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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.
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