JUKI PLC-2760NVM User manual

PLC-2760NVM
INSTRUCTION MANUAL

ii
CONTENTS
1. Specications ................................................................................................................. 1
2. Threading the machine head......................................................................................... 2
3. Take-up thread guide ..................................................................................................... 3
4. Pneumatic components (when the pneumatic center guide is used) ....................... 4
5. Setting the incidental device......................................................................................... 6
5-1. Setting the ON/OFF status of the center guide ................................................... 6
5-2. Setting the optional input for the the center guide............................................. 8
5-3. Setting the optional output for the center guide ................................................ 9
6. Adjusting the hook needle guard................................................................................ 10
7. Adjusting the bobbin case opening lever .................................................................. 10
8. Adjusting the timing of the opener ............................................................................. 11
9. How to correct the main shaft reference angle ......................................................... 12
10. Position of the thread trimmer cam.......................................................................... 14
11. Adjusting the position of the moving knife.............................................................. 15
12. Adjusting the position of the clamp spring ............................................................. 16
13. How to adjust the cam timing.................................................................................... 17
13-1. Timing of the vertical feed cam ........................................................................ 17
13-2. Top feed cam timing .......................................................................................... 18
14. Needle sway (Adjusting the bottom feed amount).................................................. 20
15. Tension correction ..................................................................................................... 21
15-1. Tension correction and sewing speed ............................................................. 22
15-2. Tension correction and remaining amount of bobbin thread ........................ 23
16. Thread clamp device.................................................................................................. 25
16-1. How to install the thread clamp device............................................................ 25
16-2. How to set up the thread clamp device............................................................ 28
16-3. How to set the thread clamp operation while the presser foot is in its upper
position....................................................................................................................31
17. How to replace the hook cover ................................................................................. 32
18. How to install the oil lter.......................................................................................... 34
19. Counter function......................................................................................................... 35
19-1. Displaying the sewing screen under the counter display mode ................... 35
19-2. Types of the counter .......................................................................................... 35
19-3. How to set the counter ...................................................................................... 36
19-4. How to reset the count-completion state......................................................... 40
CAUTION
This Instruction Manual for the PLC-2760NVM only describes their differences from the
standard models (PLC-2760V).
For safety-related information, carefully read and fully understand "Safety precautions"
described in the Instruction Manual for the standard models before using your sewing ma-
chine.

– 1 –
1. Specications
PLC-2760NVMA70BBZ
No. Item Application
1 Model PLC-2760NVM
2 Model name 2-needle, post-bed, unison-feed, lockstitch machine with vertical-axis hook
3 Application Medium- to heavy-weight materials, car seat, furniture
4 Sewing speed Max. 2,500 sti/min
(Refer to "10. SEWING SPEED TABLE" in the Instruction Manual for the standard
model.)
5 Needle Ferd. SCHMETZ 134 - 35 (Nm 100 to Nm 180) (Standard : Nm 140)
6 Applicable thread size for sewing #30 to #5 (Europe 60 / 3-20 / 3)
7 Applicable thread size to be cut #30 to #5 (Europe 60 / 3-20 / 3)
8 Stitch length Max. 12 mm (forward/reverse feed)
However, the machine is shipped with its stitch length restricted to 7 mm.
9 Presser foot lift 20 mm
10 Presser foot pressure control Electric control (driven by a pulse motor)
11 Horizontal feed control Electric control (driven by a pulse motor)
12 Alternate vertical feed control Electric control (driven by a pulse motor)
13 Reverse stitch adjusting method Pulse motor driving (with touch-back switch)
14 Number of patterns Sewing pattern ............................ 99 patterns (For the polygonal shape sewing, as
many as 10 patterns can be registered.)
Cycle sewing pattern ................... 9 patterns
Custom-pitch pattern ................... 20 patterns
Condensation custom pattern ..... 9 patterns
15 Thread take-up Link thread take-up
16 Needle bar stroke 40 mm
17 Amount of the alternate vertical
movement
MAX. 9 mm
However, the machine is shipped with its stitch length restricted to 6.5 mm.
18 Needle thread tension Electric control (driven by a solenoid)
19 Hook Vertical-axis 1.6-fold hook (Latch type)
20 Feed mechanism Box feed
21 Drive system/Top and bottom
vertical axis drive
Main shaft direct drive system/Timing belt
22 Lubrication Automatic lubrication by semi-dry head plunger pump (with oil gauge)
23 Lubricating oil JUKI New Defrix Oil No. 1 (equivalent to ISO standard VG7)
or JUKI MACHINE OIL No. 7
24 Bed size 643 mm × 178 mm
25 Space under the arm 347 mm × 298 mm
26 Hand wheel size Outer diameter : ø123 mm
27 Motor/Control box DD motor : 800W AC servomotor
Control box : SC-952
28 Machine head weight 88 kg
29 Rated power consumption 600 VA
30 Noise - Equivalent continuous emission sound pressure level (LpA) at the
workstation:
A-weighted value of 83.5 dB; (Includes KpA = 2.5 dB); according to ISO
10821- C.6.2 - ISO 11204 GR2 at 2,500 sti/min.
-Sound power level (LWA);
A-weighted value of 90.5 dB; (Includes KWA = 2.5 dB); according to ISO
10821- C.6.2 - ISO 3744 GR2 at 2,500 sti/min.

