JUKI LH-3528 User manual

ENGLISH
INSTRUCTION MANUAL

CONTENTS
1. SPECIFICATIONS............................................................................................................ 1
2. NAME OF EACH COMPONENT ..................................................................................... 2
3. INSTALLATION................................................................................................................ 3
3-1. Caution at the time of set-up ................................................................................................................................ 3
3-2. Installation of the sewing machine ...................................................................................................................... 4
3-3. Adjusting the height of the knee lifter ................................................................................................................. 6
3-4. Installation of thread stand................................................................................................................................... 6
4. PREPARATION OF THE SEWING MACHINE ................................................................7
4-1. Method of lubrication ............................................................................................................................................ 7
4-2. Lubrication to the oil tank..................................................................................................................................... 8
4-3. Adjusting the amount of oil in the hook .............................................................................................................. 9
4-4. Oil in the feed box ................................................................................................................................................. 9
4-5. Applying grease................................................................................................................................................... 10
4-6. Installing the belt cover and the bobbin thread winder ................................................................................... 13
4-7. Attaching the needles ......................................................................................................................................... 13
4-8. How to take out the bobbin case ....................................................................................................................... 14
4-9. Insertlng a bobbin in a bobbin case .................................................................................................................. 14
4-10. Threading the machine head............................................................................................................................ 15
4-11. Thread tension ................................................................................................................................................... 16
4-12. Thread take-up spring....................................................................................................................................... 17
4-13. Adjusting the stitch length ............................................................................................................................... 18
4-14. Needle-to-hook relation .................................................................................................................................... 18
4-15. Adjusting the needle stop position.................................................................................................................. 20
4-16. Pedal pressure and pedal stroke ..................................................................................................................... 21
4-17. Adjustment of the pedal.................................................................................................................................... 21
5. OPERATION OF THE SEWING MACHINE .................................................................. 22
5-1. Pedal Operation ................................................................................................................................................... 22
5-2. Hand lifter............................................................................................................................................................. 22
5-3. Adjusting the pressure of the presser foot ....................................................................................................... 23
5-4. Micro-lifter ............................................................................................................................................................ 23
5-5. Thread tension release changeover when using the knee lifter ..................................................................... 24
5-6. One-touch manual reverse feed (One-touch reverse feed type)..................................................................... 24
6. MAINTENANCE ............................................................................................................. 25
6-1. Changing procedure to bottom feed and the adjustment ............................................................................... 25
6-2. Changing procedure to needle feed and the adjustment ................................................................................ 26
6-3. Adjusting the hook needle guard....................................................................................................................... 27
6-4. Adjusting the inner hook guide.......................................................................................................................... 27
6-5. Adjusting the height and the inclination of the feed dog ................................................................................ 28
6-6. Replacing the gauge ........................................................................................................................................... 29
6-7. Adjusting the thread presser spring.................................................................................................................. 30
6-8. Adjusting the position of the moving knife....................................................................................................... 31
6-9. Position of the wiper ........................................................................................................................................... 32
6-10. Caution when installing the attachments........................................................................................................ 32
6-11. Replacing the bobbin thread slack preventer sprlng (For LH-3568, 3568-7) ............................................... 33
6-12. Stop of the needle bars and angle of corners for corners stitching (For LH-3568, 3568-7) ....................... 33
7. STITCH-TO-ANGLE TABLE BY GAUGE (PITCH AND mm CONVERSION TABLE).. 34
8. GAUGE SETS................................................................................................................ 35
9. TROUBLES AND CORRECTIVE MEASURES ............................................................. 40
10. MOTOR PULLEY AND BELT ...................................................................................... 41

