LH-4128,28-7,68-7,88-7 INSTRUCTION MANUAL (ENGLISH) · 3) Press ng the s de of front cover !5 n the d rect on of the arrow, open the front cover toward you. Be sure to open / close

ENGLISH

�v

CONTENTS

1. SPECIFICATIONS ........................................................................................................... 12. NAME OF EACH COMPONENT .................................................................................... 23. INSTALLATION ............................................................................................................... 3

3-1. Installing the bottom cover .................................................................................................................................. 33-2. Opening and closing of the control box (SC-910) ............................................................................................. 43-3. Adjusting the height of the knee lifter ................................................................................................................ 43-4. Installation of thread stand .................................................................................................................................. 53-5. Caution when installing the panel ...................................................................................................................... 53-6. Connecting the cord ............................................................................................................................................. 63-7. Managing the cord ................................................................................................................................................ 83-8. Adjusting the knee lifter detection seat (asm.) ................................................................................................ 10

4. PREPARATION OF THE SEWING MACHINE ............................................................. 114-1. Lubrication .......................................................................................................................................................... 114-2.Cleaningthefilter ............................................................................................................................................... 124-3. Adjusting the amount of oil in the hook .......................................................................................................... 134-4. Attaching the needles ........................................................................................................................................ 134-5. How to take out the bobbin case ...................................................................................................................... 144-6. Inserting a bobbin in a bobbin case ................................................................................................................. 144-7. Threading the machine head ............................................................................................................................. 154-8. Thread tension .................................................................................................................................................... 164-9. Thread take-up spring ........................................................................................................................................ 164-10. Adjusting the stitch length .............................................................................................................................. 174-11. Winding the bobbin thread .............................................................................................................................. 184-12. Adjusting the needle stop position ................................................................................................................. 194-13. Pedal pressure and pedal stroke .................................................................................................................... 204-14. Adjustment of the pedal ................................................................................................................................... 20

5. OPARATION OF THE SEWING MACHINE .................................................................. 215-1. Pedal operation ................................................................................................................................................... 215-2. Hand lifter ............................................................................................................................................................ 225-3. Adjusting the pressure of the presser foot ...................................................................................................... 225-4. Thread tension release changeover when using the knee lifter .................................................................... 235-5. Separately driven needle changeover switch (for LH-4168-7 and 4188-7) .................................................... 245-6. One-touch reverse feed switch lever (for touch-back) ................................................................................... 25

6. MAINTENANCE ............................................................................................................ 256-1. Changing procedure to bottom feed and the adjustment (LH-4128 without thread trimmer only)............. 256-2. Changing procedure to needle feed (for LH-4128 only) ................................................................................. 276-3. Adjusting the inner hook guide ......................................................................................................................... 286-4. Needle-to-hook relation ..................................................................................................................................... 296-5. Adjusting the height and the inclination of the feed dog ............................................................................... 326-6. Adjusting the presser foot ................................................................................................................................. 326-7. Move (adjustment) of the hook shaft saddle when replacing the gauge ...................................................... 336-8. Lubricating route when changing the needle gauge size ............................................................................... 336-9. Adjusting the thread presser spring ................................................................................................................. 336-10. Adjusting the position of the moving knife .................................................................................................... 346-11. Replacing the bobbin thread slack preventer spring (for LH-4168-7 and 4188-7) ...................................... 356-12. Adjusting the hook needle guard .................................................................................................................... 356-13. Stop of the needle bars and angle of corners for corners stitching (for LH-4168-7 and 4188-7) ............... 366-14. Caution when installing the gauge to the bed slide ...................................................................................... 366-15. Position of the wiper ........................................................................................................................................ 376-16.Replenishinggreasetothespecifiedplaces(forLH-4168-7and4188-7) ................................................... 37

7. STITCH-TO-ANGLE TABLE BY GAUGE(PITCH AND mm CONVERSION TABLE) .. 398. GAUGE SETS ............................................................................................................... 409. TROUBLES AND CORRECTIVE MEASURES ............................................................ 45

–�–

1. SPECIFICATIONS

Modelname

Appl�cat�on

HookThreadtr�mmerSeparatelydr�venneedlebarmechan�smMax.sew�ngspeedNeedleGauges�ze

L�ftofpresserfootLubr�cat�onNo�se

LH-4�28

Forl�ght-andmed�um-we�ght

mater�als

SmallhookNotprov�ded

Notprov�ded

4,000rpm*

�/8"to�-�/2"3.2to38.�mm

Workplace-relatedno�seatsew�ng

speedn=4,000m�n–�:Lpa≦84dB(A)

No�semeasurement

accord�ngtoDIN45635-48-A-�.

LH-4�28-7(w�thautomat�cthreadtr�mmer)

Forl�ght-,med�um-andheavy-we�ght

mater�als

SmallhookProv�ded

Notprov�ded

4,000rpm*

5/32"to�-�/4"4to3�.8mm



No�semeasurement


LH-4�68-7(w�thautomat�cthreadtr�mmer�ncorporat�ng

cornerst�tch�ng)Forl�ght-,med�um-andheavy-we�ght

mater�als

SmallhookProv�ded

Prov�ded

3,200rpm

5/32"to�"4to25.4mm



No�semeasurement


Stype:standard,Ftype:foundat�on,Gtype:jeans

DPx5#9to#�6(ForStype),DPx5#9to#��(ForFtype),DPx5#�6to#22(Gtype)

�2mmbykneel�fter,5.5mmbyhandl�fterlever,9mmbykneel�fterw�thw�per

NewDefr�xO�lNo.�

*3,500rpmwhenthest�tchlengthexceeds4mm.

LH-4�88-7(w�thautomat�cthreadtr�mmer�ncorporat�ng

cornerst�tch�ng)Formed�um-and

heavy-we�ghtmater�als

LargehookProv�ded

Prov�ded

3,200rpm

5/32"to�"4to25.4mm



No�semeasurement


–2–

2. NAME OF EACH COMPONENT

1 Separatelydr�venneedlechangeoversw�tch

2 Threadtake-upcover3 F�ngerguard4 Threadtens�oncontroller5 Controlbox

6 Pedal7 Kneel�fterlever8 Powersw�tch9 Handsw�tch!0 Operat�onpanel

!1 Bobb�nw�nder!2 Threadstand!3 O�lsupplyopen�ng!4 Reversefeedcontrollever!5 Handl�fterlever

!2

!3

!4

8

6

7

5

!0

!1

9 1

4

3

2

!5

–3–

3. INSTALLATION

3-1. Installing the bottom cover

�) Thebottomcovershouldrestonthefourcornersofthemach�netablegroove.

23.5 mm 19.5 mm

4) F�th�nge6tothemach�nema�nbodyw�thscrews.

F�tthemach�neheadtotablerubberh�nges7andplace�tonheadcush�ons8onthefourcorners.

2) F�xtwoheadsupportrubberseats1onthefronts�deAtotheprotrud�ngsect�onofthemach�netableus�ngna�ls2.F�xtwomach�neheadcush�onseats3onh�nges�deBus�ngarubber-basedadhes�ve,Thenplacebottomcover4 on the fixed seats.

3) Removea�rventcap5attachedtothemach�nebed.(Besuretoattachcap5whentransport�ngthemach�nehead�nthestatethatthemach�nehead�sremovedfromthemach�netable.)

5) IncasetheAK-dev�ce�snotprov�ded,attachheadsupportrod9tothemach�netable.

If the sewing machine is operated without removing air vent cap 5, oil leakage from gear box portion C may occur.

1

3

1

3

5C

6

679

4

8

7

1

2

4

3

A B

–4–

3-3. Adjusting the height of the knee lifter

�) Thestandardhe�ghtofthepresserfootl�ftedus�ngthekneel�fter�s�2mm.

2) Youcanadjustthepresserfootl�ftupto�3mmus�ngkneel�fteradjustscrew1.

D o n o t o p e r a t e t h e s e w i n g machine in the state that the presser foot 3 is lifted by 12 mm or more since the needle bar 2 comes in contact with the presser foot 3.

WARNING :Turn OFF the power before starting the work so as to prevent accidents caused by abrupt start of the sewing machine.

