– 19 –
1. Apply a proper amount of grease (Juki Grease A) to the grooved cam block of the cam
, the peripheral cam
block, and the rollers of the presser bar lifter link
and the thread trimmer link
. Refer to “9.-(4) Parts to
which grease is applied.”
2. While the cam
is being inserted in the shaft of the presser lifting motor
, mount the assembly on the
sewing machine frame and tighten the four set screws
. The insertion of the cam should be done gently in
order not to hurt the bearing
.
3. Clearance B toward the presser bar lifter link
and Clearance A toward the thread trimmer link
should be
equally distributed. For this purpose, adjust the position of the cam
and fix it with the use of the two set
screws
. (Apply the screws to the flat section at both ends of the shaft.)
* If it is difficult to examine Clearance B, Clearance A should be adjusted to 0.5mm ~ 0.7mm during assembly.
4. Mount the sensor slit
with the two set screws
so that the end plane of the motor shaft can approxi-
mately coincide with that of the sensor slit
. (Join the flat section for installation.)
* Confirm that the slit plate of the sensor slit
does not interfere with the presser bar lifter sensor.
5. Refer to “(12) Thread trimmer and presser foot origin sensor adjustment” and make sensor adjustments.
Procedures of assembling
1. Start the test mode CP-6.
2. Tread on the pedal for the retrieval of the thread trimmer and presser
bar lifter (cam) origin.
3. Using a bar
or the like, confirm that the standard holes
A
and
B
of the sewing machine frame coincide with the standard hole
C
of
the thread trimmer and presser bar lifter cam
.
4. If the standard hole
C
of the thread trimmer and presser bar lifter
cam
stays in the upper
E
direction, loosen the set screw
to
move the sensor mounting plate
in the lower
D
direction and then
fix it. If the standard hole
C
of the thread trimmer and presser bar
lifter cam
stays in the lower
D
direction, loosen the set screw
to move the sensor mounting plate
in the upper
E
direction and
then fix it. After the sensor mounting plate
has been fixed, tread
on the pedal for the retrieval of the thread trimmer and presser bar
lifter (cam) origin to confirm whether the standard holes coincide with
each other.
5. Repeat the above steps 2 to 4 until the coincidence is confirmed.
(Caution) Confirm that there is no mutual interference between the
sensor slit plate
and the sensor before tightening the
set screw
.
Adjustment Procedures
Results of Improper Adjustment
o If there is no coincidence of the
standard holes, such a condition
is regarded as a thread cutting
timing error. This can be a cause
of trouble in thread breakage or
unthreading at the beginning of
sewing.
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 ...