– 1 –
1. SPECIFICATIONS
Model name
Application
Hook
Thread trimmer
Separately
driven needle bar
mechanism
Max. sewing speed
Needle
Gauge size
Lift of presser foot
Lubrication
Noise
LH-3528 LH-3528-7
(with automatic thread trimmer)
For light- and medium-weight materials
S type : standard,F type : foundation, A type : light-weight materials, G type : jeans
Small hook
Not provided
Not provided
Small hook
Provided
Not provided
3,000 rpm
DP x 5 #9 to #16 (For F,A and S types), DP x 5 #16 to #22 (G type)
3/32" to 1-1/2"
2.4 to 38.1 mm
1/8" to 1-1/4"
3.2 to 31.8 mm
12 mm by knee lifter, 5.5 mm by hand lifter lever
JUKI NEW DEFRIX OIL No. 1 or JUKI MACHINE OIL #7
Workplace-related noise at sewing speed
n = 2,700 min–1 : Lpa ≦85 dB(A)
Noise measurement according to DIN 45635-48-A-1.
Model name
Application
Hook
Thread trimmer
Separately
driven needle bar
mechanism
Max. sewing speed
Needle
Gauge size
Lift of presser foot
Lubrication
Noise
LH-3568
(with incorporating corner stitching)
LH-3568-7
(with automatic thread trimmer
incorporating corner stitching)
For light- and medium-weight materials
S type : standard, G type : jeans
Small hook
Not provided
Provided
Small hook
Provided
Provided
3,000 rpm
DP x 5 #9 to #16 (S type), DP x 5 #16 to #22 (G type)
1/8" to 3/4"
3.2 to 19.1 mm
12 mm by knee lifter, 5.5 mm by hand lifter lever
JUKI NEW DEFRIX OIL No. 1 or JUKI MACHINE OIL #7
Workplace-related noise at sewing speed
n = 2,600 min–1 : Lpa ≦85 dB(A)
Noise measurement according to DIN 45635-48-A-1.

– 2 –
2. NAME OF EACH COMPONENT
1Separately driven needle
changeover lever
(LH-3568, LH-3568-7 only)
2Thread take-up cover
3Finger guard
4Thread tension controller
5Control box
6Pedal
7Knee padKnee pad
8Power switch
9Reverse feed switchReverse feed switch
!0 Operation panel
!1 Bobbin winder
!2 Thread stand
!3 Oil supply opening
!4 Reverse feed control lever
! Hand lifter lever
!0
2
3
6
5
8
7
4
9
!2
!4
!3
!
!1
1

– 3 –
3. INSTALLATION
Hold and transport the sewing machine with two
persons as shown in the illustration.
Do not put protr uding a rticles such as the
screwdriver and the like at the location where the
sewing machine is placed.
1) Transporting procedure of the sewing machine
2) Caution when placing the sewing machine
3-1. Caution at the time of set-up

– 4 –
3) Remove air vent cap 5attached to the
machine bed. (Be sure to attach cap 5when
transporting the machine head in the state
that the machine head is removed from the
machine table.)
3-2. Installation of the sewing machine
1) The under cover should rest on the four
corners of the machine table groove.
22.5 mm 18.5 mm
If the sewing machine is operated
without removing air vent cap 5,
oil leakage from gear box portion
Cmay occur.
2) Fix two rubber seats 1on side A(operator’
s side) using nails 2as illustrated above. Fix
two cushion seats 3on side B(hinged side)
using a rubber-based adhesive. Then place
under cover 4 on the xed seats.
(1) Installing the under cover
1
2
4
3
AB
C
5
1
3
1
3

– 5 –
4) Insert hinge 6into the machine main body.
Fit the machine head to table rubber hinges
7and place it on head cushions 8on the
four corners.
5) Attach head support rod 9to the table.
6) Remove inlet port !0 for circulation which
is xed to the oil tank installing plate, and
securely insert it into lter !1 until it goes
no further after removing cap !4 which is
attached to the end of the inlet port. Then set
the inlet port to D.
Place urethan lter !2 on E, and place lter
!3 of thin plate type (small mesh plate) on it.
6
6
7
9
8
7
D
E
!0
!1
!3
!2
!4
Circulation trouble may occur
unless inlet port !0 for circulation
is securely inserted into filer !1
until it goes no further.

– 6 –
3-3. Adjusting the height of the knee lifter
1) The standard height of the presser foot lifted
using the knee lifter is 12 mm.
2) You can adjust the presser foot lift up to 13
mm using knee lifter adjust screw 1.
Do not operate the sewing
machine in the state that the
presser foot 3is lifted by 12 mm
or more since the needle bar 2
comes in contact with the presser
foot 3.
3-4. Installation of thread stand
Assemble the thread stand, set it up on the machine table using the installation hole in the table and
tighten nut 1gently.
When you use power supplied by the overhead power line, pass the power supply cord through hollow
spool rest rod 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 off and ascertaining that the motor is at rest.
2
3
1
1
2

