– 23 –
1. Counter knife position
Loosen the counter knife set screw
to adjust the position.
2. Moving knife position
Loosen the screw
to adjust the position.
(Cautions) 1. In normal operation, the moving knife
passes in-
side the needle hole guide
, as illustrated in
A
A
A
A
A
.
2. The throat plate
is the appropriate item for the
LK-1900A Series (40006721).
Adjustment Procedures
Results of Improper Adjustment
o If the clearance is less than
0.5mm, thread may be cut by the
counter knife
blade when the
thread is pulled with the moving
knife
. In this case, upper and
lower threads are cut into short
pieces.
o If the clearance is more than
0.5mm, the residual thread length
after thread cutting operation be-
comes longer beneath the work.
1) Adjusting the height of the moving knife
Adjustments should be based on the plate thickness of the washer
in the above illustration. If the height seems to be inadequate,
select and use the parts as specified below.
2) Adjusting the height of the counter knife
Adjust the height by prying Part
A
with a screwdriver or the like.
Adjustment Procedures
Results of Improper Adjustment
o If the step is too small (0.25 ~
0.3mm) between the moving
and counter
knives, trouble in
thread cutting may occur.
o If the step is too large (0.1 ~
0.15mm) between the needle hole
guide
and the counter knife
,
thread may be cut by the counter
knife
blade when the thread is
pulled with the moving knife
.
In this case, upper and lower
threads are cut into short pieces.
Part No.
Name of part
Thickness
B242328000A
Moving knife washer
0.4mm
B242328000B
Moving knife washer
0.5mm
B242328000C
Moving knife washer
0.6mm
B242328000D
Moving knife washer
0.7mm
B242328000E
Moving knife washer
0.8mm
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 ...