– 2 –
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the following
work after turning the power o󰀨 and ascertaining that the motor is at rest.
2. Threading the machine head
Thread the machine head following the order as
illustrated in the gure.
󱀄
󱀁
󱀅
󱀂
󰿿
󱢳
󱀇
󱢴
󱢶
󱀃
󱢵
󱀀
󰿿
󱀀
󱀅
󱀂
󱀄
󱀂
󱀃󱀃
󱀅
󱀄
󱀇
󱢷
󱀆
󱀆
󱢸
Left-hand
needle thread Right-hand
needle thread
󱢸
󱢶
󱢷
󱀇

– 3 –
3. Take-up thread guide
If you want to change the feed amount of thread fed
from the thread take-up lever, loosen the setscrew of
take-up thread guide 󱀀and move take-up thread guide
󱀀appropriately.
Move the take-up thread guide in direction Ato de-
crease the thread feed amount.
Move the take-up thread guide in direction Bto in-
crease the thread feed amount.
* Standard position of the take-up thread guide
The position where take-up thread guide 󱀀is at its
lower end while the setscrew is fitted in the upper
tapped hole (󱤪) in the thread guide mounting plate 󰿿
(See the gure on the left.)
If you want to move the take-up thread guide in direc-
tion Bfrom its standard position, insert the setscrew of
take-up thread guide 󱀀into the lower tapped hole (󱤫)
in thread guide mounting plate 󰿿.
󰿿


󱤫
󱤪
󱀀
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the following
work after turning the power o󰀨 and ascertaining that the motor is at rest.

– 4 –
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power o󰀨 and ascertaining that the motor is at rest.
(1) Installing the regulator
1) Install regulator (asm.) 󰿿on mounting plate 󱀃
with screw 󱀀, spring washer 󱀁and nut 󱀂which
are supplied with the unit.
2) Attach joint 󱀄to inlet 1. Attach joint 󱀅to outlet
2.
3) Attach mounting plate 󱀃on the undersurface of
the table with accessory screws 󱀆supplied with
the plate.
4) Connect the ø6 air tube to joint 󱀅.
* Screw 󱀀which is supplied with the unit:
Thread diameter M5; Length: 12 mm
(SM6051202TP)
(2) Adjusting the air pressure
1) The operating air pressure is 0.5 to 0.55 MPa.
Adjust the air pressure using air pressure regulat-
ing knob 󰿿 of the lter regulator.
2) In the case uid accumulation is observed in 󱤨
section of the lter regulator, turn drain cock 󱀀to
drain the uid.
Decrease Increase
󰿿
󱀀
󱤨
󱀀
󰿿
󱀃
󱀅
󱀄
󱀂
󱀁
󱀆
1
2
4. Pneumatic components (when the pneumatic center guide is used)

– 5 –
󱀁
󱀂
󰿿
󱀀
󱀃
2ø4 tube
(3) Attaching the solenoid valve
1) Attach solenoid valve asm. 󱀀to the under-
surface of the table with accessory screw 󰿿
(SK3452001SE).
2) Connect the ø6 tube described in step 4) in "(1)
Installing the regulator" to joint 󱀁.
Cut the ø6 tube to an appropriate length before
use.
3) Connect the ø4 air tube coming from the air type
center guide to joint 󱀂.
4) Connect connector 󱀃to the CN59 on the electrical
control box.

