Adjusting The Needle And Rotary Hook Timing; Adjusting The Hook Stopper Position - Brother LZ2-B850 Service Manual

5-15. Adjusting the needle and rotary hook timing

Index mark Zigzag width
A 8mm
C 5mm
Zigzag width 0mm
r
0-0.05mm
Maximum zigzag width
r
0.2-0.5mm
0604M

5-16. Adjusting the hook stopper position

q
e
w
e
q
Model
B850W, B851
B850
r
y
A
0-0.05mm
r
u
0-0.5mm
q
e
A
w
1. Set the zigzag width to "0", and set the needle posi-
0603M
tion to the center reference line. (Refer to P. 29 – 31.)
2. Remove the presser foot, needle plate, auxiliary needle
plate and feed dog.(Refer to P. 5-06.)
3. Place the auxiliary needle plate q on the needle plate
installation surface of the machine bed.
4. Turn the machine pulley to move the needle bar w from
its lowest position, and check the following when the
distance from the top of the auxiliary needle plate q
to the bottom edge of the needle bar w is the same as
the height of accessory timing gauge 2 e.
• The tip of the rotary hook r should be aligned with
the center of the needle.
• The distance from the tip of the rotary hook r to
the needle should be 0 to 0.05 mm.
Note:
The needle plate and the auxiliary needle plate q are
of different thicknesses, so be sure to use the auxil-
iary needle plate q.
5. If the above are not correct, loosen the two screws t
and adjust the position of the rotary hook y.
After adjustment, securely tighten the two screws t.
6. Set the zigzag width to the maximum setting.
7. Turn the machine pulley to move the needle to its fur-
0605M thest left position so that the tip of the rotary hook r
is aligned with the center of the needle, and check that
the distance from the upper edge of the needle hole to
t
the tip of the rotary hook r is 0.2 to 0.5 mm at this time.
* If the distance is not correct, adjust the height of the
needle bar. (Refer to page 5-06.)
8. If needle deflection occurs when sewing material with
joints, bend the needle guard u in the direction of the
arrow as shown in the illustration A so that it touches
the needle.
* After this, check that the clearance between the tip
of the rotary hook r and the needle is 0 to 0.05 mm.
0606M
Adjust so that the end of the rotary hook holder q is 0 to
0607M
0.5 mm back from end A of the inner rotary hook w.
* The end of the rotary hook holder q must never ex-
tend to the right of end A of the inner rotary hook w.
1. Loosen the screw e and adjust the position of the ro-
tary hook holder q.
2. Securely tighten the screw e.
0608M
LZ2-B850,B851
5. ADJUSTMENTS
• B850.......................5mm
• B850W, B851.........8mm
5-12