JUKI MO-6000G Series Engineer's Manual page 84

I
......
~
I
Trouble
7.
Upper looer thread stitches are skipped.
The needle does not take the upper looper
thread.
Lower looper
thread
-~
Upper looper
Right side Wrong side
a.
Double chain slitches are skipped.
The double chain looper tails to catch needle
thread Joopa.
Needle
Viewed from the
/
Two stitches
are skipped.
Case
(1)
Threading
Needle height
Needle
Adjustment of the upper looper.
Amount of thread
Needle height
Needle
Double chain looper
to the next page
Case(2)
The thread has been entangled wllh a thread guide.
Threading has not been done correctly.
The needle, If positioned too high or low,
may
fail to
catch the upper looper thread.
The needle Is bani or crushed, in Its point.
The height of lhe blade point Is not correct,
making
the
upper looper unable to properly pass the thread to the
needle.
The clearance between the needle and the back of the
upper looper is not correct.
Excess!ve upper looper thread Is fed, producing slack
of thread.
Need!:
k::?'"
Slack of thread
II the needle is not correct, slHch skipping occurs even
when the return or the chain looper Is correct.
The needle is bent or attached wllh wrong orientation.
' A DC x1 needle is used.
The lower part of the blade point has been deformed,
and the blade point fells loops.
Check and Corrective measures
See the threading diagram.
Refer lo lhe related Standard Adjustment
Replace the needle. At this time, be sure
to
eliminate the
cause for such needle bend or needle point crush.
Refer to
the
relevant Standard Adjustment.
Sllghtly lower the looper thread take-up (left) (reduction
In distance J), or sllghtly reduce distance I to decrease
the amount of thread.
Make the uppor looper thread guide {right) (shprter
decrease in distance K). to reduce the amount or thread.
Slightly raise the looper thread take-up (right) (increase
In dimension
O)
to decrease the amount of thread .
If
the thread tension
is
not
enough, Increase it.
Refer to the pertinent Standard Adjustment.
Replace the bent needle. (Remove the cause for the
needle bend.) Correct the orientation of the needle. Use
a DC x27 needle (with a better recess configuration).
Replace the double chain looper.
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