobbin
Thread guide
[Fig.5-17]
driver
Bobbin case
[Fig.5-18]