JUKI LK-1900AN Engineer's Manual page 55

Adjustment procedures
1. Remove the feed bracket, feed plate, and the needle plate.
Make adjustments with the screw 1 .
(Caution) The right and left positions can also change during
"(11) Hook adjustment." Position adjustment for the
shuttle upper spring 2 should be done after the
completion of standard hook adjustment, without
fail.
Adjustment procedures
1. If the shuttle felt 1 seems to be protruded or it has been re-
placed with a new one, push it in by means of tweezers or the
like.
(Caution) Do not push it in excessively. Align the height and
the plane of the shuttle race 2 .
Results of Improper adjustment
If there is a front and rear dis-
o
placement or a right and left
displacement, needle thread bit-
ing may occur into the hook. Too
much motion to the rear side will
cause the moving knife to fail to
hook the needle thread.
Too much motion to the rear side
o
will cause the moving knife to fail
to hook the needle thread.
Too much motion to the left side
o
will cause the moving knife to fail
to hook the bobbin thread.
Results of Improper adjustment
If the shuttle felt 1 is protruded,
o
this will be turned into a rotary
load of the inner hook, causing a
sewing error.
If the shuttle felt 1 is missing
o
or pushed in too much, this will
result in hook lubrication defi-
ciency, causing hook overheat-
ing and wear.
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