JUKI MF-7923 - Adjusting the Looper; Adjusting the Height of the Needle

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6. Adjusting the looper
0 to 0.05 mm
1
A
5
4
[Lateral position]
The relation between clearance
A
between looper
1
and the center of right-hand needle and the needle
gauge is as shown in the table.
Loosen clamp screw
2
and laterally adjust looper
holder
3
in accordance with the table.
[Longitudinal position]
Adjust so that the clearance between blade point
5
of
the looper and medium needle
4
is 0 to 0.05 mm when
the top end of the looper comes from the extreme right
position to the center of the medium needle. After the
adjustment, tighten clamp screw
2
to x the looper.
* The blade point of the looper comes in contact with
the right-hand needle when rear needle guard
6
does not work. So, be careful.
7. Adjusting the height of the needle
A
B
C
1
2
A
6
1
2
3
Reference : Height from the top surface of the throat
plate
A
to the top end of left-hand needle,
C
when the needle is in the higher dead
point is as shown in the table.
1) Equally adjust clearance
A
between needles
1
and
needle holes
2
in the throat plate.
2) Adjust the needle bar height so that the top end of
the left-hand needle eyelet aligns with the bottom
end of looper when the looper travels from the
extreme right position to the left until the top end
B
of the looper protrudes from the left end of the left-
hand needle by approximately 1 to 1.2 mm. Then,
remove rubber cap
4
from the face plate, and
tighten needle bar connection setscrew
3
.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the fol-
lowing work after turning the power off and ascertaining that the motor is at rest.
2-needle 3-needle
Needle gauge Return amount
A
Needle gauge Return amount
A
3.2 4.3
4.0 3.9
4.8 3.5
5.6
3.1 5.6 3.1
6.4 2.7 6.4 2.7
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the fol-
lowing work after turning the power off and ascertaining that the motor is at rest.
Unit : mm
2-needle 3-needle
Needle gauge Height of left-
hand needle,
C
Needle gauge Height of left-
hand needle,
C
3.2 8.9
4.0 8.6
4.8
8.1
5.6 7.8 5.6 7.8
6.4 7.3 6.4 7.3
Unit : mm
3
4