JUKI AK-157 User manual

INSTRUCTION MANUAL
AK-157

i
CONTENTS
1. FEATURES.............................................................................................. 1
2. INSTALLATION ....................................................................................... 2
(1) Replacing the AK lever (asm.)..............................................................................2
(2) Installing the presser sensor detection plate.....................................................3
(3) Subassembling the AK motor ..............................................................................3
(4) Installing the AK motor.........................................................................................5
(5) Checking the assembly ........................................................................................6
(6) Connection.............................................................................................................7
(7) Selecting with / without the AK device................................................................7
(8) Adjusting the sensor.............................................................................................8

This is the auto-lifter incorporating the cam which is driven by the stepping motor.
①After the presser foot is lifted by the auto-lifter, it is retained at its upper position by the cam. As a
result, the power consumption is reduced.
②Since this auto-lifter does not produce solenoid-like impact noise, the comfortable work environ-
ment is maintained.
③Function for reducing the presser foot pressure at the beginning of sewing
In the case the needle thread cannot be brought under the material while the thread presser de-
vice (NB device) is used, the assistance function that reduces the presser foot pressure at the
beginning of sewing to allow the needle thread to be smoothly brought under the material can be
set.
* Refer to [ Handling of troubles that occur at the beginning of sewing ] in "5-2. Adjusting the nee-
dle thread presser device" in the Instruction Manual for how to set the assistance function.
1. FEATURES
– 1 –

WARNING :
Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the
sewing machine.
2. INSTALLATION
1) Loosen setscrew ❷of side plate ❶. Remove
side plate ❶.
3) Loosen presser-lever fulcrum shaft setscrew
❹from above the top of the arm. Remove
presser-lever fulcrum shaft ❺.
1. Apply the grease supplied with the
unit to each joining section.
2. Press AK lever asm. ❻against the
sewing machine frame. Then, move
the former so that it is spaced 0.1 mm
from the latter. In this state, fasten
presser lever fulcrum shaft setscrew
❹to secure presser lever fulcrum
shaft ❺.
Check to make sure that AK lever asm.
❻moves smoothly.
Check to make sure that the slit a
in presser lever fulcrum shaft ❺is
positioned horizontally.
5) Attach knee-lifter connecting rod ❼to the
AK lever. Fix cable clip band ❽in the hole
through which knee-lifter connecting rod ❼of
AK lever is to be passed through. Then, insert
knee-lifter connecting rod ❼into the cable
clip band.
4) Install AK lever asm. ❻which is provided with
a roller instead of the removed parts.
* For the AK device which is purchased in the shipped state, it has already been factory-adjusted.
❻
❺
❻
❺
a
❻
❼
❽
Provided
with a roller
0.1mm
Fig. A
❶
❷
❸
AK lever (asm.)
2) Remove knee-lifter bar hinge screw ❸.
❹
(1) Replacing the AK lever (asm.)
– 2 –

❶
❸❷
Detecting portion (leftward)
Fig. B
❹
❺
❶
❷❹
(2) Installing the presser sensor detection plate
1) Attach presser detector plate ❶to knee lifter
link plate ❸with screw ❷.
At this time, the orientation of presser detec-
tor plate ❶should be as shown in Fig. B
(3) Subassembling the AK motor
1) Attach presser lifter motor ❶to motor mount-
ing plate ❷with four hexagon socket head
bolts ❸.
Fig. C
2.2 to 2.5mm
❶
❷
❸
2) Attach cam ❹to presser lifter motor ❶with
setscrew ❺.
At this time, adjust the clearance provided be-
tween motor mounting plate ❷and cam ❹to
2.2 to 2.5 mm.
(See Fig. C.)
* It is recommended to sub-assemble the parts
while putting a 2.5-mm hexagonal wrench key
between the motor mounting plate and cam
to obtain the clearance of 2.2 to 2.5 mm.
– 3 –

Position of
screw ❾
Completed state of subassembly
3) Attach sensor ❻to sensor mounting plate ❼
with screw with washer ❽.
Attach sensor mounting plate ❼to motor
mounting plate ❷with screw ❾.
At this time, attach the sensor mounting plate
❼by tightening screw ❾at its center of slot.
4) Connect junction cable 󱢳to sensor ❻.
❷
❼
❾
❻
❼
❽
❼
󱢳
❻
– 4 –

1) There is a marker line on the surface of cam 󱢶.
Adjust so that marker line Aon the cam and
end face B of motor xing plate ❾are collinear
to each other.
2) Temporarily fix presser motor asm. 󱢴with
three presser motor asm. setscrews 󱢳.
At this time, move presser motor asm.
󱢴
up
and down to adjust its position to such a posi-
tion that it does not lift up cam roller
󱢵
. (After
the adjustment, the presser foot is in the oat-
ing state.)
Adjust presser motor asm. 󱢴so that
cables and wires located inside the
sewing machine are positioned above
the xing plate ❾.If the cables and wires
are positioned under the xing plate ❾,
they will interfere with the cam 󱢶.
󱢶
❾
󱢳
󱢳
󱢴
If the cam roller 󱢵is
raised, the problem
that the presser foot
sole fails to come in
contact with the throat
plate can occur.
Collinear
󱢶
❻
󱢵
Light-contact state
󱢶❾
B
A
Securely tighten three presser motor asm. set-
screws 󱢳while bringing cam roller 󱢵and cam
󱢶into light contact with each other. (Check to
make sure that the presser foot sole does not
oat above the feed dog.)
(4) Installing the AK motor
– 5 –

❷
❶
❸
(5) Checking the assembly
1) Operate presser foot lifting lever ❸to check
to make sure that detector plate ❶does not
interfere with sensor ❷.
– 6 –

❸❷
❹
❶
❺
A B
❶
❸
❷
(6) Connection
1) Connect the junction cable connector to
presser foot lifting motor ❶and electrical box
❷.
Bind the extra length of cable with cable clip
band ❸.
(7) Selecting with / without the AK device
1) Turn power ❺ON while keeping ❶
held pressed. The function setting screen is
displayed.
2) Press ❷to set setting No. Ato
"107". Then, press ❸ to ash set value
B ON and OFF.
3) Press ❷to set the set value B to
"0". Then, press ❹.
– 7 –

❸❷
❹
❶
❺
A B
Align
(8) Adjusting the sensor 1) Turn power ❺ON while keeping
❶held pressed. The func-
tion setting screen is displayed.
2) Press ❶.
The screen is changed over to
the sewing mode screen.
3) Depress the back part of pedal.
The origin is retrieved and the
presser foot is held at its upper
position. Depress the back part
of pedal again to lift the presser
foot.
4) Keep ❶held pressed.
The function setting screen is dis-
played.
5) While the function setting No.
ashes ON and OFF, press
❷to set the function set-
ting No. A to "123".
6) Press ❸ to ash set value B ON and
OFF.
Press ❷. Then the cam rotates
by the number of pulses corresponding to
the number of times you have pressed
❷by pressing ❹.
Adjust so that the marker line on the cam 󱢶
is aligned with the edge of plate ❾.
* If you have failed to follow the correct step of
procedure in the middle of operation, do not
press ❹. Instead, press ❶to
exit from the function setting screen.
With the aforementioned measure, it is pos-
sible to exit from the function setting screen
without saving the data you have changed.
󱢶❾
󱢶
❾
– 8 –