JUKI LK-1900AN - Page 33

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Procedures of assembling
1. Apply a proper amount of grease (JUKI Grease A) to the grooved cam block of the cam
1
, the pe-
ripheral cam block, and the rollers of the presser bar lifter link
8
and the thread trimmer link
9
. Refer
to "9.-(4) Parts to which grease is applied."
2. While the cam
1
is being inserted in the shaft of the presser lifting motor
6
, mount the assembly
on the sewing machine frame and tighten the four set screws
5
. The insertion of the cam should be
done gently in order not to hurt the bearing
7
.
3. Clearance B toward the presser bar lifter link
8
and Clearance A toward the thread trimmer link
9
should be equally distributed. For this purpose, adjust the position of the cam
1
and x it with the use
of the two set screws
2
. (Apply the screws to the at section at both ends of the shaft.)
* If it is difcult to examine Clearance B, Clearance A should be adjusted to 0.5 to 0.7 mm during as-
sembly.
4. Mount the sensor slit
3
with the two set screws
4
so that the end plane of the motor shaft can ap-
proximately coincide with that of the sensor slit
3
. (Join the at section for installation.)
* Conrm that the slit plate of the sensor slit
3
does not interfere with the presser bar lifter sensor.
5. Refer to "(13) Thread trimmer and presser foot origin sensor adjustment" and make sensor adjust-
ments.
Adjustment procedures Results of Improper adjustment
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 (2.5 mm hexagonal wrench key corresponding)
4
or the like, conrm 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
1
.
4. If the standard hole
C
of the thread trimmer and presser bar
lifter cam
1
stays in the upper
E
direction, loosen the set
screw
2
to move the sensor mounting plate
3
in the lower
D
direction and then x it. If the standard hole
C
of the thread
trimmer and presser bar lifter cam
1
stays in the lower
D
direction, loosen the set screw
2
to move the sensor mounting
plate
3
in the upper
E
direction and then x it. After the sen-
sor mounting plate
3
has been xed, push the start switch for
the retrieval of the thread trimmer and presser bar lifter (cam)
origin to conrm whether the standard holes coincide with each
other.
5. Repeat the above steps 2. to 4. until the coincidence is con-
rmed.
(Caution) Conrm that there is no mutual interference be-
tween the sensor slit plate
5
and the sensor before
tightening the set screw
2
.
o
If there is no coincidence of the
standard holes, such a condition
is regarded as a thread trimmer
timing error. This can be a cause
of trouble in thread trimmer or
unthreading at the beginning of
sewing.