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6-3) Moving knife does not spread
3-A) Initial position of the moving
Adjust the initial position of the moving knife.
threads.
knife is maladjusted.
3-B) Thread trimmer cam position
Adjust the thread trimmer cam position.
is inadequate.
3-C) Position of the shuttle upper
Adjust the position of shuttle upper spring .
spring is defective.
6-4) Stitch skipping at the final stitch
4-A) Timing of the needle to the
Adjust the timing and the clearance.
inner hook and the clearance
between them are defective.
4-B) Work clamp foot big.
Let the biginning of stitch come closer to the presser
by moving the pattern.
4-C) Loop of the needle thread
Attach the needle with the long groove orienting
falls down.
slightly to the right (approximately 20
°
)
6-5) Bobbin thread cannot be cut.
5-A) Bobbin thread tension is low.
Streng then the bobbin thread tension.
5-B) Needle hole size of the needle
Replace the needle hole guide with a new one having
hole guide is large.
a smaller hole diameter.
7. Poorly tense stitches
7-1) Tension controller No. 2 is
1-A) Tension of the tension controller
Properly adjust the tension of tension controller No. 2.
maladjusted.
No. 2 is low.
7-2) Tension controller No. 2 is
Adjust the thread tension releasing mechanism.
floating.
7-3) Thread take-up spring is
Adjust thread take-up spring tension and stroke.
maladjusted.
7-4) Clearance between the inner
4-A) The clearance between the
Properly adjust the clearance of inner hook and
hook and the shuttle driver is
inner hook and the shuttle
shuttle driver.
defective.
driver is too small.
7-5) Selection of the needle to be
5-A) Needle to be used is thin.
Replace the needle with a thicker one.
used is improper.
7-6) Selection of the needle hole
6-A) Hole diameter of the needle
Replace the needle hole guide with a new one having
guide is improper.
hole guide to the needle to be
a larger needle hole.
used and thread is small.
Trouble
Cause (1)
Cause (2)
Check and corrective measures
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Summary of Contents for LK-1900A
Page 20: ... 16 10 Hook adjustment Standard Adjustment 0mm 0mm 7 5mm 0 05 0 1mm For DPX5 For DPX17 ...
Page 90: ... 86 Grease Grease Grease Grease Grease 8 Needle thread clamp mechanism area ...
Page 91: ... 87 Grease Grease A Grease Grease Grease Grease 9 LK 1901A relations ...
Page 92: ... 88 10 LK 1903A relations Grease Grease ...
Page 114: ... 111 12 Circuit diagrams 1 Block diagram A ...
Page 115: ... 112 2 Power supply circuit diagram A ...
Page 116: ... 113 3 Power supply circuit diagram B ...
Page 117: ... 114 4 Power supply circuit diagram C ...
Page 118: ... 115 5 Servo motor circuit diagram ...
Page 119: ... 116 6 Sensor pedal VR circuit diagram ...
Page 120: ... 117 7 MAIN PANEL board circuit diagram ...
Page 121: ... 118 8 Motor solenoid circuit diagram Thread trimmer Lifting the work clamp foot motor ...