3-2. Opening and closing of the control box (SC-910)

Whenopen�ngandclos�ngthecontrolbox,movethe knee l�fter components2 to the pos�t�onwherescrewhole1canbeobservedandperformthework.Fortheconnect�onofthecordsandsett�ngofthecontrol box, refer to the Instruct�on Manual forSC-9�0togetherw�thth�sInstruct�onManual.

1

2

1

2

3

–5–

3-4. Installation of thread stand

Assemblethethreadstand,set �tuponthemach�netableus�ngthe �nstallat�onhole �n thetableandt�ghtennut1gently.Whenyouusepowersuppl�edbytheoverheadpowerl�ne,passthepowersupplycordthroughhollowspoolrestrod2.

1

3-5. Caution when installing the panel

Usewashers, toothed lockwashers, and screws1mountedonthemach�neheadwhen �nstall�ngthepanel.

The screws attached to the panel may damage the screw holes since the pitch of the screws is different from that of the machine head.

1

2

–6–

4) Connect�4Pcode1com�ngfromthemach�neheadtoconnector7(CN46).

5) Connect4Pconnectorcom�ngfromthemach�nehead笘toconnector笨(CN3�).

6) Connect4Pconnector笳(saftysw�tchconnector)com�ngfromthemach�neheadtoconnector笶(CN48).

7) Connect7Pconnector笆com�ngfromthemach�neheadtoconnector筐(CN30).

8) Connectconnector笙com�ngfromthemach�neheadtoconnector筺(CN38,CN39).(Connect8PconnectortoCN38and�ncaseof9Pconnector,connecttoCN39.)

9) Whentheopt�onalAK�25dev�ce�sattached,connect2Pconnector筴com�ngfromtheAKdev�cetoconnector筧(CN40).

Be sure to securely insert the respect ive connectors af ter checking the inserting directions since all connectors have the inserting directions. (When using a type with lock, insert the connectors until they go to the lock.)

The sewing machine is not actuated unless the connectors are inserted properly. In addition, not only the problem of error warning or the like occurs, but also the sewing machine and the control box are damaged.

�) Passthecords笊ofthethreadtr�mm�ngsoleno�d,reverse-st�tch�ngsoleno�d,etc.,andthecordsofthesynchron�zer笆 ,safetysw�tch笳 ,mach�nehead4Pconnector笘 ,motors�gnal笙 ,motoroutput笞 throughholeA�nthetabletoroutethemdownunderthemach�netable.

2) Loosensetscrew!2�nfrontcover!5.3) Press�ngthes�deoffrontcover!5�nthe

d�rect�onofthearrow,openthefrontcovertowardyou.

Be sure to open / close the front cover with your hands.!5

!2

(1) LH-4128,4128-7,4168-7,4188-7

5 2

1

4

36

A

3-6. Connecting the cord

5

4

9

!0

!1

2

3

7

!9

@0

8

1

$5

–7–

6) Removesetscrew$0locatedontheleft-hands�deofthepowersw�tch,andplacethepo�ntofearthcord(asm.)$3com�ngfromkneel�fterdetect�ngsensorplate(asm.)$2tothesetscrew.Thent�ghtenthesetscrew.

When the earth cord has not been connected, malfunction will be caused.

7) Connectkneel�fterdetect�onsensorconnector$4toconnector$5(CN32).

Inadd�t�onto“3-6.(�)”,connectthecordsbelow.�) Passseparatelydr�venneedlechangeoversw�tchcord@1,separatelydr�venneedlesoleno�dcord

@2andseparatelydr�venneedlesensorcord@3throughholeA�nthetabletoroutethemdownunderthemach�netable.

2) Connect�0Pconnector@1com�ngfromthemach�neheadtoconnector@4(CN�25).3) Connect8Pconnector@2com�ngfromthemach�neheadtoconnector@5(CN�29).4) Connect6Pconnector@3com�ngfromthemach�neheadtoconnector@6(CN�28).5) Removethecordextend�ngfrom#2(COM)from#0(BNC)andconnect�tto#1(LH).

(2) 4168-7,4188-7

$2

$0$3

$4

#1

#2

@1

@2

@3

#0

@6

@5

@4

Optional unit A

–8–

[Connection of the connector for CP panel]Exclus�veconnectorsarepreparedforconnect�onoftheconnectorforCP-�60.Pay �ng at tent �on to the or �entat �on of theconnector, connect �t to connector笋 located onthe c�rcu�t board.After connect�ng, securely locktheconnector.[Connecting for IP panel]The connector for connect�ng IP-�00 and IP-��0areprepared.When connect�ng, �nsert the connector unt�l �t �slockedto筬 .

2) After �nsert�ng the connector, put all cordstogetherw�th cable cl�p band!3 locatedonthe s�de of thebox.At th�s t�me, bundle thecords (connector CN46) of thread tr�mm�ngsoleno�d, reverse feed soleno�d, etc.,AKcord(connectorCN40)andmotors�gnalcord(connectorCN39) to w�re saddle@5, bundledetector cord (connector CN30) above w�resaddle@5, knee l�fter detect�on sensor cord(connector CN32) between w�re saddles@5and@6andothercordstow�resaddle@6.

1. Fix the cord clamp and the cable clip band following the attaching procedure.

2. When removing the connector, remove it from the wire saddle and remove it while pressing the hook of the cable clip band.

�) F�xallcablescom�ngfromthemach�neheadw�thcablecl�pband絽attachedtot�e-mount綏 .

A

B

1. Fixthecableclipbandfollowingtheattachingprocedureasshowninthefigure. 2. To remove the cable clip band, push the cable clip band until it comes off while pressing

thehookofthebandfollowingtheremovingprocedureasshowninthefigure.

Howtofixcableclipband筍

Pull

How to remove cable clip band

Pushing the hook portion, push the band to remove it.

Pull PushPush Push the hook.

3-7. Managing the cord

!4

@3

@5

!3

@6

–9–

5) Connectmotoroutputcord笞toconnector筅locatedonthes�deofthebox.

6) Connectconnector4P筵ofthepowersw�tchtoconnector筥 .

Route the motor output cord from the front face of the box.

3) Closefrontcover筌wh�lepay�ngattent�ontop�nch�ngofthew�re.

L�ghtlypressport�on絽and�nsertfrontcover筌 w�th“cl�ck”.

4) After that, fix it with the screw笄 .

7) Makesurethatthepowersw�tch�sturnedOFFand�nsertpowersupplycord筰com�ngfromthepowersw�tch�ntothepowerplugsocket.(Illustrat�on�sforthejapanesespecification 100V type.)

1. Top end of power supply cord varies in accordance with destination or supply voltage. Check again the supply voltage and the voltage designated on the control box when installing the switch.

2. Prepare the power switch conformed to the safety standard.

3. Be sure to connect the ground wire (green / yellow).

笞

筅

筵

筥

筰

筌

絽

笄

–�0–

�) TurnONthepower.2) Presskneepadplate7andl�ftthepresser

footby5mmfromthetopsurfaceofthroatplate.

3) Turnkneel�fterdetect�onseat(asm.)4�nthedirection of the arrow and fix it at the position whereLEDofkneel�fterdetect�onsensor3startsl�ght�ngw�thsetscrew!3.Atth�st�me,al�gntheedgeofdetect�onseat(asm.)4w�ththatofkneel�fterdetect�onsensor3.

When the edges of knee lifter detection sensor 3 and knee lifter detection seat (asm.) 4 are not aligned, detection trouble will be caused.

4) Confirm that LED goes out when knee pad plate7�sreleased.

It is adjusted so that the knee lifting motion is detected when presser foot is lifted by 5 mm. When using it with the lift amount of less than 5 mm, reduce the standard adjustment value and re-adjust according to step 3).

5) Whenthemagnetofkneel�fterdetect�onseat(asm.)4comesnearthedetect�onsect�on(+marksect�on)ofkneel�fterdetect�onsensor3,�tdetectsthatkneel�ft�nghasbeenperformedandLEDl�ghtsup.

3-8. Adjusting the knee lifter detection seat (asm.)

