Adjusting The Needle Up Stop Position; Adjusting The V-Belt Tension - Brother HE-800A Service Manual

4-24. Adjusting the needle up stop position

4-25. Adjusting the V-belt tension

The needle up stop position is adjusted so that the
index mark (2) on the machine pulley (1) is inside
the mark (4) on the belt cover (3).
If adjustment is necessary, loosen the screw (5) of
the machine pulley (1). The machine pulley (1) will
stop more slowly if the screw (5) is moved counter to
the normal direction of rotation, and will stop more
quickly if the screw (5) is moved in the normal
direction of rotation.
Note:
The screw (6) at the "D" mark is an adjusting
screw for the needle down detection function and
is adjusted to match the feed timing, so it should
not be loosened.
* If the index mark (2) is not inside the mark (4)
when the sewing machine is started, and error
code "E-02" will be displayed. Turn the machine
pulley to move the index mark (2) to the correct
3990Q
position and then start the sewing machine.
1. Remove the three screws, and then remove the
belt cover.
2. Turn the two nuts (2) to adjust so that there is 10 -
14 mm of deflection in the V-belt (1) when it is
pressed at the midway point with a force of 5 N.
Note:
If the V-belt tension is too loose, or if the V-belt is
stretched, the following problems could occur.
a. The stopping position may shift,
b. The needle bar may drift when the machine
stops,
c. An extra stitch may be sewing when the
machine stops,
d. An abnormal noise may be heard due to V-belt
slipping, and
e. The V-belt may become too loose and contact
with the cover.
If any such problems occur, adjust by following the
4367Q
procedure described above.
HE-800A
4. ADJUSTMENT
103