– 7 –
4-1. Method of lubrication
(1) Method of circulating lubrication (when the oil collected in the under cover is reused)
(2) Method of non-circulation type lubrication (when only the clean oil is always used)
 Periodically (approximately once in three months) clean the aforementioned lter
sections(fourplaces)inordertousethemachineforalongtime.Whenthelteris
clogged, lubrication trouble will occur and break-down will be caused.
In addition, when the oil becomes dirty, replace the oil gathered in the oil tank and
the under cover.
Put the cap to inlet port for circulation 1in the
same state as that at the time of delivery, and
securely fix it to the position where it does not
come in contact with the moving section.
* Remove drain screw 2and dump the oil
which has dropped to the under cover.
When inlet port for circulation
1comes in contact with the oil
surface, oil is absorbed without
passing the filter. As a result,
break-down will be caused.
Oil tank
Filter for circulation
Urethanlter
Filter for plunger
Plunger
Filter for plunger 2
4. PREPARATION OF THE SEWING MACHINE
1
2
Circulation
Lubrication to hook side
Lubrication
Circulation

– 8 –
4-2. Lubrication to the oil tank
Fill the oil tank with oil for hook lubrication before
operating the sewing machine.
1) Remove oil hole cap 1 and ll the oil tank
with JUKI NEW DEFRIX OIL No.1 (Part No.
: MDFRX1600C0) or JUKI MACHINE OIL #7
(Part No. : MML007600CA) using the oiler
supplied with the machine.
2) Fill the oil tank with the oil until the top end of
oil amount indicating rod 3comes between
the upper engraved marker line and the lower
engraved marker line of oil amount indicating
window 2.
If the oil is lled excessively, it will leak from
the air vent hole in the oil tank or proper
lubrication will be not performed. So, be
careful.
3) When you operate the sewing machine, rell
oil if the top end of oil amount indicating rod
3comes down to the lower engraved marker
line of oil amount indicating window 2.
WARNING :
1. Do not connect the power plug until the lubrication has been completed so as to prevent
accidents due to abrupt start of the sewing machine,
2. Topreventtheoccurrenceofaninammationorrash,immediatelywashtherelatedportionsif
oil adheres to your eyes or other parts of your body.
3. If oil is mistakenly swallowed, diarrhea or vomitting may occur. Put oil in a place where children
cannot reach.
3
2
1
Upper
engraved
marker line
Lower
engraved
marker line
 • Whenllingtheoiltankwiththeoilinitially,makesurethattheoilamount
indicating rod works. When it does not work at this time, make it work by tilting
the sewing machine once.
• When you use a new sewing machine or a sewing machine after an extended
period of disuse, use the sewing machine after performing break-in at 2,000 rpm
or less.
• For the oil for hook lubrication, purchase JUKI NEW DEFRIX OIL No. 1 (Part No. :
MDFRX1600C0) or JUKI MACHINE OIL #7 (Part No. : MML007600CA).
• Be sure to lubricate clean oil.
In case of the circulation type lubrication method, when using the sewing machine
forthersttime,theoilamountintheoiltankdecreasesuntiltheoilhascollected
intheler forcirculation.When thetopendof oilamountindicating rodislower
than the lower engraved marker line, add the oil to the oil tank again so that the top
end enters between the upper and lower engraved marker lines.

– 9 –
Adjust the amount oil using adjusting screw 1. Turn screw 1clockwise to increase the amount of oil
in the hook or counterclockwise to decrease it. Measure the amount of oil in ve seconds. When the
amount of oil is excessively decreased, break-down will be caused. So, be careful.
Oil splashes
Oil amount
decreases
Oil amount
increases
1
4-4. Oil in the feed box
When using the sewing machine, make sure that
the oil is put in the feed box from oil confirming
window 1.
Do not add oil to the feed box
since the adequate amount of oil
which is different from the hook
oil has been put in the feed box.
4-3. Adjusting the amount of oil in the hook
1
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 off and ascertaining that the motor is at rest.

