– 27 –
o Improperly positioned upper
knife arm shaft will come in
contact with the frame.
If it is moved with the position of
the upper knife unchanged,
proper engagement of the knives
will be disturbed, prohibiting
sharp cutting of the knives.
1) Remove the upper cover, loosen setscrew
in upper knife driving
arm
, and turn upper knife shaft
to adjust the position from the
top surface of the throat plate to 34 mm.
(Caution) Be sure to fully tighten the setscrew since upper knife
shaft
is subjected to high load.
o The lower knife, if positioned too
high, will catch materials or
cause no contact of the presser
foot with the throat plate top sur-
face.
o If the lower knife is positioned too
low, the cutting width will be
changed or materials will be
caught by the lower knife.
o The upper knife, if positioned too
high, will fail to cut materials.
o Failure of cutting or abnormal
wear on the knives will result
unless the lower knife is laterally
positioned and fixed at a position
where it has settled by itself un-
der the upper knife spring.
1) Lower knife
1
Adjust the vertical position of the lower knife by screw
so that the
blade top aligns with the top surface of the throat plate.
2
Tighten screw
after bringing the upper knife to its lowest position
of its stroke.
2) Upper knife
1
Adjust the position of the upper knife by screw
so that the engage-
ment with the lower knife is 0.5 to 1 mm when the upper knife is in the
lowest position of its stroke.
(Caution) Adjust the lateral position of the lower knife by screw
.
Adjust the lateral position of the upper knife by screw
.
After performing adjustment, be sure to fix the knife. Oth-
erwise, the durability of the knife will be affected.
3) Overedging width
1
Adjust the overedging width in the following way :
Laterally position the upper knife before loosening screw
.
Tighten screw
when the upper knife has settled by itself under the
pressure applied by the spring. Repeat this adjustment procedure to
obtain desired overedging width.
Adjustment Procedure
Results of Improper Adjustment
Adjustment Procedure
Results of Improper Adjustment
Summary of Contents for MO-6700D Series
Page 49: ...45 2 Upper looper components...