Adjusting Thread Tension; Lower Thread Tension; Upper Thread Tension - SunStar KM-2300 User Manual

6-3. Adjusting thread tension

[ Caution ]
·When inserting and removing bobbin case, make sure to turn off the power switch. Pressing pedal by mistake may result
in physical injuries or mechanical damages.
Sewing Type

6-3-1. Lower thread tension

1. Adjust tension by turning tension control screw① to the
extent that bobbin case falls by gravity when holding the
end of thread.

6-3-2. Upper thread tension

1. Adjust upper thread tension after adjusting lower thread
tension to make sure good sewing.
2. Move presser foot down.
3. Adjust upper thread tension by turning tension-adjusting
screw② of main thread controller.
Cause
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
Troubleshooting
Make upper thread tension strong or
make lower thread tension weak
Make upper thread tension weak or
make lower thread tension strong
①
Weak
Strong
Strong
[ Figure 28 ]
②
Weak
[ Figure 29 ]
21