JUKI MO-6800S Series Engineer's Manual page 21

Adjustment procedures
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.
Results of Improper adjustment
Inaccurately positioned upper
o
looper holder will cause exces-
sive projecting amount of the
upper looper, resulting in stitch
skipping, or other troubles.
(Caution) To adjust the upper
– 9 –
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.