10. THREAD TENSION
10. THREAD TENSION
10-1. Adjusting the thread tension
Turn off the power switch before removing or inserting the bobbin case.
The machine may operate if the treadle is depressed by mistake, which could result in injury.
Good even stitches
Becomes weaker
Becomes stronger
37
Upper thread
Lower thread
0572M
Upper thread tension too weak or
lower thread tension too strong
0573M
Upper thread tension too strong
or lower thread tension too weak
0574M
2177M
Becomes weaker
Becomes stronger
3748M
CAUTION
<Lower thread tension>
Adjust by turning the adjustment screw (1) until the bobbin
case drops gently by its own weight while the thread end
coming out of the bobbin case is held.
<Upper thread tension>
After the lower thread tension has been adjusted, adjust the
upper thread tension so that a good, even stitch is obtained.
1. Lower the presser foot.
2. Adjust by turning the tension nut (2).
S-7220B
Increase the upper thread tension.
Decrease the lower thread tension.
Decrease the upper thread tension.
Increase the lower thread tension.