9. ADJUSTMENTS

Should not touch

Longer

Shorter

Stronger

Weaker

3811M <Adjusting the upper thread trailing amount>

The standard trailing length for the upper thread is 50-60 mm.

If adjustment is necessary, adjust the position of the wire e as described below.

1.Loosen the set screw (1).

2.Turn the base (2) to adjust the vertical position of the end of the wire (3).

To increase the upper thread trailing amount, raise the position of the wire (3) without letting it touch the upper thread (4).

To decrease the upper thread trailing amount, lower the position of the wire (3) without letting it touch the thread guide (5).

3.After adjusting, 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).

Seen from direction (B)

NOTE:

If the tension of the pre-tension (6) is too strong, it will be more difficult to adjust the upper thread trailing amount.

The pre-tension (6) should be adjusted to as weak a tension as possible while still allowing the rotary disc (7) to rotate smoothly.

*The thread tension will change at this time, so be sure to re-adjust the upper thread tension. (Refer to “9-1. Adjusting the thread tension” of the Instruction Manual.)

9-24. Adjusting the thread wiper (8560A only, optional device)

<When seen from the rear> <When seen from the front> <Horizontal position adjustment>

The front corner of the thread wiper (2) should be positioned 9 mm away from the left edge of the needle hole of the presser foot (3) (or the needle hole of the needle plate (4)) when the solenoid plunger (1) is pushed up as far as it will go.

Loosen the two screws (5) and move the setting plate (6) up or down to adjust.

<Height adjustment>

Adjust so that the distance from the bottom edge of the thread wiper (2) to the top of the needle plate (4) is 5 mm.

Loosen the screw (7) and move the thread wiper (2) up or down to adjust.

<Forward/back adjustment>

Adjust so that the edge of the thread wiper (2) is positioned 1 mm forward of the needle tip (8).

Loosen the screw (7), and then turn the thread wiper (2) to adjust.

3812M

Z-8550A, 8560A

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