– 10 –
• Never lubricate oil to the grease applying places.
• When grease is applied more than is necessary, there is a fear that grease leaks
from the thread take-up lever cover section or the needle bar. So, be careful.
• Be sure to use the grease contained in JUKI GREASE A TUBE (Part No. :
40006323) supplied with the machine head as accessories.
4-5. Applying grease
Periodically perform grease-up to the grease applying places of each model with cotton bar or the like
in order to use the sewing machine safely (the standard is once in 2 to 3 years). In case of the sewing
machines with thread trimmer (LH-3528-7 and -3568-7), when the time of grease-up has come, the
warning alarm sounds. When the alarm sounds, perform the grease-up.
[LH-3528, LH-3528-7]
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 off and ascertaining that the motor is at rest.
Thread take-up
lever (oil wick)
Needle bar Face plate
lubrication felt
A
[Grease keeping place]
The grease tube is installed on the inside of
window plate A.
Remove wiper cover 1, and apply grease to slot section 2of wiper solenoid base and wiper link collar 3.
1
2
3
[LH-3528-7, LH-3568-7]
Square block

– 11 –
Remove the rubber cap, take out the felt in A,
pour new grease in the hole, and put the felt to
which grease has been soaked after removing old
grease adhered to the inside of the hole and the
felt.
Further, pour grease above the felt and cover it
with the rubber cap.
[LH-3568, LH-3568-7]
[Common]
A
Thread take-up
lever (oil wick)
Felt
Needle bar bracket
Face plate
lubrication felt
Needle bar
Square block

– 12 –
[Releasing procedure of the grease-up warning] For SC-500
2
1
3
When a certain number of times of sewing has been performed, error code No. 220 1is displayed in
the control box at the time of turning ON the power, and warning buzzer sound ve times intermittently.
This warning informs of the grease replenishment time of the specied place. Be sure to perform grease
replenishment to the specied place. For the grease applying place, refer to "4-5. Applying grease", p.10
and 11. For the releasing procedure of the warning after grease replenishment, simultaneously pressing
2and 3, turn ON the power.
[Releasing procedure of the grease-up “error”] For SC-500
When the machine has been used for a certain period of time without performing grease-up after the
display of error code No. 220, error code No. 221 is displayed and the machine stops running.
At this time, be sure to execute grease replenishment to the specied place and perform releasing the
error in accordance with the aforementioned description.

– 13 –
4-7. Attaching the needles
[LH-3568, 3568-7]
[LH-3528, 3528-7]
Switch "off" the motor.
Use DPx5 needles.
1) Turn the handwheel until the needle bar has
come up to the highest point of its stroke.
2) Loosen needle clamp screws 2and pick up
two needles 1in the way that their grooves
3are facing outwards.
3) Insert the needles into the needle clamp as
far as they will go.
4) Tighten needle clamp screws 2 rmly.
4-6. Installing the belt cover and the bobbin thread winder
1) Drill guide holes A, B, Cand Dof wood screws in the table.
2) Adjust the position of bobbin thread winder 3, and x it to the place of guide holes Aand Bwith
wood screws.
3) Temporarily x belt cover B 1to the place of guide holes Cand D.
4) Install belt cover A 2to the arm installing section.
5) Adjust the position of belt cover B 1 and x it with wood screw.
A
C
B
D
67
44
95
75.5
12
(mm)
1
2
3
47
3
3
1
2
2
1
1
2
2
1
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 off and ascertaining that the motor is at rest.
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 off and ascertaining that the motor is at rest.

– 14 –
4-8. How to take out the bobbin case
1) Lift latch 1and take out the bobbin case and
the bobbin together.
2) Hold the bobbin case by latch raised, put
it into the shaft in the hook correctly and
release the latch.
4-9. Insertlng a bobbin in a bobbin case
[LH-3568, 3568-7]
1) Set a bobbin to the bobbin case so that the
bobbin turns in the direction of arrow mark A.
2) Pass the thread through thread slit 1in the
bobbin case and draw the thread and pull
the thread so that it passes under the tension
spring.
3) Pass thread through another thread slit 2
then, pass it through thread slit 3on the
bobbin case from the inside.
4) Put the thread on bobbin threads slack
preventer spring 4.
1
2
4
3
[LH-3528, 3528-7]
1
[LH-3568, 3568-7]
[LH-3528, 3528-7]
1) Set a bobbin to the bobbin case so that the
bobbin turns in the direction of arrow mark A.
2) Pass the thread through thread slit 1in the
hook and draw the thread and pull it so that it
passes under the tension spring.
A
A
1
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 off and ascertaining that the motor is at rest.

