12
BAS-761
5-5. Thread tension
w
qr
e
Stitches when upper
thread tension is too low
Stitches when upper
thread tension is too high
Correct stitches
1. When the thread take-up lever is in the highest position after thread trimming, adjust the upper thread beyond the
needle eye so as it is 30 to 40 mm long, by turning tension nut q. (30 - 70 g is standard).
2. Adjust the lower thread tension by turning tension regulating screw w. (40 - 60 g is standard.)
3. Adjust the upper thread tension by turning tension nut e and r after lowering the presser foot.
Note:
Then adjust the tension 30 - 40 g by turning tension nut r.
Main adjust is performed by using tension nut e.
x2.4 rotary hook 150 - 200 g is standard.
x1.7 rotary hook 200 - 220 g is standard.
■ Thread take-up spring
1. The standard height of the thread take-up spring q is when the stroke is 5 to 8 mm.In addition, the standard tension
in the thread take-up spring is 30 g to 60 g (x1.7 rotary hook 40 - 80g).
(The tension in the thread take-up spring when it is pulling the upper thread straight to the side at the point where
the spring starts to move.)
2. To adjust the thread take-up spring height, loosen set-screw w and turn the whole unit of the tension regulator
assembly.
3. To adjust the thread take-up spring force, insert a screwdriver tip into the groove of tension stud e and turn it as
much as is appropriate.
Low
High
w
e
qq
30 - 60g
5 - 8mm
5. Correct operation
■ x2.4 rotary hook ■ x1.7 rotary hook
w
Low
High
e
■ x2.4 rotary hook
■ x1.7 rotary hook
()■ x2.4 rotary hook
■ x1.7 rotary hook
e
40 - 80g