4!3

7

3

4

3

3

To align edges

Conditions : LED starts lighting at presser foot lift of 5 mm. LED

Detection section

Magnet LED

* For explanation, the figure above omits knee pad plate and the like.

–��–

• 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 3,000 rpm or less.

• For the oil for hook lubrication, purchase JUKI New Defrix Oil No. 1 (Part No. : MDFRX1600C0).

• Do not use again the oil gathered in the bottom cover since it will cause the trouble of lubrication.

F�ll theo�l tankw�tho�l forhooklubr�cat�onbeforeoperat�ngthesew�ngmach�ne.�) Removeo�l hole cap1 and f�ll the o�l tank

w�thJUKINewDefr�xO�lNo.�us�ngtheo�lersuppl�edw�ththemach�ne.

2) F�ll the o�l tankw�th the o�l unt�l the top endof o�l amount �nd�cat�ng rod3 al�gnsw�ththeupperengravedmarker l�neof o�l amont�nd�cat�ngw�ndow2.

If the oil is filled excessively, it will leak from the a�r vent hole �n the o�l tankor properlubr�cat�on w�ll be not performed.So, becareful.

3) When you operate the sewing machine, refill o�l �f the topendofo�lamount �nd�cat�ng rod3comesdowntothelowerengravedmarkerl�neofo�lamount�nd�cat�ngw�ndow2.

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. Topreventtheoccurrenceofaninflammationorrash,immediatelywashtherelatedportionsif

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

2

1

Upper engraved marker line

Lower engraved marker line

4. PREPARATION OF THE SEWING MACHINE

4-1. Lubrication

–�2–

Per�od�cally clean f�lter sect�ons4 and5 (2places)(approx�matelyonce�nthreemonths).�) Loosensetscrews7ofo�ltubeholder6

and remove and remove the filter from the mach�nebed.

2) Loosenp�pestopper8,andremovetube9andjo�nt!0.

3) Afterremov�ngdustadheredtothenetsect�onofjo�nt!0, return the filter to its home position.

Whenthefiltersclogwithdustorthe like, trouble of lubrication occurs and trouble of the sewing machine will be caused.

4-2.Cleaningthefilter

89

7

6

8

!0 !0

9

Lubrication to hook

4

5Circulation

Lubrication

–�3–

4-3. Adjusting the amount of oil in the hook

Adjusttheamounto�lus�ngadjust�ngscrew1.Turnscrew1clockw�seto�ncreasetheamountofo�lin the hook or counterclockwise to decrease it. Measure the amount of oil in five seconds. When the amountofo�l�sexcess�velydecreased,break-downw�llbecaused.So,becareful.

4-4. Attaching the needles

Oil splashes

Oil amount decreases

Oil amount increases

LH-4168-7, 4188-7


LH-4128, 4128-7

Sw�tch"off"themotor.UseDPx5needles.�) Turnthehandwheelunt�ltheneedlebarhas

comeuptotheh�ghestpo�ntof�tsstroke.2) Loosenneedleclampscrews2andp�ckup

twoneedles1�nthewaythatthe�rgrooves3arefac�ngoutwards.

3) Inserttheneedles�ntotheneedleclampasfarastheyw�llgo.

4) T�ghtenneedleclampscrews2 firmly.


1

2

3

2

1

31

22

1

1

–�4–

4-5. How to take out the bobbin case

�) L�ftlatch1andtakeoutthebobb�ncaseandthebobb�ntogether.

2) Hold the bobb�n case by latch ra�sed, put�t �nto the shaft �n the hook correctly andreleasethelatch.

4-6. Inserting a bobbin in a bobbin case

[LH-4168-7 and 4188-7]�) Set abobb�n to thebobb�n case so that the

bobb�nturns�nthed�rect�onofarrowmarkA.2) Pass the thread through threadsl�t1 �n the

bobb�n case and draw the thread and pullthethreadsothat�tpassesunderthetens�onspr�ng.

3) Pass thread through another thread sl�t2then, pass �t through thread sl�t3 on thebobb�ncasefromthe�ns�de.

4) Put the thread on bobb�n threads slackpreventerspr�ng4.


LH-4128, 4128-7

LH-4168-7, 4188-7

[LH-4128 and 4128-7]�) Setabobb�ntothebobb�ncasesothatthe

bobb�nturns�nthed�rect�onofarrowmarkA.2) Passthethreadthroughthreadsl�t1�nthe

hookanddrawthethreadandpull�tsothat�tpassesunderthetens�onspr�ng.

A

A

1

2

4

3

1

1

–�5–

4-7. Threading the machine head

Thread the machine head following the order as illustrated in the figure.Passtheleft-handneedlethread,towardthemach�nehead,�ntheorderof1to!5.Passther�ght-handneedlethread�ntheorderofAtoP.

Be careful of threading of needle clamp thread guides (!4, O). FigureAforthinfilamentthreadof#60orless FigureBforthickfilamentthreadandpolyesterspunthreadof#50ormore


Intermediate thread guide

Fig A Fig B LH-4188-7

!1-L

!2-M

!3-N

!4

K

!0

O

P

A1

2

B

!5

43

D

C

G

9

E

H

6

7

J

8 -I

5F

LH-4188-7

–�6–

�) Strokeofthreadtake-upspr�ng1onther�ght�sadjustablebymov�ngthreadtens�onNo.2asm.3totheleftorr�ghtafterloosen�ngthreadtens�onNo.2setscrew2.

2) Strokeofthreadtake-upspr�ng4ontheleft�sadjustablebymov�ngthreadtens�onNo.2asm.6totheleftorr�ghtafterloosen�ngthreadtens�onNo.2setscrew5.

3) Movethreadtens�onNo.2asm.3and6tother�ghtto�ncreaseortothelefttodecreasethestrokeofthethreadtake-upspr�ng.

When adjusting the stroke of thread take-up springs 1 and 4, thread release pins 7 and 8 should 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.

4-9. Thread take-up spring

(1) When you want to change the stroke of the thread take-up spring


To turn

�) Needlethreadtens�on Turnthreadtens�onnutNo.21clockw�seto

�ncreaseorcounterclockw�setoreducetheneedlethreadtens�on.

4-8. Thread tension

2) Bobb�nthreadtens�on Turntens�onadjust�ngscrew2clockw�seto

�ncreaseorcounterclockw�setoreducethebobb�nthreadtens�on.

1

2

7

8

9

!1

!2

!0

2

3

4

6

15

–�7–

(2) When you want to change the tension of the thread take-up spring

�) Tens�onofthreadtake-upspr�ng1onther�ght�sadjustablebyturn�ngspr�ngstud!3tother�ghtto�ncreaseortothelefttoreduce.

2) Tens�onofthreadtake-upspr�ng4ontheleft�sadjustablebyturn�ngspr�ngstud!4tother�ghtto�ncreaseortothelefttoreduce.

Turn st�tch d�al1 counterclockw�se (clockw�se)to set the value on the d�al correspond�ng to ades�redst�tchlengthtothemarkerdot3engravedonthemach�nearm.When �t �shard to turnst�tchd�al1, turn �twh�lesl�ghtlydepress�ngreversefeedcontrollever2.

• Reverse feed operation�) Depressreversefeedcontrollever2.2) Reversest�tchesaremadeaslongasyou

keepdepress�ngthelever.3) Releaselever,andthemach�new�llrunforward.

4-10. Adjusting the stitch length

1

2

3

!3

!4 1

4

–�8–

1. When winding the bobbin thread, start the winding in the state that the thread between the bobbin and thread tension disk 7 is tense.

2. When winding the bobbin thread in the state that sewing is not performed, remove the needle thread from the thread path of thread take-up and remove the bobbin from the hook.

3. There is the possibility that the thread pulled out from the thread stand is loosenedduetotheinfluence(direction)ofthewindandmaybeentangledinthehandwheel. Be careful of the direction of the wind.

6) In case that the bobb�n thread �s notwoundevenlyon thebobb�n, loosen thenut6andturn the bobb�n thread tens�on to adjust thehe�ghtofthethreadtens�ond�sk7.