– 6 –
5. Setting the incidental device
5-1. Setting the ON/OFF status of the center guide
󰿿
1) 󰿿held pressed for three second.
The "mode screen" is displayed.
2) Select "14. Incidental device setting".
3) The "Incidental device setting screen" is dis-
played.
When the device setting of which is to be
changed is selected, the setting screen for the
selected device is displayed.
4) Select "1. Center guide" to display the "Center
guide setting screen".
<Incidental device setting screen>
5) Select "H001 Function ON/OFF" to display the
"Center guide function ON/OFF setting screen".
<Center guide setting screen>

– 7 –
󱀀
󱀂
󱀄
<Center guide ON/OFF setting screen>
󱀁
󱀃
6) Select ON/OFF status of the function.
7) Press 󱀀to conrm the setting.
8) Press 󱀁to display the sewing data
edit screen.
9) Press 󱀂to display the "S056 center
guide".
10) Then, set the ON/OFF status of the center
guide.
11) Press 󱀃 to conrm the value you have
entered.
12) Press 󱀄to display the sewing screen.
If the pneumatic center guide does not function just by setting its ON/OFF status, set the optional in-
put/output of the center guide as described in the next paragraph to enable the function of the pneu-
matic center guide.

– 8 –
󰿿
5-2. Setting the optional input for the the center guide
Assign the switching function of the center guide to the 6-gang switch.
1) 󰿿held pressed for three second.
The "mode screen" is displayed.
2) Select "19. Optional I/O setting".
3) Select "1. Optional input setting".
4) Select "INPUT6. Thread clamp switch input".

– 9 –
󰿿
5) Select "i62. Center guide input".
6) Press 󱀀 to conrm the selection.
5-3. Setting the optional output for the center guide
1) Select "2. Optional output setting".
2) Select "OUTPUT11. Function is not provided".
3) Select "o25. Center guide".
4) Press 󰿿 to conrm the selection.
󱀀

– 10 –
6. Adjusting the hook needle guard
When a hook has been replaced, be sure to check the
position of the hook needle guard.
As the standard position of the hook needle guard, hook
needle guard 󱀀must push the side face of needle 󰿿to
lean the needle by 0.05 to 0.2 mm away from its straight
position.
If the aforementioned standard state is not achieved,
insert a screwdriver (small) 󱀂into needle guard ad-
justment screw 󱀁and adjust the position of the needle
guard.
1) Place the machine in the hook timing adjustment
mode.
2) To bend the hook needle guard in direction a, turn
the needle guard adjusting screw in direction A.
0.05 to
0.2 mm
󰿿
󱀀
󱀂
BA
󱀁
ab
A
󱀁
󱀂
󰿿
󱀀
0.2 to 0.3mm
󱀃
󱀄
1) Open the hook cover. (How to open : move the
hook cover to the right or left after lifting it right
above.)
2) Turn the handwheel in its normal rotational direc-
tion to bring bobbin case opening lever 󰿿to its
back end position.
3) Turn inner hook 󱀀in the direction of the arrow
until stopper 󱀁is pressed against the slits in throat
plate 󱀂.
4) Loosen bobbin case opening lever crank setscrew
󱀃. Adjust the clearance between the bobbin case
opening lever and protruding portion Aof the bob-
bin case to 0.2 to 0.3 mm.
5) Tighten setscrew 󱀃while pressing down bobbin
case opening lever crank 󱀄.
6) Move inner hook guide 󰿿up and down to make
sure that there is not play in the thrust direction.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the following
work after turning the power o󰀨 and ascertaining that the motor is at rest.
7. Adjusting the bobbin case opening lever
In case of 2-needle machine, perform the
same adjustment to the right and left hooks.
3) To bend the hook needle guard in direction b, turn the needle guard adjusting screw in direction B.
4) At the nal step of procedure, appropriately ad-just the clearance provided between the needle and the hook.
WARNING :
To protect against possible personal injury due to abrupt start of the sewing machine, be sure to change
over the operation mode to the "hook timing adjustment mode".
The presser foot automatically goes up when changing over the operation mode to the "hook timing
adjustment mode". In addition, the presser foot also comes down when the "hook timing adjustment
mode" is nished and the power is turned OFF. Be sure carry out the operation while keeping your hands,
etc. away from the presser foot.
For the sewing machine which is provided with the stitch skipping detecting device, the light emitted by
the sensor LED may light into the eye to cause dazzling when adjusting the hook timing.
To avoid this, cover the LED before adjusting the hook timing.

