– 99 –
5. Thread breakage at the time of
5-1) Thread release timing is
1-A) Floating amount of the thread
Adjust the amount of thread tension No. 2 floating.
thread trimming.
defective.
tension disk No. 2 is small.
5-2) Thread spreading section of the
Paying attention to the blade section, polish with
moving knife has scratches.
polishing powder.
5-3) Shuttle upper spring has
Remove the scratches.
scratches.
5-4) Level difference between the
4-A) Thread is cut before trimming
Properly adjust the position of counter knife.
needle hole guide and the
with the blade section of the
counter knife is too high.
moving knife.
5-5) Clearance between the needle
5-A) Thread is cut before trimming
Properly adjust the position of counter knife.
hole guide and the counter
with the blade section of the
knife is too small.
moving knife.
5-6) Lower face of the needle hole
6-A) Thread is cut with the needle
Remove the scratches and polish with buff, or replace
guide has scratches.
hole guide.
the needle hole guide.
5-7) Thread spreading timing of
Adjust initial positions of the presser origin sensor,
the moving knife is defective.
thread trimmer, and the moving knife.
5-8) Thread take-up spring tension
Adjust the thread take-up spring.
is too low.
6. Defective thread trimming
6-1) Sharpness of the knife is
1-A) Worn-out of the moving and
Replace the moving and counter knives.
difective
counter knives.
1-B) Engagement of the moving
Properly adjust the heigh and position of the moving
and counter knives is defective.
and counter knives.
1-C) Parallel of the blade section
Properly adjust the parallel of the blade section of
of counter knife is defective.
counter knife.
1-D) Attaching position of the
Properly adjust the attaching position of counter knife.
counter knife is defective.
6-2) Double cutting for the needle
2-A) There is a burr on thread spreading
Paying attention to the blade section, polish with
thread. (Thread waste remains
section
A
of the moving knife.
polishing power, or replace the moving knife.
inside the cylinder arm cap.)
The shape of the thread
trimmed becomes and
thread waste remains.
2-B) Shuttle upper spring has scratches.
Remove the scratches.
(The shape of the thread trimmed
becomes and thread waste
remains.)
Trouble
Cause (1)
Cause (2)
Check and corrective measures
A
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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 ...