– 43 –
1. If the dimensions of 0.3 x 8mm are not secured, retouching is re-
quired with the aid of an oil stone.
Adjustment Procedures
Results of Improper Adjustment
Part No.
Name of part
Remarks
0.8
14103253
Shuttle race ring A
1.3
14103352
Shuttle race ring B
1.7
14103659
Shuttle race ring C
1.9
B1817210DAD
Shuttle race ring D
Optional
Conforming to
Specifications F
and M as standard
Dimension A
(mm)
Conforming to
Specifications S
as standard
Conforming to
Specifications H
as standard
The standard stroke of thread take-up spring
is 8 to 10mm, and the
pressure at the start is 0.1 to 0.3N.
1) Adjusting the stroke
Loosen setscrew
, and turn thread tension asm.
.
Turning it clockwise will increase the moving amount and the thread
drawing amount will increase.
2) Adjusting the pressure
To change the pressure of the thread take-up spring
, insert a thin
screwdriver into the slot of thread tension post
while screw
is
tightened, and turn it. Turning it clockwise will increase the pressure
of the thread take-up spring
. Turning it counterclockwise will de-
crease the pressure.
Adjustment Procedures
Results of Improper Adjustment
Thread
Material
Needle thread
Thread take-up spring moving
Strength
tension setting
amount [ Thread drawing amount]
Tetoron thread #50
Wool
30 to 35
10mm [13mm]
0.1N
Spun thread #50
Wool
50 to 55
10mm [13mm]
0.2N
Spun thread #60
T/C broad
30 to 35
8 to 10mm [11 to 13mm]
0.1N
(Thread clamp OFF)
Cotton thread #50
Denim
35 to 45
10mm [13mm]
0.1N
Cotton thread #20
Denim
35 to 45
8 to 10mm [11 to 13mm]
0.1N
Example of the thread tension
When using the sewing machine for the first time, adjust the thread tension referring to the table below.
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 ...