• It�sthestandardthatthecenterofthebobb�n�sash�ghasthecenterofthethreadtens�ond�sk.

• Move the pos�t�on of the thread tens�ond�sk7 to thed�rect�onofDasshown �n thef�gure on the left when the w�nd�ng amountof thebobb�nthreadonthe lowerpartof thebobb�n �sexcess�veandtothed�rect�onofEas shown �n the f�gure on the left when thew�nd�ngamount of the bobb�n threadon theupperpartofthebobb�n�sexcess�ve.

Aftertheadjustment,t�ghtenthenut6.7) Toadjustthetens�onofthebobb�nw�nder,

turnthethreadtens�onnut8.

D

E

7

7

7

6

8

�) Insertthebobb�ndeep�ntothebobb�nw�ndersp�ndle1unt�l�tw�llgonofurther.

2) Pass the bobb�n thread pulled out from thethread tens�oncontroller locatedon the r�ghts�deof the thread stand as shown �n thef�gureand w�nd clockw�se the end of thebobb�nthreadonthebobb�nseveralt�mes.

(Incaseofthealum�numbobb�n,afterw�nd�ngclockw�setheendofthebobb�nthread,w�ndcounterclockw�sethethreadcom�ngfromthebobb�n thread tens�on several t�mes to w�ndthebobb�nthreadw�thease.)

3) Press the bobb�n w�nder tr�p latch2 �n thed�rect�onofAand start the sew�ngmach�ne.Thebobb�n rotates �n thed�rect�onofCandthe bobb�n thread �s wound up.The bobb�nw�nder sp�ndle1 automat�cally as soonasthe winding is finished.

4) Removethebobb�nandcutthebobb�nthreadw�ththethreadcutreta�ner3.

5) Toadjust thew�nd�ngamountof thebobb�nthread, loosensetscrew4andmovebobb�nw�nder tr�p latch2 to thed�rect�onofAorB.Thent�ghtensetscrew4.

Tothed�rect�onofA:Decrease Tothed�rect�onofB:Increase

4-11. Winding the bobbin thread

B

A

3

12

4

C

–�9–

(2) Lower stop position�) TheDOWNneedlestoppos�t�onwhenthepedal

�sreturnedtotheneutralpos�t�onafterthefrontpartofthepedal�sdepressed�sbetweenthepos�t�onwheretheneedlep�ercesthefeeddogandtheupperendofneedleeyeletal�gnsthetopsurfaceoffeeddogandthatwhereneedles�nksby3mm.

2) ThesameasUPstop,stopneedle2�nDOWNpos�t�on,turnOFFthepower,andloosenscrew3toperformadjustmentw�th�ntheslotofthescrew.Theneedlestopt�m�ng�sadvanced�fyoumovethescrew�nthed�rect�onofE,andthet�m�ng�sdelayed�fyoumovethescrew�nthed�rect�onofF.

Do not operate the machine with screw 3 loosened. Just loosen the screw, and do not remove it.

(1) Stop position after thread trimming �) Thestandardneedlestoppos�t�on�sobta�ned

byal�gn�ngmarkerdotAonthepulleycoverw�thwh�temarkerdotBonthehandwheel.

2) Stoptheneedle�nUPpos�t�on,turnOFFthepower,andloosenscrew3toperformadjustmentw�th�ntheslotofthescrew.Theneedlestopt�m�ng�sadvanced�fyoumovethescrew�nthed�rect�onofC.

Theneedlestopt�m�ng�sdelayed�fyoumovethescrew�nthed�rect�onofD.

Do not operate the machine with screw 1 loosened. Just loosen the screw, and do not remove it.

4-12. Adjusting the needle stop position


AB

C

D

1

Top surface of feed dog

0 ~ 3 mm

2 3

E

F

–20–

(1) Adjusting the pressure required to depress the front part of the pedal

�) Th�s pressure can be adjusted by alter�ngthe pos�t�on of lever4 of pedal�ng pressureadjustspr�ng1.

2) Thepressure decreases when you hook thespr�ngonthelefts�de.

3) Thepressure �ncreaseswhen you hook thespr�ngonther�ghts�de.

(2) Adjusting the pressure required to depress the back part of the pedal

�) Th�spressurecanbeadjustedus�ngregulaterscrew2.

2) The pressure �ncreases as you turn theregulatorscrew�n.

3) The pressure decreases as you turn thescrewout.

(3) Adjusting the pedal stroke �) Thepedalstrokedecreaseswhenyou �nsert

connect�ng rod5 �nto the left hole3.(Bothdepress�ngandreturn�ngofthepedalbecomeheavy.)

4-13. Pedal pressure and pedal stroke

(1) Installing the connecting rod�) Movepedal3tother�ghtorleftas�llustrated

bythearrowssothatmotorcontrollever1andconnect�ngrod2arestra�ghtened.

(2) Adjusting the pedal angle�) Thepedalt�ltcanbefreelyadjustedby

chang�ngthelengthoftheconnect�ngrod.2) Loosenadjustscrew4,andadjustthelength

ofconnect�ngrod2.

4-14. Adjustment of the pedal


1

2

5

3

4

1

2

4

3

2

–2�–

The pedal is operated in the following four steps: �) Themach�nerunsatlowsew�ngspeedwhen

youl�ghtlydepressthefrontpartofthepedal.B

2) Themach�nerunsath�ghsew�ngspeedwhenyoufurtherdepressthefrontpartofthepedal.A

(Iftheautomat�creversefeedst�teh�nghasbeenpreset,themach�nerunsath�ghspeedafter�tcompletesreversefeedst�tch�ng.)

3) Themach�nestops(w�th�tsneedleupordown)whenyouresetthepedalto�tsor�g�nalpos�t�on.C

4) Themach�netr�msthreadswhenyoufullydepressthebackpartofthepedal.E

* Whenauto-l�fter(AK�25)�sused,�-stepsw�tch�s�ncreasedbetweenstopandthreadtr�mm�ng.Thepresserfootgoesupwhenthebackpartofthepedal�sl�ghtlydepressedD,andthepresserfootcomesdownoncewhenthebackpartofthepedal�sfurtherstronglydepressed.

Thenthethreadtr�mmer�sactuatedandthepresserfootgoesupaga�n.

• Ifyouresetthepedalto�tsneutralpos�t�ondur�ngtheautomat�creversefeedst�tch�ngatseamstart,themach�nestopsafter�tcornpletesthereversefeedst�tch�ng.

• Themach�new�llperformnormalthreadtr�mm�ngeven�fyoudepressthebackpartofthepedal�mmed�atelyfollow�ngh�ghorlowspeedsew�ng.

• Themach�new�llcompletelyperforrnthreadtr�mm�ngeven�fyouresetthepedalto�tsneutralpos�t�on�mmed�atelyafterthemach�nestartedthreadtr�mm�ngact�on.

• Whentheauto-l�fter(AK�25)�snotused,andtheselect�onofpedaltypeofthecontrolbox(SC-9�0)�ssettoKFL,thepedaldepress�ngamountatthet�meofthreadtr�mm�ngcanbeshallowed.Forthesett�ngprocedure,refertotheInstruct�onManualforSC-9�0.

[When the table/stand for standing work is used] Whenus�ngthetable/standforstand�ngwork,changethedescr�pt�onofthefunct�onsett�ngNo.

��7from“0”to�s�ncethepresser�sl�ftedbymeansofthepresserl�ft�ngpedal. In this case, the simplified teaching function cannot be used for LH-4168-7, 4188-7.

5. OPARATION OF THE SEWING MACHINE

5-1. Pedal operation

A

B

C

D

E

–22–

�) When you want to keep the presser foot�n the l�fted pos�t�on, turn hand l�fter1 �nthe d�rect�on of the arrow. By so do�ng, thepresserfootr�se5.5mm.

2) When you want to lower the presser foot,lower the hand l�fter.Th�s w�ll return thepresser foot to �ts predeterm�nded lowerpos�t�on.

3) Operate the knee l�fter, and the presserw�llr�sebyapprox�mately�2mm.

Do not perform thread trimming operation with the presser foot lifted since there is a case where the wiper comes in contact with the presser foot.

