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Adjustment procedures
Results of Improper adjustment
1. Loosen the clamping screw
❸
of the upper looper ball arm and
the clamping screw
❺
of the upper looper holder.
2. Adjust the clearance between the upper looper bracket
❹
and
the upper looper holder
❶
to approximately 0.1 mm respective-
ly, and tighten the clamping screw
❺
of the upper looper holder.
(Make sure that the upper looper holder smoothly moves together
with upper looper shaft
❻
.)
3. Then determine dimension
H
from the bottom surface
A
of the
frame to the top surface of upper looper holder pin
❷
before
tightening the clamping screw
❸
of the upper looper ball arm.
* Refer to "4-(19) Positioning the upper looper lubricating pin" for
the upper looper holder pin.
o
Inaccurately positioned upper
looper holder will cause exces-
sive projecting amount of the
upper looper, resulting in stitch
skipping, or other troubles.
(Caution) To adjust the upper
looper ball arm, take
dimension H as stan-
dard. Remember that
the projecting amount
and the height of the
upper looper should
eventually be properly
adjusted. So, confirm
the dimensions related
to the upper looper.
