– 90 –
1. Skipping of one or more stitches occurs
1-1) The needle thread passing through
1-A) Something is wrong with the
Check needle thread routing, thread entangled on thread
at the start of sewing.
the needle is too short after
needle threat route and the
guide rod the direction, and position of thread stand or
thread trimming.
needle thread tension is too
thread entangled on it.
high at thread trimming.
1-B) The tension of the 1st thread
Turn the thread tension nut of the 1st thread tension disk
tension disk is too high.
counterclockwise to decrease the tension.
1-C) The floating amount of the 2nd
Check whether the floating amount of the 2nd thread tension
thread tension disk is insufficient
disk reads between 0.5 and 1 mm when the hook thread
at thread trimming.
presser is pushed into until the tip of the presser reaches
the bobbin.
The floating amount is adjustable by moving the tension
release wire on the underside of the bed.
Check whether the disk is horizontally loosened. If not, turn
the thread tension spring 180 degrees or correct the spring
inclination.
1-D) The timing of the tread trimming
Inspect and adjust the standard timing of the thread
cam is too early.
trimming cam with reference to 3. - (11) -3). Adjust the
timing to red or colorless type.
1-E) The needle thread is detached
If there is a clearance at the tip of the hook thread presser
at thread trimming due to wrong
when the plunger is pushed by a finger toput the thread
position of the hook thread
trimming solenoid into the suction state and the hook thread
presser.
presser is pushed into until the tip of the presser reaches the
bobbin, conduct readjustment with reference to 3.-(11) -9).
1-F) The counter knife is too close
Check whether the position of the counter knife is correct
to the needle, or the knife tip
and the moving knife has a flaw after removing the throat
is too sharp.
plate. [3.-(11) -4), -5), -7) and -8)]
1-G) The knife thread guide, moving
Check whether the hole portion of the hook (especially the
knife, or hook has a flaw.
blade top) or knife thread guide has a flaw. If there is a flaw
there, buff the flaw portion sufficiently. If the flaw portion is
large, replace the part.
1-H) The lifting amount of the auto-
Excessive rise of the auto-lifter device causes the thread
lifter device (AK-141) is too
guide with presser bar guide to rise rapidly and the needle
large.
thread to be pulled by the thread take-up spring resulting in
shortened needle thread. Readjust the rise amount of the
AK device to approx. 8.5 mm. Alternatively, set the remaining
amount of the needle thread relatively longer for use of the
AK device.
Trouble
Case (1)
Case (2)
Check and Corrective measures
To the next page
9. Troubles and corrective measures
(1) Mechanical parts
Summary of Contents for DDL-9000B-DS
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 58: ... 54 11 Thread trimming unit 8 Replacement of the moving knife Standard Adjustment ...
Page 70: ... 66 12 Adjustment of the wiper DDL 9000B WB 2mm 1mm Standard Adjustment ...
Page 112: ...MEMO ...
