Adjusting The Thread Trimming Timing - Brother S-710A Service Manual

6. ASSEMBLY

6-15-4. Adjusting the thread trimming timing

Needle bar lowest position
Reference line (a)
DA X 1 DB X 1
DP X 5
(4)
(C)
Cam rotating direction
(5)
(2)
[A]
0.6 - 0.8 mm
(4)
1mm
47
Raised 5 mm
Reference line (b)
DA X 1 DB X 1
DP X 5
(1)
(3)
0.5 mm
(4)
(2)
(2)
(3)
(2)
(6)
1mm
(5)
(10)
(6)
(5)
(10)
(7)
(8)
(9)
Marks
Remove the fed dog.
Thread trimmer cam position adjustment
1. Turn the pulley to raise the needle bar 5 mm from its
lowest position (reference line (a) position) so that
reference line (b) is aligned with the bottom of the
needle bar bush.
1770M
2. From the above position, push the thread trimmer
solenoid (1) with a finger in the direction of the arrow.
At this time, adjust the position of the thread trimmer
cam (2) so that the roller shaft (4) of the thread trimmer
cam lever assembly (3) touches the hollow (c) in the
thread trimmer cam (2), and so that the clearance
between the surface of the thread trimmer cam (2) and
the roller shaft (4) is 0.6--0.8 mm. Then tighten the set
screw (5). (Figure (A))
[B]
3. Check that the clearance between the surface of the
thread trimmer cam (2) and the roller shaft (4) is 0.5
mm when the roller shaft (4) returns to the right.
(Figure (B))
(4)
* Tighten the set screw (5) at a torque of
1771M
approximately 4 N.m.
Movable knife and fixed knife position adjustment
1772M
1. Turn the pulley and push the thread trimmer solenoid
(1) with a finger.
2. While doing this, turn the pulley again until the roller
shaft (4) of the thread trimmer cam lever assembly (3)
is sitting on top of the thread trimmer cam (2). In this
1773M
position, move the thread trimmer lever (7) to adjust so
(6)
that the amount of overlap between the tip of the fixed
knife (5) and the edge of the movable knife (6) is 1 mm.
Then tighten the screw (8).
(5)
* At this time, adjust so that the meshing amount is 1
mm, using the alignment of the marks on the thread
trimmer holder and the bush as a guide.
* Tighten the screw (8) so that there is no play in the
forked shaft (9).
* The lower thread finger (10) must be below the
movable knife (6).
1774M
SL-710A