9. ADJUSTMENTS

9-22. Adjusting the tension of the plate spring (8560A only)

Becomes weaker

3539M

3540M

Nylon thread

Becomes stronger

Adjust the tension of the plate spring (1) so that the tension is 0.03 to 0.11 N when the plate spring (1) is pulling the lower thread (nylon thread: 100D 1 X 3 (Z)) after thread trimming.

1.Remove the knife unit (2). (Refer to “11-1. Fixed knife and movable knife (8560A only)” of the Instruction Manual.)

2.Move the knob (3) to slide out the movable knife (4), and then hook the thread as shown in the illustration.

3.Return the movable knife (4) to trim the thread. After this, measure the tension of the lower thread presser spring

(1)while it is pulling the lower thread.

4.Turn the screw (5) to adjust the tension of the plate spring

(1)to 0.03 to 0.11 N.

NOTE: If using a tension gauge (sold separately) to measure the tension, take the reading from the scale on the side of the red line.

3541M

9-23. Adjusting the thread trailing length after thread trimming (8560A only)

3810M <Standard position for upper thread feeding device>

The standard position for the upper thread feeding device is as shown in the illustration.

1. Loosen the set screw (1).

2. Turn the base (2) so that the end of the wire (3) is at a position 3 mm below the position where the upper thread

(4) passes.

3. Tighten the set screw (1).

* At this time, keep the end of the wire (3) 1 mm away from surface (A) of the thread guide (5).

4. Loosen the two bolts (6).

5. Move the wire (3) to the left or right so that the end of the wire (3) is 10 mm from the top-left edge of the thread guide (5).

6. Tighten the bolts (6).

Seen from direction (B)

83

Z-8550A, 8560A