JUKI DDL-8000A, Руководство инженера

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Trouble Cause (1) Cause (2) Check and corrective measures
From the previous page From the previous page
1-G) The knife thread guide, moving knife,
or hook has a flaw.
Check whether the hole portion of the hook (especially
the blade top) or knife thread guide has a flaw. If there
is a flaw there, buff the flaw portion sufficiently. If the
flaw portion is large, replace the part.
1-H) The lifting amount of the auto-lifter
device is too large.
Excessive rise of the auto-lifter device causes the
thread guide with presser bar guide to rise rapidly and
the needle thread to be pulled by the thread take-up
spring resulting in shortened needle thread. Readjust
the rise amount of the AK device to approx. 8.5 mm.
Alternatively, set the remaining amount of the needle
thread relatively longer for use of the AK device.
1-2) The R surface treatment
of the edge of a thread
trimming knife (other than
a cutting portion) lacks.
2-A) The thread makes contact with each
other and becomes so short at the
time of trimming thread that it becomes
difficult for the thread to make a knot
at the start of sewing.
The edge of a thread trimming knife (other than a cut-
ting portion) is buff-finished to the extent of R0.5 as an
R surface treatment.
1-3) The low-intensity thread
(such as a high-count fila -
ment type thread or cotton
thread) is being used.
3-A) When the thread trimming speed is
fast, the thread comes to be trimmed
short at the time of trimming the
thread.
The factory-configured thread trimming speed (No. 49 :
210sti/min, No. 50 : 180sti/min) is lowered.
1-4) The bobbin thread is too
short at sewing start.
4-A) Bobbin idling pulls the edge of the
bobbin thread into the bobbin case.
Increase the pressure of the bobbin presser.
Increase the bobbin thread tension.
4-B) The pressure of the bobbin presser is
too high.
Reduce the pressure of the bobbin presser. However,
be careful not to idle the bobbin.
4-C) A flaw on the hook causes the bobbin
thread to be cut too short.
Repair the flaw on the hook, or replace the hook.
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