JUKI DNU-1541 Engineer's Manual page 27

Adjustment Procedures
The safety clutch functions when an excessive load is applied to
the hook driving shaft or the like during sewing. When the safety
clutch functions, the hook will not rotate even if turning the
handwheel, and the hook driving shaft sprocket wheel only will
run idle since the power is not transmitted to the hook driving shaft.
™ Resetting procedure
1. Checking the moving part of the sewing machine, and look for
and remove the cause which the safety clutch has functioned.
2. Pressing push button 1 located on the top surface of the
machine bed, strongly turn the handwheel in the reverse
direction of rotation.
3. Resetting procedure completes when the handwheel cannot
be turned with "click".
™ Adjusting the working torque of the safety clutch
1. Tilt the machine head.
2. Turn working torque adjusting screw 2 located at the periphery
of hook driving shaft sprocket wheel to adjust the working
torque.
™ Direction A : Working torque is large.
™ Direction B : Working torque is small.
Adjustment Procedures
1. Remove the plug of lubricating hole of oil tank.
2. Fill JUKI New Defrix Oil No. 2 up to line 2 of H (high) level
from lubricating hole 1 of oil tank. Check the oil amount once
a day and refill oil if it is below line 3 of L (low) level.
3. Adjustment of the amount of oil in the hook is performed with
oil amount adjustment screw 4 after loosening nut 5. Turning
the screw clockwise will increase the amount of oil in the hook,
or counterclockwise will decrease it.
4. The appropriate amount of oil, when a sheet of paper is placed
near the periphery of the hook, is to such an extent that splashes
of oil from the hook appear in approximately five seconds as
shown in the figure on the left.
Results of Improper Adjustment
Results of Improper Adjustment
When the amount of oil is short
™ Loose stitches will result.
™ Irregular stitches will result.
™ Hook is heated resulting in
seizure.
When the amount of oil is too much
™ Thread is stained with oil. In
addition, the cloth may be
stained.
23