41
4) How to Adjust the Lower Thread
Tension
If you turn the screw
②
on the spring plate
①
of the hook
clockwise, the lower thread tension would increase. On
contrary, if you turn the screw
②
on the spring plate
①
of the
hook counter-clockwise, the lower thread tension would
decrease.
①
3) How to Adjust the Upper Thread
Tension
As in Figure, turning clockwise the tension adjustment nuts
③
,
④
of the major thread control assembly
①
and the
auxiliary thread control assembly
②
respectively makes the
upper thread tension stronger and turning counter clockwise
makes it weaker.
① ③
④
②
[ Fig. 52 ]
[ Fig. 53 ]
②
Sewing Type
Cause
Troubleshooting
Good sewing in balance
Upper thread tension is too weak
Lower thread tension is too strong
Upper thread tension is too strong
Lower thread tension is too weak
Make upper thread tension strong or make
lower thread tension weak
Make upper thread tension weak or make
lower thread tension strong