JUKI MO-6700D Series Manual page 33

Adjustment Procedure
1) When the knives have become dull, fully resharpen lower knife
until the contact mark of it disappears.
2) When the upper knife has become dull, replace it with a new one.
(This is because the upper knife is a serrated carbide knife.)
Adjustment Procedure
1
1) Adjusting the thread cam
Adjust the position of the thread cam by its setscrew
needles at their upper dead point so that the straight section of the
2
thread cam is leveled.
Laterally position the thread cam so that the looper thread cam nail is
located at the center of the thread cam groove.
[How to check for proper positioning]
Check that the thread cam releases the looper thread when the needle
tip begins to come out of the bottom surface of the throat plate by 0 to 1
mm.
Thread
2) Adjusting the looper thread cam thread guides A and B and the
1
looper thread cam nail
Install looper thread cam thread guides A
2
the slots with setscrews A
Install looper thread cam nail
section of the forked portion is leveled.
Throat plate
and B
and B .
with setscrew so that the straight
– 29 –
Results of Improper Adjustment
o If the 10∞ angle of the lower knife
is exceeded, the durability of the
knife will be deteriorated, often
resulting in blade chipping.
o If the angle is smaller than 10°,
the knife will be dull.
o If the 55° angle is not observed,
the knife may catch materials.
Results of Improper Adjustment
o If the timing of the thread cam is
with the too early, the needle point will fail
to enter a thread triangle,
resulting in looper thread stitch
skipping.
o If the timing of the thread cam is
too late, puckering and loose
looper thread stitches will results.
0 to 1 mm
o If the chain looper thread guide
is moved away from you, the
take-up amount of the lower
at the center of
looper thread will decrease. In
this case, puckering may result
there by impairing the feeling of
the finished product.