Brother DB2-DD7100, Service Manual

Page: 76 / 153

7. ADJUSTMENTS
SL-710A
69
7-9. Quick reverse mechanism
1. Turn the stitch length dial to the maximum setting.
2. Remove the rear cover.
3. Tilt back the machine head.
4. Check that the position of the solenoid lever screw (1)
can be verified when the machine head is restored to
its normal position.
* If the automatic presser lifter has been installed,
remove it. (Refer to page 17.)
5. Return the machine head to its normal position, and
loosen the screw (1).
6. Check that the plunger pin (2) is in the groove (A) in
the solenoid lever.
7. With the reverse stitching lever (3) lowered all the way,
push the plunger (6) until the clearance between the
setting plate (5) of the quick reverse solenoid (4) and
the plunger (6) is 0.5 - 0.7 mm.
8. Tighten the screw (1).
* If the above clearance of 0.5 - 0.7 mm is large, the
operation of the quick reverse solenoid (4) will
become slower.
In addition, if the clearance is small, the impact
noise from the quick reverse solenoid (4) will
become more apparent.
7-10. Matching stitch lengths for normal feed and reverse feed
The following operation matches the stitch lengths for
normal feed and reverse feed.
1. Turn the stitch length dial to the "3" setting.
2. At a low sewing speed (220 rpm), sew using normal
feed and using reverse feed (11 stitches in each
direction)
3. If adjustment is required, carry out the following.
1) Tilt back the machine head.
* If the automatic presser lifter has been installed,
remove it. (Refer to page 17.)
2) Loosen the screw (1).
3) Adjust by turning the eccentric pin (2) within a range
of 90
°
. (If the eccentric pin (2) is turned more than
90
°
, the adjustment will be reversed.)
• If the stitch length is larger for normal feed
than for reverse feed
Turn the eccentric pin (2) clockwise.
• If the stitch length is smaller for normal feed
than for reverse feed
Turn the eccentric pin (2) counterclockwise.
4) After adjusting, securely tighten the screw (1).
1789M
1790M
(1)
(6)
(5)
(2)
(A)
(3)
(4)
(1)
0.5 - 0.7 mm
Push
1822M
1823M
(1)
(2)
(2)
Normal feed
11 stitches
Reverse feed
Normal feed length becomes
smaller
Normal feed length
becomes longer