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10. Flaw on the bobbin
10-1) The bent needle scratches the
Use a hook with needle holder that is compatible with #11
bobbin.
or equivalent needles. 11141355 for SS, 22890404 for DS
11. Irregular stitch
11-1) The matters related to the hook
1-A) Hook oil is too large or too
Adjust the oil volume to the appropriate level.
are inappropriate.
small in amount.
1-B) The hook is defective. (thread
Replace the hook or modify the thread path.
catch, defective thread path, etc.)
11-2) The bobbin or bobbin case is
2-A) Inappropriate engagement
Replace the bobbin or bobbin case.
defective.
between the bobbin and bobbin
case causes the bobbin thread
to be caught.
2-B) Defective thread winding around
Adjust the tension and position of the bobbin thread.
the bobbin winder causes the
Also be aware of uneven winding.
bobbin thread to be caught.
2-C) The tension adjusting spring of
Replace the bobbin case.
the bobbin case is defective.
2-D) The bobbin thread idles in the
Adjust the tension of the idling prevention spring with
bobbin case.
reference to 3.-(5).
2-E) The bobbin is inserted into the
Refer to 3.-(5). Irregular stitches are corrected by rotating
bobbin case in the wrong direction.
the bobbin in the reverse direction.
11-3) The needle or bobbin thread
Increase the tension of the needle or bobbin thread.
tension is too low.
11-4) The thread take-up spring is
4-A) The stroke of the thread take-up
Adjust the stroke of the thread take-up spring.
inappropriately adjusted.
spring is too long or too short.
4-B) The tension of the thread take-
Adjust the tension of the thread take-up spring.
up spring is too high or too low.
11-5) The thread path is defective.
5-A) The thread path is not smooth.
Finish the thread path appropriately.
5-B) The thread path has a flaw.
Finish the thread path appropriately.
5-C) The thread path has an obstacle.
Finish the thread path appropriately to correct threading.
Trouble
Case (1)
Case (2)
Check and Corrective measures
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Summary of Contents for DDL-9000A
Page 14: ... 10 4 Feed locus and phase 1 Timing standard 2 Timing fast 3 Timing slow Standard Adjustment ...
Page 32: ... 28 8 Adjustment of the amount of feeding 4 Optional switch Standard Adjustment ...
Page 60: ... 56 11 Thread trimming unit 7 Replacement of the moving knife Standard Adjustment ...
Page 66: ... 62 11 Thread trimming unit 10 Adjustment of the drive arm stopper Standard Adjustment ...
Page 70: ... 66 12 Adjustment of the wiper DDL 9000A WB OB 2mm 1mm Standard Adjustment ...
Page 72: ... 68 13 Adjustment of feed lever pressure B A Feed lever Standard Adjustment ...
Page 112: ...MEMO ...