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1-5) The bobbin thread is too short
5-A) Bobbin idling pulls the edge of
Increase the pressure of the bobbin presser.
at sewing start.
the bobbin thread into the bobbin
case.
Increase the bobbin thread tension.
5-B) The pressure of the bobbin
Reduce the pressure of the bobbin presser.
presser is too high.
However, be careful not to idle the bobbin.
5-C) A flaw on the hook causes the
Repair the flaw on the hook, or replace the hook.
bobbin thread to be cut too short.
1-6) Knot tying between the needle
6-A) The sewing speed at sewing
Conduct 1 or 2 stitches of soft-start at the sewing start.
and bobbin threads is not easy
start is too fast to knot the needle
at sewing start.
and bobbin threads together.
2. The edge of the needle thread comes
2-1) The needle thread passing through
1-A) The 1st thread tension is too low.
Increase the 1st thread tension.
out on the material at the sewing start.
the needle is too long after thread
trimming.
1-B) The timing of the tread trimming
Inspect and adjust the standard timing of the thread
is too late.
trimming cam with reference to 3. - (11) -1).
1-C) The counter knife is set too back.
Adjust the counter knife with reference to 3. - (11) -4).
3. The underside of the material is not
3-1) The needle thread passing through
1-A) Refer to the previous item, [The
Refer to the previous item, [The needle thread passing
neat at sewing start.
the needle is too long after thread
needle thread passing through
through the needle is too long after thread trimming].
(The needle thread remains long under
trimming.
the needle is too long after thread
the material.)
trimming].
3-2) Adjustment of the throat plate,
2-A) Refer to the previous item,
Refer to the previous item, [An inappropriate needle, throat
needle, or foot is inappropriate,
[An inappropriate needle, throat
plate, or presser is used. Alternatively, the pressure of the
and the needle thread passing
plate, or presser is used.
presser is too low].
through the needle cannot be
Alternatively, the pressure of
shortened after thread trimming.
the presser is too low].
Trouble
Case (1)
Case (2)
Check and Corrective measures
From the previous page
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 ...
