JUKI MO-6000G Series Engineer's Manual page 85

Trouble Case (1}
From the previous page
9. Triangle double chain looper thread stitches
are skipped.
The needle falls to catch the double chain
looper Ulreed.
Needle Viewed from the
wrong side
One stitch le ekfpped.
AdJustment of looper
Thread tension
Needle guards
Needle heat
The needle poinl Is crushed.
Double chain looper
Adjustment
ol
looper
Thread cam timing
Thread tension
Threading
Case(2)
Clearance or returning amount is not correct.
The thread tension is too high, preventing formation of
good loops.
A
needle
guard is
too high, and loops are crushed. The
clearance is too big, causing the needle to shake.
The thread breaks due to heat generated on the needle,
depending on the type of materials, number of plies,
and sewing speed.
The needle point has been crushed and got thicker and
shoner.
The thread hole In the tip has worn, and the looper
thread does not reach the needle as shown at right.
Excessive rerum or longitudinal motion will often cause
this stilch skipping.
Tho thread cam timing is too early, causing the looper
thread to slack before the needle enters a thread
triangle.
The lower thread tension Is very low, and the thread is
not stretched.
The area around the thread cam has threaded
erroneously.
Check and Corrective measures
Refer to the related Standard Adjustment.
Reduce the tension. However, be careful not to reduce
the tension too much, othrewlse unstable loops
wm
result.
Reier to the relevant Standard Adjustment.
Use a thinner needle. Reduce the sewing speed. Check
the coolant if necessary.
Refer to tho clause relating
to
the needle point
crush.
Replace tho double chain looper.
Reier to tho pertinent Standard Adjustment.
Reier to the pertinent Standard Adjuslmll!nt.
Increase the thread lenslon a little.
Correct the threading.
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