JUKI FLS-350N Series Quick start guide

R
ENGINEER’S MANUAL
29311107
No.01
Electronic Handstitching Machine
FLS-350N Series

PREFACE
This Engineer’s Manual is written for the technical personnel who are responsible for the service and maintenance
of the machine.
The Instruction Manual for this machine intended for the maintenance personnel and operators at an apparel
factory contains operating instructions in detail. And this manual describes “Standard Adjustment”, Adjustment
Procedures”, “Results of Improper Adjustment”, and other important information which are not covered in the
Instruction Manual.
It is advisable to use the relevant Instruction Manual and Parts List together with this Engineer’s Manual when
carrying out the maintenance service of this machine.
Regarding the motor for the sewing machine with automatic thread trimmer, separately refer to the Instruction
Manual for the motor and Engineer’s Manual. In addition, for the control panel, refer to the Instruction Manual
for the control panel.
This manual gives the “Standard Adjustment” on the former page under which the most basic adjustment value
is described and on the latter page the “Adjustment Procedures” and “Results of Improper Adjustment” under
which the steps of adjusting procedure, and stitching errors and troubles arising from mechanical failures are
described.

CONTENTS
1. SPECIFICATIONS ...................................................................................... 1
2. EXPLANATION OF UNITS......................................................................... 2
(1) Configuration .............................................................................................................2
(2) Operation panel (1Operation panel) .......................................................................3
3. EXPLANATION OF STITCH LENGTH COMPENSATION FUNCTION..... 5
(1) Function.....................................................................................................................5
1) In case the upper stitch becomes small...........................................................................................5
2) In case the upper stitch becomes large ...........................................................................................5
(2) Operation...................................................................................................................5
4. NEEDLE BAR CURVE AND TIMING ADJUSTMENT CHART ................. 6
5. STANDARD ADJUSTMENT ...................................................................... 8
(1) Before making the adjustments ................................................................................8
(2) Adjusting the home position (adjusting the graduation)............................................8
(3) Adjusting the needle bar groove cam and the left looper cam ...............................10
(4) Adjusting the needle bar.........................................................................................12
1) Adjusting the height of the support cylinder of the upper needle bar.............................................12
2) Adjusting the height of the support cylinder of the lower needle bar .............................................12
3) Adjusting the timing of transferring the needle ..............................................................................14
4) Centering the needle bar ...............................................................................................................14
(5) Adjusting the needle guide claw .............................................................................16
1) Adjusting the needle and the needle guide claw ...........................................................................16
2) Adjusting the thread tension of the needle guide claw ..................................................................16
3) Adjusting the timing of opening/closing the tubular cam of the needle guide claw........................18
(6) Adjusting the thread path guide..............................................................................18
(7) Adjusting the thread haul lever ...............................................................................20
1) Cam timing.....................................................................................................................................20
2) Adjusting the thread haul lever ......................................................................................................20
(8) Adjusting the brush cam .........................................................................................22
(9) Adjusting the hook finger ........................................................................................22
1)Adjusting the movement amount of the hook finger .......................................................................22
2) Adjusting the rotating shaft and the tension spring........................................................................24
3) Adjusting the clearance between the hook finger and the needle .................................................24
(10) Adjusting the hook finger to release the thread tension .......................................26
(11) Adjusting the eccentric amount of the eccentric pin .............................................26
(12) Adjusting the lower feed .......................................................................................28
1) Adjusting the feed eccentric boss and the lifting cam....................................................................28
2) Adjusting the height of the lower feed dog and the throat plate.....................................................28
(13) Adjusting the upper feed dog and the lower feed dog ..........................................30
(14) Adjusting the presser foot.....................................................................................30
(15) Adjusting the upper feed eccentric shaft ..............................................................32

(16) Adjusting the left looper ........................................................................................32
(17) Adjusting the right looper cam..............................................................................34
(18) Adjusting the right looper......................................................................................34
1) Adjusting the right looper pin .........................................................................................................34
2) Adjusting the relationship between the right looper and the needle ..............................................36
(19) Adjusting the position of the ellipse gear..............................................................36
(20) Adjusting the lower looper ....................................................................................38
1) Adjusting the lower looper arm ......................................................................................................38
2) Disassembling and assembling the lower looper...........................................................................38
(21) Adjusting the command block and the proximity sensor ......................................40
(22) Adjusting the feed, reverse stitching position, and the proximity sensors ............40
(23) Adjusting the needle stopping position.................................................................42
(24) Adjusting the tension of the timing belt of the feed stepping motor......................44
(25) Adjusting the threader needle during replacement...............................................44
(26) Adjusting the angle of the foot pedal, and the foot pressure of the pedal (FLS-350N only) ..... 46
(27) Servomotor controller box connection diagram ....................................................46
(28) Disassembling/assembling the needle bar...........................................................48
(29) Removing the snap ring when disassembling the needle bar ..............................50
6. ELECTRICAL COMPONENTS ................................................................ 52
(1) Printed circuit boards in the control box..................................................................52
7. MAINTENANCE AND INSPECTION ....................................................... 53
(1) Electrical components.............................................................................................53
(2) Mechanical components.........................................................................................53
(3) Consumable parts replacing period table ...............................................................55
8. ERROR CODES ....................................................................................... 56
9. TROUBLES AND CORRECTIVE MEASURES ....................................... 57
(1) Mechanical components.........................................................................................57
(2) Electrical components.............................................................................................59
10. TIME CHART.......................................................................................... 61
11. CIRCUIT DIAGRAM ............................................................................... 62
(1) Layout drawing of the control box...........................................................................62
(2) Circuit diagram........................................................................................................63
(3) Cable wring diagram...............................................................................................64
12. DRWAING OF THE TABLE ................................................................... 65