5-2. Hand lifter

Loosen nut2 by turn�ng counterclockw�se, andturnpresser spr�ng regulator1 to adjust thepressure.Turntheregulatorclockw�seto�ncreasethe pressure and turn �t counterclockw�se todecreasethepressure.Aftertheadjustment,t�ghtennut2.

5-3. Adjusting the pressure of the presser foot

Decrease

1

2

To turn

1

Increase

–23–

For LH-4�28-7, LH-4�68-7, LH-4�88-7 the kneel�fter orAK dev�ce �s not �nterlocked w�th thethreadtens�onreleaseofthreadtens�oncontrolleratthet�meofdel�very.Whenreleas�ngthethreadtens�on,presslever1tor�sethed�sks.

5-4. Thread tension release changeover when using the knee lifter

When�nterlock�ngthethreadtens�onreleaseRemove the cap at the back, pass screw2suppl�ed as accessor�es through the hole �npresser l�fter plate3, and f�x �t to presser l�fterleverA4.

When inter locking the thread tension release :

1. Thread slacks when turning cloth at the corner stitching, and sewing trouble of thread tension release may occur .

2. When the wiper is not used at the time of thread trimming, needle thread may be drawn out when removing cloth.

1

3

4

2

2

–24–

1 Left-handneedlechangeoversw�tch Whenth�ssw�tch�spressed,left-handneedle

goesup.When�t�spressedaga�n,theneedlecomesdown.

2 R�ght-handneedlechangeoversw�tch Whenth�ssw�tch�spressed,r�ght-hand

needlegoesup.When�t�spressedaga�n,theneedlecomesdown.

3 Teach�ngsw�tch

When1 or2 �s pressed after press�ng3, or3 �s pressed after press�ng1 or2, numberofst�tchesunt�lthepresserfootgoesupnextfromas�ngleneedlestate �scounted.Whenthepresserfoot �s lowered, the needle returnsafter sew�ngthenumberofst�tcheswh�chhasbeencounted.

5-5. Separately driven needle changeover switch (for LH-4168-7 and 4188-7)

• Changeover of the teaching modeChangeover of the teach�ng mode can be performedby the proceduresbelow. Use �t properly �naccordancew�ththetypesofsew�ngproducts.�) Press�ngthebuttonlocated�ntheextremer�ghts�deofthecontrolbox,turnONthepowersw�tch,

andthesett�ngforfunct�oncanbecalled. (Refer to the Instruction Manual for SC-910.)2) Callfunct�onsett�ngNo.��2ofthed�splay�nthecontrolbox.

Setting 0 (Initial set value) : Normal mode (manual teaching mode)When the sew�ng comes to the corner sect�on, press left-hand (r�ght-hand) needle changeoversw�tchandteach�ngsw�tch.Sewthecorner �nas�ngleneedlestate, l�ft thepresser foot, turn thecloth,andsewthecornerofreturn.It�snotnecessaryfortheoperatortoperformthereleaseatthet�meofreturns�ncethereleaseofs�ngleneedleafterth�swork�sautomat�callyperformed.(Th�sfunct�oncannotbeobta�nedunlesstheteach�ngsw�tch�spressed.)

Setting 1 : Automatic move by changeover of single needleIt �s the sett�ng that the teach�ng mode �s automat�cally setwhen the separately dr�ven needlechangeoversw�tch�spressed.W�thoutpress�ngtheteach�ngsw�tch,numberofst�tchesunt�lthepresserfootgoesupfromas�ngleneedlestate�scounted,andwhenthepresserfoot�slowered,theneedlereturnsafterthenumberof st�tcheswh�chhasbeen counted.Numberof t�mesof button operat�on �s decreaseds�nce thenumberofst�tchesofenter�ngandthatofreturnarethesame�nmanycases.

Setting 2 : Teaching mode changeover prohibitionIt �sthesett�ngthatthemodedoesnotbecometheteach�ngmodeevenwhentheteach�ngsw�tch�spressedafter theseparatelydr�venneedlechangeoversw�tchwaspressedandseveralst�tchesweresewn.Th�sfunct�onsavesthetroublethatthest�tchesofenter�ngandreturndonotagreew�theachotherwhentheteach�ngsw�tchworksafterseveralst�tchesweresewn.

Separately driven needle changeover switches

1

2 3

–25–

�) Preparethegaugeforbottomfeed.Temporarily set needle rocking rod fixing base1conta�ned�ntheaccessor�estohole2ofthemach�neframew�thwashers3andsetscrews4.

(1) How to use�) Depresssw�tch1,andthemach�new�ll

�mmed�atelyrun�nthereversed�rect�on.2) Reversest�tch�smadeaslongasyoukeep

depress�ngthesw�tchlever.3) Releasethesw�tchleverforforwatdsew�ng.

5-6. One-touch reverse feed switch lever (for touch-back)

6. MAINTENANCE

6-1. Changing procedure to bottom feed and the adjustment (LH-4128 without thread trimmer only)

1

1

2

34

–26–

2) Loosen nut5 after adjust�ng the feed d�alto “0”,moveneedlebar rock�ng rod6 fromneedle bar rock�ng rod arm7 to needlerocking rod fixing base 1, and fix it with nut 5.

3) After replac�ng the feed dog and the throatplate w�th the components for bottom feed,adjust the position of needle rocking rod fixing base1sothattheneedlecenteral�gnsw�thneedle holes8 �n throat plate9, and f�xsetscrews4 wh�ch have been temporar�lyset.

4) Loosensetscrews!2(2places)�nsprocket!0.Atth�st�me,removethesetscrewwh�ch�slocated�nthesamed�rect�onofengravedmarkerl�ne!1oftheneedlebarrock�ngrod.

Turn the pulley by 180˚ without turning the hookdr�v�ngshaft!3,andal�gnengravedmarkerdot!4onhookdr�v�ngshaft!3w�thengravedmarkerl�ne!1.

Putthesetscrewwh�chhasbeenremovedtothe screw hole on the opposite side, and fix w�thsetscrews!2(2places).

5

1

6

5

1

!2

!3

!0

!4

!1

9

8

Needle

7

–27–

The procedure �s the reverse of “6-�. Chang�ngproceduretothebottomfeed”.Loosen nut5, move needle bar rock�ng rod6from needle rocking rod fixing base 1 to needlebarrock�ngrodarm7, and temporarily fix it with nut5.Atth�st�me,al�gntheengravedmarkerl�neof7w�ththatof8.Replacethefeeddogandthethroatplatew�ththecomponentsforneedlefeed.

Next, adjust so that the needle comes to thecenterofneedleholeoffeeddog�nbothcasesofp�erc�ngofneedleanddraw�ngofneedle.For adjustment, loosen nut5 , move needlerock�ngadjustmentscrew8�nthed�rect�onofthearrow,andsecurelyt�ghtennut5.

6-2. Changing procedure to needle feed (for LH-4128 only)

Loosensetscrew!2�nsprocket!0,turnthepulleyby 180˚, align engraved marker dot !4onhookdr�v�ngshaft!3w�thengravedmarkerl�ne!1,andfix it with setscrew !2.

Move the setscrew which is located in the same direction of the engraved marker line to the screw hole on the opposite side.

!2

!3

!0

!4

!1

5

1

6

7

5

1

Engraved marker line

7

6

8

–28–

6-3. Adjusting the inner hook guide

[LH-4128, 4128-7 and 4168-7]�) Standardadjustment valueof the open�ng

of the �nner hook stopper �s 0.3 mm.Adjustthehandwheeltoengravedmarkers3�nthecenter of three engraved markers, make the�nnerhookgu�de1come�ncontactw�ththe�nner hookwh�le press�ng the cl�ck of �nnerhook �n the d�rect�on of the arrow to f�x the�nnerhookgu�de.

When the �nner hook gu�de1 �s f�xed atthe pos�t�on of small engravedmarker2,the open�ng of the �nner hook stopper �sdecreased, and when it is fixed at the position of largeengravedmarker4, theopen�ngofthe�nnerhookstopper�s�ncreased.

