JUKI AMS-221F3020RSW/AW-3, Instruction Manual

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Trouble Cause Corrective measures Page
3. The needle often
breaks.
① The needle is bent. ○ Replace the bent needle. 18
② The needle strikes the intermediate
presser foot.
○ Correct the position of the intermediate
presser foot.
24
③ The needle is too thin for the
material.
○ Replace it with a thicker needle according
to the material.
④ The position of bird's nest
reducing mechanism is poorly
adjusted. As a result, the moving
knife interferes with the needle.
○ Adjust the position of moving knife before
it trims the thread. (1.1 ± 0.1 mm)
136
4. Threads are not
trimmed.
① The counter knife is dull. ○ Replace the counter knife.
② The difference in level between
the needle hole guide and the
counter knife is not enough.
○ Increase the bend of the counter knife.
③ The moving knife has been
improperly positioned.
○ Correct the position of the moving knife. 136,138
④ The last stitch is skipped. ○ Correct the timing between the needle
and the shuttle.
132
(Bobbin thread
only)
⑤ Bobbin thread tension is too low. ○ In crease the bobbin thread tension. 23
⑥ Flopping of cloth ○ Lower the intermediate presser height of
the last stitch.
5. Stitch skipping
often occurs.
① Timing between the needle and
the hook is not correct. The
clearance provided between the
needle and the hook is too large.
○ Correct the positions of the needle and
shuttle.
132
② The needle is bent. ○ Replace the bent needle. 18
③ Length of needle thread remaining
after thread trimming is too long.
(In the case of stitch skipping
within the 2nd to 10th stitch from
the beginning of sewing)
○ Reduce the thread take-up spring
pressure or increase the thread tension
applied by the thread tension controller
No. 1.
23,24
6. The needle thread
comes out on the
wrong side of the
material.
(Poorly tensed
seam)
① The needle thread tension is not
high enough.
○ Increase the needle thread tension. 23
② The tension release mechanism
fails to work properly.
○ Check whether or not the tension disc No.
2 is released during bar-tracking.
③ The needle thread after thread
trimming is too long.
○ Increase the tension of the thread tension
controller No. 1.
○ Decrease the tension of thread take-up
spring.
23
24
④
Number of stitches is too few. ○ Turn OFF the thread clamp. 26
⑤ The material is separated from
the throat plate. As a result, the
material sways and the thread is
pulled up.
○ Use the concave type feed plate that
allows the material to come in close
contact with the throat plate.
○ Decrease the stroke of the intermediate
presser.
136
⑥ Thread slips off the tension
controller.
○ Increase the thread tension of the tension
controller No. 1.
23
7. Thread end of
the 1st stitch
comes out on the
right side of the
material.
① Stitch skipping at the 1st stitch ○ Adjust the hook timing faster by a 1/2
stitch.
132
②
Needle used and thread used
are thick in terms of the inner
diameter of the intermediate
presser.
○ Increase the inner diameter of
intermediate presser.
157
③ Intermediate presser is not
properly positioned in terms of the
needle.
○ Adjust the eccentricity between
intermediate presser and needle so
that needle enters in the center of
intermediate presser.
132