LK3-B438E Mark II
13
r
Approx. 9-10mm
10N
V-belt
Motor
A
B
3-14 . Installing the V-belt
Approx.
1mm
Sewing
machine
1. Gently tilt back the machine head, and then place
the V-belt
q
into the V grooves on the machine
head pulley
w
and the motor pulley
e
.
NOTE:
After tilting back the machine head, do not push the
face plate side or the pulley side from above.
2. Gently return the machine head to its original po-
sition.
* Be careful not to clamp the cords at this time.
3. Provisionally install the accessory tension pulley
assembly
r
with the accessory flat washer, spring
washer and bolt.
4. Adjust the belt tension by moving the tension pul-
ley assembly to the right and left so that there is 9-
-10 mm of deflection in the V-belt
q
when it is
gently pushed in the middle with a force of ap-
proximately 10 N. After adjusting, tighten the bolt
A
to secure the left pulley assembly.
5. Move the right tension pulley so that there is a
gap of about 1 mm between it and the V-belt
q
,
and then tighten the bolt
B
to secure the right
pulley assembly.
NOTE:
Use brother specified V-belt (belt, VM).
The V-belt
q
may stretch slightly when it is first used,
so adjust the belt tension after about 3,000 cycles of
use.
When above belt tension is week, this will be cause of
following problems;
• Noise & vibration become large.
• Needle up stop position becomes unstable.
• Error message [E-50] is displayed.
Check that the motor is positioned so that the V-
belt is straight. (Fig.1)
3. INSTALLATION
w
q
e
Fig.1
