Adjusting The Synchronizer - Brother LZ2-B855E Service Manual

6-13. Adjusting the synchronizer

• The synchronizer consists of two elements which are used to detect the needle position. One of these elements is
used to control the needle down signal and the thread trimmer signal.
• When the power is turned on and the sewing machine stops in the needle up stop position, the reference line on the
thread take-up lever should stop near the U mark on the face plate (± 3 mm).
Furthermore, when the sewing machine stops in the needle down stop position, the reference line on the thread
take-up lever should stop near the D mark on the face plate (± 4 mm).
<Needle up stop position adjustment>
1. Turn off the power switch.
2. Loosen the two set screws q.
3. Move set screw q in the direction of normal puley rotation to raise the needle bar. Move the screw q in the opposite
direction to lower the needle bar.
4. Tighten the set screws q.
<Needle down and thread trimmer signals>
Do not adjust the needle down stop position.
* Note
• The synchronizer is preadjusted at the factory. Do not remove the synchronizer after removing the pulley.
• When mounting the pulley be sure to leave a 0.5 mm gap between the pulley edge and synchronizer.
Furthermore, tighten the two machine pulley set screws so that the rear set screw is at the screw stop on the upper
shaft when seen from the machine pulley turning direction.
1021S
Needle up stop
U
D
1024S
1022S
Needle down stop
1025S
LZ2-B855E,B856E
6. ADJUSTMENTS
1023S
Direction of machine
pulley rotation
q
0.5mm
1026S
6-10