JUKI LU-2810 Series, Engineer'S Manual

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WARNING :
Turn �FF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine.
Trouble Cause Checking Corrective measures
1. One or several stitch-
es skip at the start of
sewing.
1-1) Thread remaining at the needle top
after thread trimming is short.
1-A) Check the routing of needle thread. Thread the needle thread correctly.
Adjust so that abnormal needle thread tension is not
applied.
1-B) Thread tension given by the tension con-
troller No.1 is too high.
Decrease the tension given by the tension controller
No.1.
1-C) Check the rising amount of the thread
tension disk No.2 at the time of thread
trimming.
Adjust so that the disk is raised by means of the
thread release solenoid.
1-D) Thread trimmer timing is excessively
advanced.
Refer to “2.-(17)-6) Thread trimmer cam timing”.
1-E) There are scratches on the moving knife
and the hook.
Polish with buff or replace the part with a new one.
1-F) Presser foot drops from cloth at the time
of thread trimming.
Perform thread trimming on cloth.
1-2) Bobbin thread is not clamped. 2-A) Position of the clamp spring. Refer to “2.-(17)-1) Position of the counter knife and
the clamp spring”.
2-B) Pressure of the clamp spring is too low. Refer to “2.-(17)-1) Position of the counter knife and
the clamp spring”.
2-C) There are scratches on the clamp spring. Replace the clamp spring with a new one.
2-D) Needle thread removes bobbin thread.
Increase or decrease the tension of the tension con-
troller No.1.
1-3) Needle is too thick. Replace the needle with a thinner one.
1-4) Needle hole in the feed dog is too large. Replace the feed dog with small needle hole.
1-5) Pressure of the presser foot is too low. Increase the pressure of the presser foot.
1-6) Stitches are too small. Do not pass thread through the thread presser sec-
tion of the thread guide on the needle bar.
(2) With regard to thread trimming
海外講習会用121122 LU-2810(-7)̲EM