−1−
1. SPECIFICATIONS
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Item
Model
Sewing speed
Stitch length
(Max. total length of
top/bottom stitches)
Reversefeedstitching
Stitch specifications
Needle *
Thread
(Thread recommended
by JUKI)
Thread length
Type of stitch
Feed type
Change-overofupper
and lower stitch
mechanism (Cloth
feed mechanism)
Threading
Presser foot lifting
method
Presser foot lift
Material thickness
Safety mechanism
Lubricating oil
Grease
Dimensions
Weight of machine
Input power voltage
Power consumption
Motor
Specifications
FLS-350NA
140 to 400 rpm
(300 rpm or less for
synthetic thread)
* It is necessary to change the needle bar when changing the needle size.
0.6 mm to 8 mm
(Up to 16 mm)
FLS-350N
120 to 400 rpm
(300 rpm or less for
synthetic thread)
FLS-351NA
140 to 300 rpm
(250 rpm or less for
easing in of fullness)
0.6 mm to 8 mm
(Up to 16 mm)
In case of easing in of
fullness with synthetic
thread : 0.6 mm to 3 mm
(Up to 6 mm)
ORGAN DPN-1032B/32
KANAGAWA
Co. KNK400mZ
FUJIX Co. KING FIT #60
(Synthetic thread)
Sewing thread 1,200 mm
or less
Actuated by push-button (Stitch length is fixed at 1 to 2 mm for both top / bottom stitches)
1-needle, 1-thread, special stitching (handstitching type)
Short-long stitch Saddle stitch
Top and bottom feed type
Change of upper and lower stitch feed amount by a stepping motor
Manual operation
By a knee-lifter lever
7 mm (when the knee-lifter lever is used)
Max. 2.5 mm
Drum cover open / close protection switch (when opening the drum cover, the sewing machine is not
actuated even when the foot pedal is depressed.)
JUKI New Defrix Oil No. 2 (equivalent to ISO VG32)
ESSO TEMPLEX Grease N2 containing 10g (Part No. 13552206)
Main unit : 1,070 mm (width) X 660 mm (depth) (FLS-350N : 715 mm) X 1,120 mm (height)
Table : 1,200 mm (width) X 800 mm (depth) X 870 to 910 mm (height)
300Kg
700W
SC-1 SC-380
Single phase :
100V, 200V 50 / 60 Hz Single phase : 200V, 220V, 230V, 240V, 380V, 50 / 60 Hz 3-phase : 200V, 220V, 230V, 240V, 380V, 50 / 60Hz
FLS-350NB
140 to 300 rpm
ORGAN DPN-1032B/49
ACE CROWN
Tetoron #8
Sewing thread 1,000
mm or less
ORGAN DPN-1032B/38
FUJIX Co. KING handstitching machine thread
(for light-weight materials)
FUJIX Co. KING FIT #60 (Synthetic thread)
Sewing thread 1,200 mm or less

−2−
2. EXPLANATION OF UNITS
(1) Configuration
!1
!4 !5
!6
!7
!8
!9
@0
@1
@2
@3
1Operation panel
2Reverse stitch switch
™The machine perfomes reverse stitching as long as the push-button is held pressed. The machine resumes
normal stitching when the push-button is released.
(Caution) Reverse stitching should be carried out at the lowest speed within the range of 1 to 3 stitches.
3Sewing machine light
™It lights up when turning the knob mounted on the top of the lamp.
™The lamp support rod is flexible and can be tilted as desired.
(Caution) Unless the power switch is turned ON, the lamp will not light up since the lamp is not energized.
4Handle
This handle can be operated manually.
5Main power switch
™Press the “1” side of the switch, and the control circuit will be energized.
The indicator lamps on the control panel will light up, and the motor that controls the feed mechanism and
the sewing machine will be actuated to retrieve the origin.
™Press the “0” side of the switch, and the power to the machine will be turned OFF.
6Knee-lifter lever
Shift the lever to the right, and the presser foot will go up.
7Drum cover opening/closing knob
When loosening the knob and opening the cover, the safety device will be actuated, and the sewing machine
will not be actuated even when the foot pedal is depressed.
@4
@5
@6
@7
@8
@9
31
1
2
4
5
6
7
8
9
!0
!2
!3

