typical GC6-7 - 5.1 Adjusting the Thread Take-up Spring

24
B
C
A
23
11
22
A
B
It is a common practice to check the bobbin
thread tension as shown in Fig. 22. In case of glazed
thread #50, hold the end of pulled out thread and to
vibrate bobbin case up and down, if the bobbin case
fall down slowly, the proper tension is obtained.
The needle thread tension can be adjusted by
changing:
(1) tension of the thread take-up spring,
(2) swinging range of the thread take-up spring,
(3) tension of tension disc
(4) the position of thread guide 6 in fig. 17. All
these adjustments will be described as follows.
Bobbin
5.1. Adjusting the thread take-up spring
The normal tension of thread take-up spring is approx.
35-55. The normal swing range of the thread take - up
spring is 5-8mm. For sewing light weight materials (with
short stitch length), weaken the spring tension and widen
the swinging range of spring, while for sewing heavy
weight materials, strengthen the spring tension and
shorten the swinging range of spring.
5.1.1 Adjusting the thread take-up spring tension(Fig.23)
Loosen tension stud set screw A, turn tension stud B
clockwise to increase the spring tension, or turn the
tension stud counter-clockwise to decrease the spring
tension. After the adjustment, be sure to tighten tension
stud set screw A.
The thread take-up spring tension is about 45g. To
attain this, loosen set screw A first, then turn tension stud
B counter clockwise to release the tension of thread take-
up spring C to zero, and turn tension stud B
clockwise until spring C just comes into contact with the
stopper on thread take-up spring regulator, then further
turn tension stud B clockwise be 1/2 turn. After adjustme
-nt, tighten tension stud set screw A.
5.1.2 Adjusting the swing range of thread take-up
spring (Fig.24)
Loosen set screw B, turn tension complete C
clockwise to increase the swing range or turn tension
complete C counter-clockwise to decrease the swing
range. After the adjustment, tighten set screw B.
Before delivery, thread take-up spring is properly
adjusted. Re-adjustment is needed only in the case of
sewing special material material or with special thread.
B
C
5
~
8
mm