Table of Contents
Advertisement
Trouble
① The motions of the needle
5. Stitch skipping
often occurs.
② The clearance between the
③ The needle is bent.
④ The driver excessively bends the
⑤ Length of needle thread
① The needle thread tension is not
6. The needle
thread comes
② The tension release mechanism
out on the wrong
side of the
material.
③ The needle thread after thread
④ Number of stitches is too few.
⑤ When sewing length is short (End
⑥ Number of stitches is too few.
① Stitch skipping at the 1st stitch
7. Thread end of
the 1st stitch
comes out on
② Needle used and thread used
the right side of
the material.
③ Intermediate presser is not
① The moving knife has been
8. Threads break
at time of thread
trimming.
① The needle thread at the sewing
9. The thread
clamp is
entangled with
needle thread.
① The tension of thread take-up
10. Uneven length
of the needle
thread
① The tension of thread tension
11. The length of
needle thread
does not
② The tension of thread take-up
become short.
③ The tension of thread take-up
① Idling of bobbin is large.
12. The knotting
section of
② The bobbin thread tension is too
bobbin thread
at 2nd stitch at
③ The needle thread tension at 1st
the sewing start
appears on the
right side.
① Needle entry of the last needle
13. Wiper fails to
work. (Return is
defective.)
Cause
and shuttle are not properly
synchronized.
needle and shuttle is too large.
needle.
remaining after thread trimming
is too long. (In the case of stitch
skipping within the 2nd to 10th
stitch from the beginning of
sewing)
high enough.
fails to work properly.
trimming is too long.
of needle thread protrudes on the
wrong side of sewing product.)
are thick in terms of the inner
diameter of the intermediate
presser.
properly positioned in terms of
the needle.
improperly position.
start is too long.
spring is too low.
controller No. 1 is too low.
spring is too high.
spring is too low and motion is
unstable.
low.
stitch is too high.
is the same as that of the sewing
start, and the resistance of
thread and cloth is large.
Corrective measures
◦ Correct the positions of the needle and
shuttle.
◦ Correct the positions of the needle and
shuttle.
◦ Replace the bent needle.
◦ Correctly position the driver.
◦ Reduce the thread take-up spring
pressure or increase the thread
tension applied by the thread tension
controller No. 1.
◦ Increase the needle thread tension.
◦ Check whether or not the tension disc
No. 2 is released during bar-tracking.
◦ Increase the tension of the thread
tension controller No. 1.
◦ Correct the position of the moving knife.
◦ Turn OFF the thread clamp.
◦ Turn OFF the thread clamp.
◦ Use the lower plate, the hole of which
is larger than the presser.
◦ Adjust the hook timing faster by a 1/2
stitch.
◦ Increase the inner diameter of
intermediate presser.
◦ Adjust the eccentricity between
intermediate presser and needle so
that needle enters in the center of
intermediate presser.
◦ Correct the position of the moving
knife.
◦ Tighten thread tension controller No. 1
and make the length of needle thread
40 to 50 mm.
◦ Increase the tension of the thread
take-up spring.
◦ Increase the tension of thread tension
controller No. 1.
◦ Decrease the tension of thread take-
up spring.
◦ Increase the tension of thread take-
up spring and lengthen the stroke as
well.
◦ A just the position of the moving knife.
◦ Increase the bobbin thread tension.
◦ Decrease the needle thread tension at
1st stitch.
◦ Turn OFF the thread clamp.
◦ Shift the needle entry point of the last
needle.
– 129 –
Page
116
116
19
116
22, 23
22
22
119
26
23
22
23
119
22
Advertisement
Table of Contents