4

3

2

1

WARNING :Turn OFF the power switch and ascertain that the motor totally stopped before starting the work so as to prevent personal damage caused by abrupt start of the sewing machine.

LH-4128, 4128-7, 4168-7

LH-4188-7 [LH-4188-7]�) Turn the handwheel �n the normal d�rect�on

unt � l �nner hook gu �de1 has ent � re lyw�thdrawnfrom�tswork�ngpos�t�on.

2) Turnbobb�ncase2 �nthed�rect�onofarrowmarkunt�l �nnerhookstopper3 rests �n thegrooveonthroatplate4.

3) Loosen setscrew5 �n the �nner hookgu�deand prov�de a clearanceof 0.3 to 0.4mmbetweenthe�nnerhookgu�deandprotrus�onAonthebobb�ncase.1

24

3

A

5

0.3 to 0.4 mm

–29–

�) Determ�nethehe�ghtofneedle.�. Setthest�tchd�alto2.5onthescale.2. Turnthehandwheeltobr�ngtheneedlebarto

thelowestpos�t�on.3. Remove cap1 , loosen setscrews2 �n

needledr�vearms3,adjustengravedmarkerl �nes5 -A wh�ch are the fourth from thebottom of needle bars4 to the bottom endof needlebar lowerbush�ng6, and t�ghtenneedledr�ve arms3 w�th screw t�ghten�ngto rque o f 5 .9 Nm (60 kg f cm) us �ngsetscrews2.

4. Turn the handwheel and adjust engravedmarker l�nes5-B wh�ch are the th�rd fromthebottomoftheneedlebartothebottomofneedlebarlowerbush�ng6.(2.2mmup)Atth�s t�me, �t �s thestandard that thed�stancefrom the topendof theneedleeyelet to thebladepo�ntofthehook�s�.2mm.

The aforementioned adjustment is applied to the case when DPX5 needle is used. When using DPX17 needle, adjust with 5-C and 5-D respectively.

When loosening/tightening setscrew 2, perform the work so that needle drive arm 3 does not move in the lateral direction. When it moves, needle bar torque or needle bar seizure will be caused.

5. Iftheneedle-to-hookrelat�on�sd�fferentfromthe aforement�oned standard adjustment,remove needle clamp screw8 and turnneedleclamp7byonerevolut�on(theextentofadjustment:0.6mm).Theneedle-to-hookrelat�on can also be adjusted by remov�ngscrew!0fromthespr�ngshoeandturn�ng

spr�ngshoe9byahalfrevolut�on(theextentofadjustment:0.3mm).

[ LH-4168-7, 4188-7 ]

6-4. Needle-to-hook relation

4

3

5-A5-B

6

5-C5-D

1

2

!0

7

8

9 1.2

mm

2.2

mm

–30–

2) Determ�nethepos�t�onofthehook.�. Loosenthreesetscrews8�nthescrewgear

(small).2. Inth�sstate,loosenfoursetscrews!1�n

hookdr�v�ngshaftsaddle!0,andmovehookdr�v�ngshaftsaddle!0tother�ghtorlefttoadjustsothataclearanceof0.0�to0.05mm�sprov�dedbetweenbladepo�nt7ofthehookandneedle9.Thent�ghtensetscrews!1.

3. Inthestatedescr�bed�nstep�)-4.,al�gnbladepo�nt7ofthehookw�ththecenteroftheneedleandt�ghtensetscrews8�nthescrewgear(small).

0.01 to 0.05 mm

8

!0

!1

!1

9

7

7

9

[Reference dimension] Needle clamp height at needle bar lower dead point

LH-4�28,4�28-7

D�mens�onA

LH-4�68-7 LH-4�88-7

�5.�±0.�5mm �5.8±0.�5mm �5.2±0.�5mm

A A

Throat plate installing plane

Throat plate installing plane

LH-4128,4128-7,4168-7 LH-4188-7

–3�–

[ LH-4128, LH-4128-7 ]

�) Determ�netheneedlebarhe�ght.�. Setthest�tchd�alto2.5onthescale.2. Turn the handwheel to br�ng the needlebar to the lowest pos�t�on.Then, loosenneedlebar

connect�ngstudclamp�ngscrew1.3. Adjustengravedmarkerl�neAwh�ch�sthesecondfromthebottomofneedlebar2tothebottom

endofneedlebarrock�ngbase3,andt�ghtentheneedlebarconnect�ngstudclamp�ngscrew.4. Turnthehandwheelandadjustlowerengravedmarkerl�neBoftheneedlebartothebottom

endoftheneedlebarrock�ngbase.(2.2mmup)Atth�st�me,thed�stancefromthetopendoftheneedleeyelettothebladepo�ntofthehookbecomes�.2mm.

2) Determ�nethepos�t�onofthehook.�. Loosenthreesetscrews5 �nthescrewgear

(small).2. Inth�sstate,loosenfoursetscrews8�n

hookdr�v�ngshaftsaddle7,andmovehookdr�v�ngshaftsaddle7tother�ghtorlefttoadjustsothataclearanceof0.0�to0.05mm�sprov�dedbetweenbladepo�nt4ofthehookandneedle6.Thent�ghtensetscrews8.

3. In the state descr�bed �n step �)-4., al�gnbladepo�nt4of thehookw�th thecenterofthe needle and t�ghten setscrews5 �n thescrewgear(small).

0.01 to 0.05 mm

3

2

AB

1

5

7

8

8

6

4

6

4

1.2

mm

2.2

mm

–32–

(1) Adjusting the height�) Loosenbottomfeedl�nksetscrew1,andturn

feeddr�v�ngl�nkshaft2toadjustthehe�ght.Standardhe�ght�s�mmfromthethroatplate�ntheh�ghestpos�t�on.

6-5. Adjusting the height and the inclination of the feed dog

(2) Inclination�) Removecap4onthes�deofmach�nebed,

loosenfeedbarshaftsetscrew3,andturnknurledsect�on5toadjustthe�ncl�nat�on.Standardadjustment�sasfollows:

·LH-4�28,4�28-7,4�68-7:Pos�t�onwhereengravedmarkerdotCoffeedbararmal�gnsw�thengravedmarkerdotBoffeedbarshaft.(EngravedmarkerdotA�sforLH-3500.)

·LH-4�88-7:Engravedmarkerl�ne�slevel.

1mm

Confirm the grounding when replacing the presser foot.�) Whenchang�ngthehe�ghtortheangleat

thet�meofreplac�ngthepresserfoot,loosenneedlebarconnect�ngstudclamp�ngscrew1toadjust�t.(Makesureoftheclearancebetweentheholeofthepresserfootandtheneedleandthatbetweenthepresserfootandthethroatplate.)

2) Aftertheadjustment,securelyt�ghtenthescrew1.

6-6. Adjusting the presser foot

2

3

1

3

4

1

5

A

B

C

[LH-4128, 4128-7, 4168-7][LH-4188-7]

Level

–33–

3

2

14

6-9. Adjusting the thread presser spring

Insertarod(th�nrod,wrench,etc.) �ntoadjust�nghole2 �n thread presser spr�ng base1 , andloosensetscrew4w�thahexagonalwrenchkeyof�.5mm.Adjustthethreadpresserspr�ngbymov�ngrod3 in the direction of arrow mark A, and fix it with setscrew4.

Clamp trouble occurs even when the thread presser spring pressure is excessive or insufficient.So,becareful.

A

6-8. Lubricating route when changing the needle gauge size

When chang�ng the needle gauge s�ze, conf�rmthat there �snoproject�onofo�lp�peasshown�nthe figure, and correct the lubricating route to the hookshaftsaddle�fnecessary.Loosen screw1 and turn w�re2 to adjust thebendofthep�pe.

When the lubricating route is improper, it is feared that such troubles occur as insufficient lubrication caused by slip-off or breakage of the oil pipe, and seizure of the machine caused by oil leakage or insufficient lubrication by breakage of the oil pipe when the machine is tilted and the oil pipe is caught in the machine. So, be careful.

1

2

1

2

6-7. Move (adjustment) of the hook shaft saddle when replacing the gauge

Move of the hook shaft saddle when replac�ngthe gauge can be performed w�th ease by onlyloosen�ngscrews1and2.It�snotnecessarytore-adjustthehookt�m�ng.