– 11 –
8. Adjusting the timing of the opener
󱀂
󱀁󱀁
0.2 to 0.5mm
󱀀
󰿿
󱤪
󱀂
󱀃
󱀄
Right hook 195±5°
Left hook 165±5°
[Conditions]
The displayed angle should be 0° when the
needle bar is at its upper dead point.
Angle display
1) Place the machine in the hook timing adjust-
ment mode.
2） For the right hook, loosen the setscrew in the
side cover on the operator's side to remove the
side cover.
(For the left hook, remove the side cover on
the opposite side of the operator.)
3） Loosen opener camsetscrew 󱀃.
4) While checking the angle displayed on the
screen, turn the handwheel to bring the hook
to the angle shown in the table. In this state,
tighten setscrew 󱀃of opener cam at the posi-
tion where opener 󰿿starts to move from the
position farthest from the protruding portion 󱤪
of inner hook 󱀀.
At this time, tighten setscrew 󱀃of opener cam
in such a way that a clearance of 0.2 to 0.5 mm
is provided between the top surface of opener
cam 󱀄and the undersurface of opener arm 󱀁󱀁.
5） Install the side cover with the side cover set-
screw.
6） Press button to exit from the hook timing
adjustment mode.
Carry out angle correction before start-
ing adjustment of the opener timing to
make sure that 0° is displayed when the
needle bar is at its upper dead point.
In the case of the 2-needle sewing ma-
chine, opener arm clamping screw 󱀂 of
the left hook is located on the opposite
side of the operator.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the following
work after turning the power o󰀨 and ascertaining that the motor is at rest.

– 12 –
9. How to correct the main shaft reference angle
1) Press and hold down 󰿿on the sewing
screen and select "9. Hook timing adjustment
mode".
2） Placing the dial gauge against the needle
clamp, turn the handwheel to bring the needle
bar to its upper dead point.
After you have adjusted the origins of the motors (main motor, feed motor, presser motor and alternating vertical
movement motor), correct the reference angle of the main motor.
Angle display
3） Check the angle displayed on the screen.
4） Press to return the screen to the sewing
screen.
5） Press 󰿿on the sewing screen to select
"1. Memory switch", "1. Display all" and "U120.
Main shaft reference angle correction" in the
written order.
󰿿

– 13 –
6) Enter a correction value on the operation panel
so that the angle you have checked in Step 3
becomes "0" (zero) or "360".
For example, enter "-5" if the angle you have
checked in Step 3 is "5". Enter "8" if the angle
you have checked is "352".
7) Press to conrm the value you have
entered.
8) Enter the "Hook timing adjustment mode".
Check that the angle "0" (zero) is displayed
when the needle bar is at its upper dead point.
Correction value
Angle display

– 14 –
10. Position of the thread trimmer cam
󱀅󱀅
󱀆󱀆
󱀅󱀅
󱀄
󱀃
󱀀󱀀󱀁󱀁
󱀇
󰿿
󱀂󱀂
0.1 to 0.2 
[Position of the thread trimmer cam]
1) Let the sewing machine fall down.
2) Set the thread trimmer solenoid to initial position.
3) Loosen three setscrews 󱀅of the thread trimmer solenoid mounting plate. Adjust the thread trimmer solenoid
mounting plate 󱀆so that the clearance between the thread trimmer cam roller 󱀀and the dwell section of
thread trimmer cam 󱀁is 0.1 to 0.2 mm in the state that the moving knife driving arm link 󱀃is in contact with
the roller 󱀄. Then tighten three setscrews 󱀅of the thread trimmer solenoid mounting plate.
4) Raise the sewing machine.
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the following
work after turning the power o󰀨 and ascertaining that the motor is at rest.
Close contact
Check that the end face of thread trimmer cam 󱀁 comes in close contact with the end face of collar 󱀂.
Fix the lower shaft set collar 󱀇 in a position so that the end face of lower shaft set collar 󱀇 is almost
aligned with the end face of lower shaft 󰿿.