– 15 –
4-10. Threading the machine head
Thread the machine head following the order as illustrated in the gure.
Pass the left-hand needle thread, toward the machine head, in the order of 1to !. Pass the right-hand
needle thread in the order of Ato P.
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 off and ascertaining that the motor is at rest.
1. Be careful of threading of needle clamp thread guides (!4, O).
･FigureAforthinlamentthreadof#60orless
･FigureBforthicklamentthreadandpolyesterspunthreadof#50ormore
2. Pass right-side needle thread through the upper side of thread guide pin H.
3. Pass the thread through the intermediate thread guide of LH-3528-7 and -3568-7
as follows.
･Fig. C for polyester spun thread
･Fig. D for synthetic thread
1
2
A
B
9
6
8- I
7 H G
E
F
5
C
D
34
J
Intermediate
thread guide
!0 - K
!1 - L
!2 - M
!3 - N
!4
!
O
P
K
!0
Right-hand
needle thread
Left-hand
needle thread
Fig A Fig B
Fig C Fig D

– 16 –
1) Needle thread tension
Turn thread tension nut No. 2 1clockwise to
increase or counterclockwise to reduce the
needle thread tension.
2) Bobbin thread tension
Turn tension adjusting screw 2clockwise to
increase or counterclockwise to reduce the
bobbin thread tension.
4-11. Thread tension
1
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 off and ascertaining that the motor is at rest.

– 17 –
(2) When you want to change the tension of the thread take-up spring
1) Tension of thread take-up spring 1on the
right is adjustable by turning spring stud !3 to
the right to increase or to the left to reduce.
2) Tension of thread take-up spring 4on the left
is adjustable by turning spring stud !4 to the
right to increase or to the left to reduce.
1) Stroke of thread take-up spring 1on the right is adjustable by moving thread tension No. 2 asm.
3to the left or right after loosening thread tension No. 2 setscrew 2.
2) Stroke of thread take-up spring 4on the left is adjustable by moving thread tension No. 2 asm. 6
to the left or right after loosening thread tension No. 2 setscrew 5.
3) Move thread tension No. 2 asm. 3and 6to the right to increase or to the left to decrease the
stroke of the thread take-up spring.
When adjusting the stroke of thread take-up springs 1and 4, thread release pins
7and 8should not come in contact with disk release plate 9.
In addition, make sure that thread tension disks !1 and !2 securely rise when hand
lifter lever !0 is turned in the direction of the arrow.
4-12. Thread take-up spring
(1) When you want to change the stroke of the thread take-up spring
7
8
9
!1
!2
!0
2
63
4
5
1
To turn
!4
4
!3
1
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 off and ascertaining that the motor is at rest.

– 18 –
Turn stitch dial 1counterclockwise (clockwise)
to set the value on the dial corresponding to a
desired stitch length to the marker dot 3engraved
on the machine arm.
When it is hard to turn stitch dial 1, turn it while
slightly depressing reverse feed control lever 2.
• Reverse feed operation
1) Depress reverse feed control lever 2.
2) Reverse stitches are made as long as you
keep depressing the lever.
3) Release lever, and the machine will run
forward.
4-13. Adjusting the stitch length
4-14. Needle-to-hook relation
[LH-3528, 3528-7]
• Adjust the needle and the hook as follows.
1) Adjust the stitch dial to 2.5 on the scale.
2) Turn the handwheel to bring the needle bar to the lowest position and loosen needle bar connecting
stud clamping screw 1.
3) Determine the height of needle bar. The upper two of engraved marker lines are for DP X 5 needle,
and the lower two of them are for DP X 17 needle.
[Adjusting procedure for DP X 5 needle]
Adjust top engraved marker line Aof needle bar 2to the bottom end of needle bar rocking base 3,
and tighten the needle bar connecting stud clamping screw 1. At this time, the needle bar goes up by 2.2
mm from the lowest position (adjust the second engraved marker line Bto the bottom end of needle
bar rocking base 3) and the blade point of hook aligns with the center of needle. Then the distance
between the top end of needle eyelet and the blade point of hook becomes 1.2 mm.
[Adjusting procedure for DP X 17 needle]
Use the lower two of the engraved marker lines, and perform the adjustment by the same procedure as
that of [Adjusting procedure for DP X 5 needle].
1.2mm
2.2mm
3B
2
A
1
2
3
1
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 off and ascertaining that the motor is at rest.