JUKI LK-1910 Engineer's Manual page 29

Adjustment Procedures
1) Position of the counter knife
Loosen counter knife setscrews 1 to adjust it.
2) Position of the moving knife
Loosen screw 2 to adjust it.
(Caution) Under the normal operation, the moving knife
passes inside the needle hole guide as A shown
in the figure.
1) Adjusting the height of the moving knife
Adjust the height according to the thickness of the washer
described in the table below when the height is not proper.
Select and use the below-mentioned parts.
Part No.
B242328000A
B242328000B
B242328000C
B242328000D
2) Adjusting height of the counter knife.
Adjust the height by forcing section A with a screwdriver or
the like.
1) Grind side C when the thread on the side B is not cut, and
grind side B when the thread on the side C is not cut.
(Caution) When grinding the side, make the angle more
acuter than 90 degrees.
Name of part
Moving knife washer
Moving knife washer
Moving knife washer
Moving knife washer
Acute angle
Results of Improper Adjustment
™ When the clearance is 0.5 mm
or less :
When the moving knife pulls
threads, blade point of the
counter knife cuts the threads
and needle/bobbin threads are
cut short.
™ When the clearance is 0.5 mm
or more :
Length of the remaining thread
under the cloth after thread
trimming is lengthened.
™ If the level difference (0.25 to 0.3
mm) between the moving knife
and counter knife is small, it will
cause thread trimming failure.
™ If the level difference (0.1 to 0.15
mm) between the needle hole
Thickness
0.4 mm guide and the counter knife is
0.5 mm
large, when the moving knife
0.6 mm
pulls threads, blade point of the
0.7 mm
counter knife cuts the threads
and needle/bobbin threads are
cut short.
™ When the slant is less than 0.2 mm
: The thread on side C is not cut.
™ When the slant is more than 0.2 mm
: The thread on side B is not cut.
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