5-6) Lower (Bobbin) Threading And Tension Adjustment - SunStar SWF/B Series User Manual

5-6) 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 bobbin into the bobbin case with the thread
coming out from the case slot. Pull the thread through
the thread guide. When you pull the thread, check if
the bobbin is rotating ([Fig.5-13]).
• 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 bobbin
thread to tangle during stitching.
[ Caution ]
Make sure that the bobbin rotates clockwise when
you pull the thread holding the bobbin case in your
left hand.
2) Lower Thread Tension Adjustment
Adjust the tension of the bobbin 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 ]
For adequate bobbin thread tension, hold a thread from the
bobbin and jiggle the bobbin case lightly up and down. The
case should drop and the tension should be 25-35g.
3~4cm
Adjusting screw
Tension
spring
Thread guide
Bobbin case
Lower thread
holder
Slot
Bobbin
[Fig. 5-14]
Driver
[Fig. 5-15]