JUKI LK-1942ZA5050, Instruction Manual And Parts List

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4. Bobbin case loading detecting device
(1) Adjusting the sensor
Standard adjustment Adjustment procedures Results of improper adjustment
0.2mm
1. As a guide, a clearance of 0.2 mm
should be provided between the
sensor slit plate and the sensor.
It should be noted that the sensor
should not come in contact with
the sensor slit plate.
Faulty detection can occur.
Sensor failure is caused.
(2) Position of the bobbin case holder positioning finger
Standard adjustment Adjustment procedures Results of improper adjustment
Top end
1. Discharge air.
2. Remove the bobbin case from the
hook. The slit in the top end of the
cylinder should be pushed against
the bobbin case shaft when the
cylinder is retracted the most.
3. Turn the power ON.
4. Load the bobbin case in the hook.
The sensor should be turned ON
with the top end of the cylinder
pushed against the bobbin case.
5. Remove the bobbin case from the
hook. The sensor should be turned
OFF when the cylinder is retracted
the most.
Faulty detection can occur.
5. Detection of stitch skipping and detection of no bobbin-thread
Standard adjustment Adjustment procedures Results of improper adjustment
❶
❶
❷
❸
❷
❹
Stitch skipping
detection sensor
No bobbin-
thread detection
sensor
1. Turn ON the power to the
sewing machine to activate
the sensors.
2. Loosen screws ❶ and ❷
shown in the figure until
they can be moved.
3. Adjust screws ❶ and ❷
so that the stitch skipping
detection sensor light
illuminates the center of
reflective seal ❸ and so
that the no bobbin-thread
detection sensor light does
not illuminate the needle
but illuminates the center
of reflective seal ❹ .
Faulty detection can occur.