–34–

6-10. Adjusting the position of the moving knife

�) Al�gncounterkn�febase1w�thplaneAofcounterkn�fe2.

2) Loosenclampscrew3located�ntherearofmach�nebedandadjustsothatd�stance2betweenthetopendofmov�ngkn�feBatthet�meofwa�t�ngandthetopendofcounterkn�fe4�sd�mens�onB.

D�mens�onB4�28-73.�±0.2mm4�68-73.3±0.2mm4�88-73.3±0.2mm

3) SetclearanceCbetweenmov�ngkn�fe3andthe�nnerhookto0.4±0.�mmwhenmov�ngkn�fe3works.

Loosenmov�ngkn�fesetscrews6and7andadjusttheclearance.

1

A

2

B

3

2

4

4

3

C

6

7

–35–

1

2

6-11. Replacing the bobbin thread slack preventer spring (for LH-4168-7 and 4188-7)

�) Loosenscrew1andremovebobb�nthreadslackpreventerspr�ng2fromthegrooveonthebobb�ncase.

2) F�tbobb�nthreadslackpreventerspr�ng2wh�chreplacestheremovedspr�ng�nthebobb�ncasethroughthegroove.

3) F�xbobb�nthreadslackpreventerspr�ng2�nthebobb�ncasebyt�ghtenscrew1.Atth�st�me,carefullychecktheoperat�ngrangeandtens�onorthespr�ng.

Groove

6-12. Adjusting the hook needle guard


When replacing the hook, confirm the position of the needle guard.Thestandardpos�t�on�sthestatethathookneedleguard2comes�ncontactw�ththes�deofneedle1andtheneedle�salongthehookneedleguardby0to0.�mm.Ifnot,adjustbybend�ngthehookneedleguard.�)Whenbend�ngthehookneedleguard�nward,performbyenter�ngascrewdr�vertotheouts�deof

thehookneedleguard.2)Whenbend�ngthehookneedleguardoutward,performbyenter�ngascrewdr�vertothe�ns�deof

thehookneedleguard.

(Bend inward.) (Bend outward.)

0 - 0.1 mm

1

2

22

–36–

When �nstall�ng thegauge us�ng the screwhole1�n the center of the bed sl�de, select the length ofthescrewsothatthetopendofthescrewdoesnotcome �n contactw�th the feedbar shaft2 locatedunderthebedsl�de.

When the top end of the screw interferes with the feed bar shaft, feed pitch becomes uneven, or the machine is locked. So, be careful.

(2) Relation between the angle of corners and stitch lengthToperformcornerst�tch�ngw�thaccuracy, thest�tchlength can be determ�ned referr�ng to the table ofthe numberof st�tches by gauges.However, checkwhether thest�tch lengthdeterm�nedreallymatchesthecornerbyactuallysew�ng�t.(Example) To sew a correr of 90˚ of angle using a

3/16" gauge with the stitch length specified to�.6mm, thenumberofst�chescanbeobta�ned �n the follow�ngway.Observe the"90˚" columns on the table of the number of st�tchesbyst�tchlengthgaugestosearchforthecolumn�nwh�ch"�.6"�s�nd�cated.Then,you can find "3" on the top of the "1.6" lines. Th�smeansthenumberofst�tches�s3.

6-13. Stop of the needle bars and angle of corners for corners stitching (for LH-4168-7 and 4188-7)

(1) Stop of the needle barsWhenseparatelydr�venneedlechangeoversw�tch1�spresseddur�ngsew�ng,theleft-handneedlebarstops,andwhen2 �spressed, the r�ght-handneedlebarstops.Whenthesew�ngmach�ne�sbe�ngoperatedath�ghspeed,thespeed�sautomat�callyreducedandtheneedlebar�sstopped.Whenseparatelydr�venneedlechangeoversw�tches1and2arepressedaga�n,themach�nereturnsto2-needlesew�ngmach�ne.The lampofsw�tchbecomesasdescr�bedbelow �naccordancew�th thestateofseparatelydr�venneedlechangeover.Atthet�meofneedledr�v�ng:L�ghtgoesoff.Atthet�meofwa�t�ngseparatelydr�venneedle changeover : Light flashes on and off.Atthet�meofneedlestop:L�ght�sturnedon.

(3/16" gauge)

3 stitches 3 stitches

90˚

6-14. Caution when installing the gauge to the bed slide

1

2

21

If sewingacornerofwhichangle is 40˚or less, the thread take-upamountof thebobbin threadslackpreventerspringwillbe insufficient. In thiscase, the threadwillremain on the wrong side of the material.

–37–

Whenthesew�ngmach�ne�susedforacerta�nnumberoft�mesofsew�ng(numberofst�tches),errorcodeNo.E220�sd�splayedonthecontrolboxwhenthepower�sturnedON(�t�sd�splayedonIPpanelaswellwhenus�ng IPpanelssuchas IP-�00, IP-��0,etc.),and further thewarn�ngbuzzersounds5times intermittently. This warning is to inform you of the replenishing time of grease to the specified places.Besure to replen�shgrease,callmemorysw�tchNo.��8,set thedescr�pt�on to “�”,and turnOFFthepower.Although the mach�ne can be used cont�nuously even after the d�splay of error No. E220, error No.E220 �sd�splayedevery t�me thepower �s turnedONand thewarn�ngbuzzersounds.PressRESETkeywhenus�ngIPpanelandtheerror�sreleased.Inadd�t�on,whenthesew�ngmach�ne�susedforacerta�nper�odoft�meafterthed�splayoferrorNo.E220,errorNo.E22��sd�splayed,andthesew�ngmach�nefa�lstooperate.ErrorcannotbereleasedevenwhenRESETkey�spressedwhenus�ngIPpanel.If error No. E221 is displayed, be sure to replenish grease to the specified place below, call memory sw�tchNo.��8,setthedescr�pt�onto“�”,andturnOFFthepower.

1. After replenishing grease, call memory switch No. 118, set the description to “1”, and turn OFF the power. Otherwise, error No. E220 or error No. E221 is displayed again.

2.Forreplenishinggreasetothespecifiedplacesbelow,useJUKIGREASEATUBE (Part No. 40006323) or JUKI GREASE B TUBE (Part No. 40013640) supplied asaccessories.Ifgreaseotherthanthespecifiedoneisused,breakageofcomponents will be caused.

6-16.Replenishinggreasetothespecifiedplaces(forLH-4168-7and4188-7)


�)Adjustengravedmarkerdot1onthemach�nearmtowh�teengravedmarkerdot2onthehandwheel(secondwh�teengravedmarkerdot�ntherotat�ngd�rect�onofthesew�ngmach�ne).

2)Moverod3�nthed�rect�onofthearrow,andadjustw�thtwoclamp�ngscrews5sothattheclearancebetweenthetopendofneedleandw�per4�sapprox�mately2mm.

Needle

4

5

3

2 mm

21

6-15. Position of the wiper

–38–

(2) Center link section

�) Removetherubbercaplocatedatthetopsurfaceoffacesect�onandthefaceplate.

2) F�lljo�nt1suppl�edasaccessor�esw�thgreaseBfromthegreasetube.

3) Connectp�pe3w�thn�pple,r�ght2,turnscrew4suppl�edasaccessor�estojo�nt1,and fill the joint with grease.

Replenish the joint with grease by repeatinggreasefillingofstep2)when thefirst replenishing isnotenough.

4) W�ththesameprocedureassteps2)and3),fill nipple, left 5w�thgreaseB.Atth�st�me,passthep�pethroughtherubbercapholelocatedatthetopsurfaceofthefacesect�on,andconnect�tw�thn�pple,left5.

5) Returnthefaceplate,rubbercap,andtopfacecovertothe�rhomeplaces.

Toconfirmtheamountofreplenishing at all grease replenishing sections is performedbyconfirmingthatgrease protrudes from the corresponding sections.

Do not loosen setscrews 7 in fulcrum shaft base 6. If it is removed once, seizure of sewing machine torque will be caused.

