28
Tension release claw
Setscrew
1.5 mm thick plate
Tension discs supporter
Tension discs supporter
1.2 – 1.8 mm
Thread tension release
adjusting plate
Mechanical Adjustment
Tension release mechanism
The tension disk should open when the presser foot is raised and the tension disk should close when the presser foot is lowered.
To check:
1 Remove the belt cover and top cover (see pages 1 and 2).
2. Remove the front cover (see page 5).
NOTE: Do not disconnect connectors from the printed
circuit board A.
3. Turn the power switch ON and the presser foot is raised
automatically. The projection of the thread tension gear is
set at the tension release claw and the tension disk should
open.
4. Press the presser foot lifter button to lower the presser foot.
The thread tension gear turns and the projection goes off
the tension release claw. The tension disk should close.
If the tension release does not work properly, adjust the
clearance between the tension release adjusting plate and
tension disk supporter.
To adjust:
1. Lower the presser foot. Loosen the setscrew and insert a
1.5 mm thick plate between the tension release adjusting
plate and the tension disc supporter.
2. Tighten the setscrew while pushing the tension release
claw against the thread tension gear.
3. Remove the 1.5 mm thick plate. The clearance between
the tension release adjusting plate and the tension disc
supporter should be 1.2 mm to 1.8 mm.
4. Raise the presser foot and check if the tension disk opens.
Tension release claw
Projection
Thread tension gear
Tension release claw
Projection
Tension disk opens
Tension disk closes
Thread tension release
adjusting plate
Tension disk opens