– 15 –
11. Adjusting the position of the moving knife
1) Loosen the bed cover setscrews (1-needle machine: Two pieces; 2-needle machine: Four pieces) to remove
the bed cover.
2) Loosen clamping screw(s) 󰿿(1-needle machine: One piece; 2-needle machine: Two pieces) of the moving
knife shaft connecting arm A.
3) In the state where the at surface of the thread trimming cam and the cam roller come in contact with each
other, adjust the distance between the tip of counter knife 󱀁and the tip of moving knife 󱀀to 1.3 ± 0.1mm.
4) Tighten clamping screw(s) 󰿿(1-needle machine: One piece; 2-needle machine: Two pieces) of the moving
knife shaft connecting arm A in such a way that there is no thrust play in moving knife driving shaft 󱀂.
󰿿
󱀂󱀂
󱀁󱀁
󱀀󱀀
1.3 ± 0.1mm
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the following
work after turning the power o󰀨 and ascertaining that the motor is at rest.

– 16 –
󱀁󱀁
󱀃󱀃
󱀂󱀂
󰿿󰿿
󱀁󱀁
󰿿󰿿
󱀃󱀃
1
󱀀󱀀
Press against the end face
12. Adjusting the position of the clamp spring
WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the following
work after turning the power o󰀨 and ascertaining that the motor is at rest.
1) Loosen clamp spring setscrew 󰿿.
2) Move moving knife 󱀀to the position where it does
not come in contact with clamp spring 󱀁.
3) Slide clamp spring 󱀁while keeping it pressed
against the end face of counter knife base 󱀂.
4) Adjust clamp spring 󱀁so that it protrudes 1 mm
from the end face of counter knife 󱀃.
5) Tighten clamp spring setscrew 󰿿.
6) Return moving knife 󱀀to its initial position. Then,
check that it comes in light contact with clamp
spring 󱀁.
Press against
the end face

– 17 –
13. How to adjust the cam timing
13-1. Timing of the vertical feed cam
1) Adjust the vertical feed timing after you have
adjusted the horizontal feed timing.
2) Set the stitch length to "6.0" on the stitch length
screen.
* The PLC-2710V-7 and the PLC-2760V-7 have
di󰀨erent displays.
󱀁
󰿿
󱀀
󱀃󱀃
󱀂󱀂
Lower shaft
C
D
3) Press the standby switch. Then, tilt the ma-
chine head.
4) Loosen vertical feed cam setscrews 󱀃(two
pieces).
5) Turn vertical feed cam 󱀂in such a way that
needle 󰿿, throat plate 󱀀and feed dog 󱀁are
positioned as shown in the gure on the left.
6) Tighten vertical feed cam setscrews 󱀃(two
pieces).
[Conditions]
Amount of feed: 6 mm
Alternating vertical movement amount: 3 mm
When the needle comes down and the feed dog
goes up
Top end of the eyelet of needle 󰿿, top surface of throat
plate 󱀀 and top surface of feed dog 󱀁 are aligned
WARNING :
To protect against possible personal injury due to abrupt startup of the sewing machine, be sure to
press the standby switch and conrm that the screen has changed over to the standby mode screen
before starting work.

– 18 –
13-2. Top feed cam timing
1) Set the stitch length to "6.0" on the stitch length
screen.
* The PLC-2710V-7 and the PLC-2760V-7 have
di󰀨erent displays.
2) Set the amount of the alternating vertical
movement of the walking foot and presser foot
to "3.0" on the alternating vertical movement
amount screen.
* The PLC-2710V-7 and the PLC-2760V-7 have
di󰀨erent displays.
WARNING :
To protect against possible personal injury due to abrupt startup of the sewing machine, be sure to
press the standby switch and conrm that the screen has changed over to the standby mode screen
before starting work.