JUKI LU-2810 Series User manual

PARTS & INSTRUCTION MANUAL
EDGE CUTTING DEVICE WITH COUNTER KNIFE
JUKI LU2810

TABLE OF CONTENTS Page:
Notes of Safety 2
Electrical Schematic 3
1. Mounting the Edge Cutting Unit 3
2. Functional description 3
3. Mode of Operation 4
4. Knife Change 5
5. Knife Adjustments 6
6. Adjusting the Edge Stop 7
7. Knife Speed 7
8. Knife Input Delay 7
9. Source of Error 8
1 . Maintenance 8
Images 9
Knife Adjusting Guidelines 12
Electrical Diagram 13
Parts List 14

NOTES OF SAFETY
1. The machine must only be commissioned in full knowledge of the instruction
book and operated by persons with appropriate training.
2. Before putting into service also read the safety rules and instructions of the motor
supplier.
3. The machine must be used only for the purpose intended. Use of the machine
without the safety devices is not permitted. Observe all the relevant safety
regulations.
. When gauge parts are exchanged (e.g. needle, presser foot, needle plate, feed
dog and bobbin), when threading, when the workplace is left, and during service
work, the machine must be disconnected from the mains by switching off the
master switch or disconnecting the mains plug.
5. Daily servicing work must be carried out only by appropriately trained persons.
6. Repairs, conversion and special maintenance work must only be carried out by
technicians or persons with appropriate training.
7. For service or repair work on pneumatic systems the machine must be
disconnected from the compressed air supply system. Exceptions to this are only
adjustments and function checks made by appropriately trained technicians.
8. Work on the electrical equipment must be carried out only by electricians or
appropriately trained persons.
9. Work on parts and systems under electric current is not permitted, except as
specified in regulations DIN VDE 0105.
10. Conversions or changes to the machine must be authorized by us and made only
in adherence to all safety regulations.
11. For repairs, only replacement parts approved by us must be used.

1. Mounting the Edge Cutting Unit
The edge cutting unit is mounted from the rear onto the machine. The
respective adapter plate for the corresponding sewing machine is
included in the kit.
Possibly some drillings must be made according to the attached drill plan.
1.1 Installation of the motor control
The drive for the edge cutter is screwed under the table.
Electrical connection:
ATTENTION: Risk of death by electric shock!!!
The motor controller is allowed to be connected by
qualified electrical only!
Unplug the power plug before working on electrical
equipment!
Secure the power cord from accidentally reconnecting!
Make sure to observe the correct voltage (100-250 V AC, 7-63 Hz). All
other connections see enclosed circuit diagram.
It is recommended to us a machine main switch!
2. Functional Description
Right beside the needle a special punching knife is arranged, that cuts
perpendicularly from above.
In the needle plate a tungsten carbide counter knife is attached.
The upper knife is driven by a direct current gear motor.
By the motor start signal a pneumatic cylinder is switched on for lowering the knife.
The control works with an appropriate tip-switch or via a knee-lever switch.
The edge cutting device is characterized by the following:
-Additional attachment onto usual flat-bed- or post-bed-machines
-Very high life time of the knifes
-Very fast and simple knife change
-The upper knife can be sharpened
-Knife speed is adjustable
-Cutting distances: 1.2 – 6.0 mm

Attention: At devices with an edge cutting distance of 1.2-2.5 mm the
maximum pass length is 4 mm. The maximum needle size
at a cutting distance of 1.2-1.5 mm is N 90. At non-
compliance of these defaults needle breakage and the
destruction of the needle plate and the lower knife is the
result.
3.0 ode of Operation
Switching ON or OFF is made by a push-button or by a knee-lever-switch.
The knee-lever-switch is not part of the scope of delivery. If
necessary it must be ordered separately!
Following functions are possible by the knife control (fig.2):
a) Knife motor off
b) Cutting stop – foot lift up
Is this toggle switch placed “ON” the knife drives upward
when the foot is lifted up and begins automatically to run
when lowering again.
c) Cutting stop – seam end
Is this rocker switch switched “ON” the knife turns off
automatically after the end of the seam (L.G. impulse). The
renewed switching on of the knife is made by a push-button or
by knee levers.
d) Automatic OFF/ON
-If the toggle-switch is turned to “Automatic OFF/AUS“
the usual mode of operation is applicable that means the
blade runs even when the machine stops.
-If the toggle-switch is turned to “Automatic ON/EIN“ the
knife is only running while sewing.
* Only activate the toggle-switch when the knife is
turned off

Process:
-Turn OFF the knife
-Turn toggle-switch “Automatic ON/EIN“
-Turn on the knife at the green “Power”-button
-The knife is running into the cutting position without starting
-As soon as the sewing machine is sewing the knife starts cutting and stops
again together with the sewing machine
-The auxiliary functions “cutting stop feet lift-up” as well as “cutting
stop seam end” can be also connected if necessary.
This new auxiliary function can be an advantage with certain material
outlines, particularly because thereby the knife abrasion is lowered
3.1 Finger protection
Each machine is equipped by us with a protecting device.
This can be ordered both as a Plexiglas as well as a wire protection.
4.0 Knife Change
If the parts are not cut through cleanly or if the cutting edge is frayed the knife
has to be changed or regrinded.
The upper knife can be regrinded. (grind device – Id.-No: - 66838 -) The
lower knife cannot be regrinded.
ATTENTION: Before knife change the main switch at the sewing
machine has to be switched OFF !
4.1 Changing the upper knife
If the main-switch is switched off the knife drives into the upper position (fig.1) -
Loosen screws “3“ and change the knife
I PORTANT: The knife must be installed all the way up to the
knife stop “4“! (fig 1)
4.2 Changing the lower knife
-Loosen both screws “5” on the stitch plate
-Set in the new lower knife

