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(2) Adjusting the bobbin thread tension
1) Turning tension controller
❶
clockwise (in direction
A
) will increase the bobbin thread tension.
2) Turning the tension controller counterclockwise (in
direction
B
) will decrease the bobbin thread ten-
sion.
❶
A
B
(1) Adjusting the stroke of thread take-up spring
1) The standard stroke of the thread take-up spring is
6 to 11 mm.
2) To change the stroke of thread take-up spring
❶
,
Ioosen screw
❷
in the tension post socket, fit a flat-
bit screwdriver in the groove in tension post
❸
and
turn the post with the screwdriver. Turning the post
clockwise (in direction
A
) will increase the stroke.
Turning it counterclockwise (in direction
B
) will de-
crease it.
(2) Adjusting the pressure of thread take-up
spring
1) The pressure of the thread take-up spring should
be adjusted to 0.15 to 0.25N when it starts pulling
the thread.
2) Fit a flat-bit screwdriver in the groove in tension
post
❸
, and turn the tension post clockwise (in di-
rection
A
) to increase the pressure of thread take-
up spring, or counterclockwise (in direction
B
) to
decrease it.
4-7. Thread take-up spring
1. When adjusting the stroke of thread take-up spring, the position of the thread breakage de-
tecting plate should also be adjusted. Adjust the position of the thread breakage detecting
plate so that it always comes in contact with the thread take-up spring when the thread take-
up spring is not threaded. (Deflection of the spring is approximately 0.5 mm)
* Do not adjust the stroke of thread take-up spring using the thread breakage detecting plate.
Doing so may result in thread take-up spring breakage.
2. Confirm that the tension disc comes in close contact with the thread take-up spring after the
stroke of thread take-up spring after the stroke of thread take-up spring has been adjusted.
If the tension disc does not come in close contact with the thread take-up spring, Ioosen
sorew
❷
in the tension post socket, and draw the tension post in direction
C
to make the
adjustment.
❶
❷
❸
A
B
C
