JUKI IT-100D - Page 121

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Needle
thread
clamp
failure
Bobbin
thread at
the start of
sewing is
drawn up on
the cloth.
Knife to cut
needle thread
is dull.
Interference
of wiper with
needle
Phenomenon
Bird’s nest prevention (CB) type
1
Improper wiper position.
2
Air pressure drop.
3
Dust bag becomes excessively lled with
waste thread.
4
Thread trimmer or wiper operates when
needle does not enter the cloth.
5
Needle thread length is too short.
Thread does not reach the clamp head.
6
Uneven length of left and right needle
threads
(Thread which is not stretched such as
cotton thread or the like is used.)
Adjust the wiper to the proper position.
Set the air pressure to 0.6Mpa.
Remove waste thread from the dust bag.
Operate thread trimmer or wiper on the
cloth.
Perform pre-tension adjustment and lengthen
needle thread. (Adjust the length from the
clamp head to approximately 20 to 35 mm.)
See page
Cause
Corrective measure
Step 1 :
Increase the drawing amount of needle
thread and increase needle thread
remaining amount at the start of sewing.
Step 2 :
Make tension release SOL (solenoid)
actuate at the start of sewing to perform
tension release and increase the thread
remaining amount.
(Input the number of stitches of thread release at
the start of sewing with function setting No.100.)
Step 3 :
Make the thread drawing device actuate
again after completion of needle thread
clamp to perform tension release and
increase the thread remaining amount.
(Set function setting No.18 to 2.)
Step 4 :
Make all step items (1 + 2 + 3) function.
Replace the knife with a new one.
Adjust the position to the proper one.
Adjust the UP stop position.
Re-adjust the locus of the wiper.
Re-adjust the position of the wiper.
Bobbin thread is taken up on the cloth by
needle thread at 1st stitch at the start of sewing
since needle thread remaining amount after
completion of needle thread clamp is small.
20 to 35 mm
Needle thread
Clamp head
Change the kind of thread.
1
Worn-out of needle thread cutting knife.
2
Improper installing position of the knife.
1
Improper UP stop position.
2
Improper wiper locus.
3
Improper wiper position.