ATTENTION: Pay close attention to the correct installation of the lower
knife!
The lower knife has a special grinding. The cusp of the knife must point at the
upper knife.
If the new knife is installed, please control as follows:
-Switch on the main-switch at the sewing machine
-Turn the toggle-switch at the knife motor to “OFF“ (fig.2)
-Turn on the punching knife with the knurled screw to the upper dead point
-Switch on the knife by the push button or by the knee lever
-Now the knife drives into its working position. The driving motor is still
switched off.
-Rev up the motor once by the knurled screw, fastened on the motor shaft
and check the knife impact. Make a thread test as follows: When manual
spinning the wheel, a thread must be cut through perfectly.
-If the knife impact is correct, push the push-button once again (knife goes
upwards) and throw the toggle-switch “1“ (fig.1) to “ON“ again.
-Now you can start working again!
5. Knife Adjustments
ATTENTION:
Before adjusting the kniv
es
–
turn OFF the ma
in
-
switch at the
sewing machine!
-By loosening screws “6“ (fig.1) the knife can be adjusted to the sewing
direction.
-By adjusting the stop “ “ (fig. 1) the impact depth of the knife can be
adjusted.
-By the stop-bolt “1“ (fig.1) the blade pressure can be defined
-The lower knife fixed and cannot be adjusted
-The twist from the upper to the lower knife can be adjusted as follows:
Loosen screw “5” (fig.1) and
twist eccentric “7”
-The knife throw is defined by the integrated eccentric
-The top dead center and/or the bottom dead center is adjusted via the
screws “1” (fig.3)

ATTENTION:
At the following procedures a cutting test must be made
(see item 3. ):
-changing the upper knife
-changing the lower knife
-changing the stitch plate
These knife adjustments are already set by MJF at assembly and
normally never have to be changed!
6. Adjusting the Edge Stop
For post-bed-machines a pneumatic stop is attached at the machine bed. This
stop is activated by a pneumatic toggle switch.
The stop width is adjusted either by shifting the cylinder “1” or by shifting the
stopper “2” inside the cylinder.
7. Knife speed
The maximum knife speed is adjusted by MJF. By the rotary knob (h) (fig.2)
the knife speed can be regulated.
With the left potentiometer on the control board (fig.5) the maximum
blade speed can be adjusted and with the right potentiometer the
minimum blade speed.
These settings are made prior to delivery and should not be changed!
8. Knife switch-on delay time
By knife switch-on delay time one understands the time from the knife
lowering impulse to the knife approach impulse.
3 time adjustments are possible:
1. Rotary switch 1 to 0 = 0.1 sec (preset)
2. Rotary switch 1 to 2 = 0.5 sec
3. Rotary switch 1 to = 1.0 sec
Likewise one can affect the switch-on time over the throttle in the inlet to the
remote cylinder.

The speed of the knife depends on the material which has to be processed, as
well as on the number of revolutions of the sewing machine and/or the stitch
length.
IMPORTANT: The more slowly the knife speed, the more service life of
the knives!
9. Source of error
9.1 Knife does not cut
-Check if the lower knife is correctly installed
-Check the blade of the lower knife
-Check cutting pressure, over cut and screwing
9.2 Knife motor does not start
-finger protection has to be folded down
-turn higher the potentiometer speed
-check the position of the switches at the control unit (knife motor “ON” ?)
-check the knife of smoothness (turn by hand)
-check compressed air
1 . Maintenance
10.1 The edge cutting tool is extensively maintenance-free, however the oiling points
we marked on the pictures, should be oiled twice weekly.

10.2 Screws "5" and “6” are for adjusting the bearing play.
This attitude is already preset by MJF. The screws are secured. (Fig. )
ATTENTION: When readjusting the bearing play behind:
The edge cutting device must be smooth-running,
when the motor is rotated manually!!!
ATTENTION: With all maintenance and adjustment works switch off
the main switches!!!

Fig.1
Fig.2

Fig.3
Fig.4

ADJUSTING GUIDELINES
Edge Cutter with
Counter Knife
In order to improve the lifetime of the knife edge as long as possible, the
following adjustments are very important:
1.)
Knife height
2.)
Adjustment of the knife in sewing direction
3.)
Cutting angle between upper and lower knife
.)
Pressure of the cutting edge
5.)
Following the installation instructions
F
ig. 5

Knife height
At the lower dead center between knife point and needle plate cutout
must be a gap of 0.5 mm. If the knife is at the upper center, the cut
surface of the knife must reside against the counter knife.
If the knife height is adjusted, loosen screws “G” and recalibrate the knife
stop.

Adjustment of the knife in sewing direction
After loosening of the screws “E“ the knife holder can be pushed
forwards or back.
Cutting angle between upper and lower knife
This means that the knife, if it goes downward should have an easy
shears effect, i.e. at the knife point, if it is not installed and adjusted to
drop completely below the lower knife, a small gap will be shown. The
smaller the cutting angle, the longer the lifetime of the knife.

Loosen screw “C“.
Rotate the eccentric bush with the fork wrench “A“ gently.
Then tighten screw “C“ again.
Now the guide bolt “B“ must be rotated with a fork wrench in such a way
that the cutting bracket runs again easily.

Pressure of the cutting edge
By loosening of the screws “H“ and adjusting of the stop screw “D“ the
pressure of the cutting edge is adjusted.
If the knife is above, it must reside against the counter knife in the
needle plate easily.

Instruction of installation
During assembly of the edge cutter it is absolutely necessary that the
knife surface stands exactly rectangular to the upper edge of the needle
plate.

M
J
F