−3−
8Sewing machine foot pedal
™The machine changes the sewing speed from low to high by gradually increasing depressing the front part
of the foot pedal.
™After releasing the foot pedal, the needle will stop at the intermediate resting position in its stroke. (The
needle has two different intermediate resting positions.)
™When this side of the foot pedal is depressed, the needle will stop at the upper position.
™The lowest speed is fixed at 140 rpm (120 rpm) (Depending on the specifications).
9Table fixing clip
™It is used when opening/closing or fixing the machine table.
!0 Presser lifter fixing knob
™The presser foot and the top feed dog can be fixed with this knob.
!1 Slide plate
™The drum and underside of the throat plate can be observed by shifting the slide plate.
!2 Thread trimming blade
™The blade is used to cut and hold the thread.
!3 Table
!4 Head cover
™Open the head cover when replacing the needle.
™Open the head cover when disassembling the needle bar for cleaning.
!55 Eye-guard
™It is a cover that protects eye from a broken needle that jumps out of position.
!6 AC servo-motor
!7 Control box
!8 Needle threading lever
™It is used to thread the needle.
!9 Caster
@0 Adjusting bolt
@1 Thread stand (packed in the accessory box)
@2 Thread guide
™This is a guide that works when drawing thread placed on the spool rest rod.
@3 Stitch ruler
(2) Operation panel (1Operation panel)
@4 Sewing speed LED indicator
The LED lights up to indicate the sewing speed specified by the setting variable resistor locating on the right of
the LED.
@5 Stitch length LED indicator
The LED lights up to indicate the stitch length specified by the setting variable resistor locating on the right of
the LED.
@6 Sewing speed setting variable resistor
Turning this variable resistor clockwise will increase the number of revolutions.
@7 Stitch length setting variable resistor
Turning this variable resistor clockwise will increase the stitch length.
@8 Right side/wrong side stitch indicator
This indicates whether the stitch length is on the upper side or on the lower side.
@9 Stitch selector switch
Pressing the push-button switch changes the right side stitches to the wrong side stitches.

−4−

−5−
3. EXPLANATION OF STITCH LENGTH COMPENSATION FUNCTION
(1) Function
When changing over the upper stitch length or the lower stitch length (turn ON/OFF the stitch length changing
switch.), it is ideal if the stitches are as illustrated in the figure below.
However, there may rarely be some machines, which make the sticthes as shown in the figure below when the
short sticth length is changed to upper stitch or lower stitch.
1) In case the upper stitch becomes small
2) In case the upper stitch becomes large
As shown in the above figure, the upper stitch is not the same as the lower stitch when the stitch length is
changed.
At this time, adjust the stitch length changing variable resistor so that the upper and lower stitches become the
same by adding the stitch length of section (b) of the above figure.
(2) Operation 1) In case of a > a’
1In case of a > a’, the lower stitch is larger than the
upper stitch. Add the compensation amount to the
upper stitch length.
In this case, press up the stitch length change switch,
and adjust the stitch length change variable resistor
so that the lower stitch becomes the same as the upper
stitch.
2) In case of a < a’
2In case of a < a’, add the compensation amount to
the lower stitch length as the upper stitch is larger than
the lower stitch.
In this case, press down the stitch length change
switch, and adjust the stitch length change variable
resistor so that the lower stitch becomes the same as
the upper stitch.
Upper stitch
Lower stitch
Change-over of
stitch length
a = a’
Upper stitch
Lower stitch
aa’
Upper stitch
Lower stitch
Upper stitch
Lower stitch
a
a’
a
Change-over of
stitch length
In case of a > a’
Upper stitch
Lower stitch
Upper stitch
Lower stitch
a
a’
a
Change-over of
stitch length
In case of a < a’
Stitch length
change switch
Up
Small
Stitch length change
variable resistor
Down
Large
(b)
(b)

−6−
4. NEEDLE BAR CURVE AND TIMING ADJUSTMENT CHART
1
• Adjusting the home
position (5.-(2))
• Adjusting the needle bar
groove cam and the left
looper cam (5.-(3))
• Adjusting the lower feed
(5.-(12))
• Adjusting the feed
eccentric boss and the
lifting cam (5.-(12)-1)
• Adjusting the presser
(5.-(14))
2
• Adjusting the height of
the upper needle bar
support cylinder
(5.-(4)-1))
• Adjusting the height of
the lower needle bar
support cylinder
(5.-(4)-2))
• Adjusting the timing of
transferring the needle
(5.-(4)-3))
• Centering the needle bar
(5.-(4)-4))
3
• Adjusting the needle and
the needle guide claws
(5.-(5)-1))
• Adjusting the timing of
opening/closing the
tubular cam of the needle
guide claw (5.-(5)-3))
• Adjusting the thread
tension of the needle
guide claws
(5.-(5)-2))
4
• Adjusting the lower
looper (5.-(20))
Points to be adjusted for each timing
10˚ 20˚ 30˚ 40˚ 50˚ 60˚ 70˚ 80˚ 90˚ 100˚ 110˚ 120˚ 130˚ 140˚ 150˚ 160˚ 170˚ 180˚
2˚
42˚
29.4˚
72.4˚ 75.4˚ 90˚
Needle bar
(upper)
Needle bar
(lower)
12 438