2

1

3

4

(1) Replenishing grease to the needle bar drive cam section

�) Removethetopfacecover,andremovetherubbercapsattachedtothen�pples1.

2) F�lljo�nt3suppl�edasaccessor�esw�thgreaseAfromthegreasetube.

3) Connectp�pe2w�thn�pples1,turnscrew4suppl�edasaccessor�estojo�nt3,andreplen�shthejo�ntw�thgrease.

Replenish the joint with grease by repeatinggreasefillingofstep2)when thefirst replenishing isnotenough.

4) F�ttherubbercapstothen�pples,turnthema�nshaft by hand, and confirm that the rubber capsdonot�nterferew�thothercomponents.Whenturn�ngthema�nshaftw�ththerubbercapsremoved,therubbercapsaretornoff.Be sure to turn the main shaft after fitting the rubbercapstothen�pples.


1

2

4

3

5

1

4

3

6

7

7

–39–

7. STITCH-TO-ANGLE TABLE BY GAUGE (PITCH AND mm CONVERSION TABLE)

� 2 3 4 5 6 7 8 9

40 4.4 2.9 2.2 �.7 �.5 50 3.4 2.3 �.7 60 2.7 �.8 70 4.5 2.3 �.5 80 3.8 �.9 90 3.2 �.6 �00 2.6

Numberofst�tches

Turn�ngangle

�/8"(3.�7mm)

� 2 3 4 5 6 7 8 9

40 3.6 2.7 2.2 �.8 �.6 50 4.2 2.8 2.� �.7 60 3.4 2.3 �.7 70 2.8 �.9 80 4.7 2.4 �.6 90 4.0 2.0 �00 3.3 �.7

Numberofst�tches

Turn�ngangle

5/32"(3.96mm)

� 2 3 4 5 6 7 8 9

40 3.3 2.6 2.2 �.9 �.6 �.5 50 3.4 2.6 2.0 �.7 �.5 60 2.7 2.� �.6 �.4 70 3.4 2.3 �.7 �.4 80 2.8 �.9 �.4 90 4.8 2.4 �.6 �00 4.0 2.0

Numberofst�tches

Turn�ngangle

� 2 3 4 5 6 7 8 9

40 5.� 3.8 3.� 2.5 2.2 �.9 �.7 50 4.0 3.0 2.4 2.0 �.7 �.5 60 4.8 3.2 2.4 �.9 �.6 70 4.6 2.6 2.0 �.6 80 3.3 2.2 �.7 90 5.6 2.8 �.9 �.4 �00 4.7 2.3 �.6

Numberofst�tches

Turn�ngangle

� 2 3 4 5 6 7 8 9

40 4.4 3.5 2.9 2.5 2.2 2.0 50 4.6 3.4 2.8 2.3 2.0 �.7 �.6 60 3.7 2.8 2.2 �.9 �.6 70 4.6 3.� 2.3 �.9 �.6 80 3.8 2.6 �.9 �.6 90 3.2 2.2 �.6 �00 2.7 �.8

Numberofst�tches

Turn�ngangle

� 2 3 4 5 6 7 8 9

40 4.9 3.9 3.3 2.8 2.5 2.2 50 5.� 3.8 3.� 2.6 2.2 �.9 �.7 60 4.� 3.� 2.5 2.� �.8 �.5 70 5.� 3.4 2.5 2.0 �.7 �.5 80 4.3 2.8 2.� �.7 �.4 90 3.6 2.4 �.8 �.4 �00 3.0 2.0 �.5

Numberofst�tches

Turn�ngangle

� 2 3 4 5 6 7 8 9

40 4.4 3.7 3.2 2.8 2.5 50 4.3 3.4 2.9 2.5 2.2 �.9 60 4.6 3.5 2.8 2.3 2.0 �.8 �.6 70 3.8 2.9 2.3 �.9 �.7 �.5 80 4.8 3.2 2.4 �.9 �.6 90 4.0 2.7 2.0 �.6 �00 3.4 2.3 �.7

Numberofst�tches

Turn�ngangle

� 2 3 4 5 6 7 8 9

40 4.4 3.7 3.3 2.9 50 4.� 3.4 2.9 2.6 2.3 60 4.� 3.3 2.7 2.4 2.� �.8 70 4.5 3.4 2.7 2.3 �.9 �.7 80 3.8 2.8 2.3 �.9 �.6 90 4.8 3.2 2.4 �.9 �.6 �00 4.0 2.7 2.0 �.6

Numberofst�tches

Turn�ngangle

� 2 3 4 5 6 7 8 9

40 5.8 5.0 4.4 3.9 50 5.5 4.5 3.9 3.4 3.0 60 5.5 4.4 3.7 3.� 2.8 2.4 70 4.5 3.6 3.0 2.6 2.3 2.0 80 5.� 3.8 3.� 2.5 2.2 �.9 �.7 90 4.2 3.2 2.5 2.� �.8 �.6 �.4 �00 5.3 3.6 2.7 2.� �.8 �.5 �.3

Numberofst�tches

Turn�ngangle

3/�6"(4.76mm) 7/32"(5.56mm)

�/4"(6.35mm) 9/32"(7.�4mm)

5/�6"(7.93mm) 3/8"(9.52mm)

�/2"(�2.7mm)

–40–

8. GAUGE SETS

Needlegauge Throatplate Feeddog

Cord

BCDEFGHKWLMNPQRSTU

(�nch)�/8

5/323/�67/32�/4

9/325/�63/8

7/�6�/25/83/47/8�

�-�/8�-�/4�-3/8�-�/2

mm3.24.04.85.66.47.�7.99.5��.��2.7�5.9�9.�22.225.428.63�.834.938.�

"S" specificationLowerfeed

"G" specification

--

4002580�4002580240025803400258044002580540025806400258074002580840025809400258�0400258��400258�2400258�3400258�4400258�5400258�6

40033563400257844002578540025786400257874002578840025789400257904002579�400257924002579340025794400257954002579640025797400257984002579940025800

22625�0722625206226253052262540422625503226256022262570�22625800226259092262600622626�052262620422626303226264022262650�226266002262670922626808

22845200-

22845408-

22845606-

22845804-----------

---------

22846�09-

228463072284640622846505

----

Lower feed

23205�07-

23205305-

23205503-

22847800-----------

---------

22848�05-

22848303228484022284850�

----

Throat feed

2.2mm

3.2m

m

ø1.7Lower feed

Needlegauge Presserfoot Needleclamp Sl�d�ngplate

Cord

BCDEFGHKWLMNPQRSTU

(�nch)�/8

5/323/�67/32�/4

9/325/�63/8

7/�6�/25/83/47/8�

�-�/8�-�/4�-3/8�-�/2

mm3.24.04.85.66.47.�7.99.5��.��2.7�5.9�9.�22.225.428.63�.834.938.�

400358964003589722640353226404522264055�2264075922640858226409572264�0542264�2522264�35�2264�4502264�6582264�7572264�8562264�9552264205222642�5�

�039�852-

�0392058-

�0392256-

�0392454--

�039275�-

�03930562284445022844559

----

(Locomobile forked top) Lower feed

--

228�6557228�6656228�6755228�6854228�6953228�70504003394�228�7�594003394540033947400339494003395�40033953400339554003395740033959

40026027400260294002603�400260334002603540026037400260394002604�400260434002604540026047400260494002605�400260534002605540026057400260594002606�

Common�tallspecification

(Locomobile forked top)

2260�058

2260��57

2260�256

2260�355


22600555

22600654

22600753

22600852


Sliding plate, left asm.

Sliding plate, right asm.

2.4m

m

2.0m

m

"S" specificationLowerfeed

"G" specification

(1) LH-4128

4003493�


Sliding plate, front asm.

–4�–

Needlegauge Throatplate Feeddog Presserfoot Needleclamp

Cord

BDEFGH

(�nch)�/8

3/�67/32�/4

9/325/�6

mm3.24.85.66.47.�7.9

22627�522262735022627459226275582262765722627756

Swivel guide

22625�07226253052262540422625503226256022262570�

226280022262820022628309226284082262850722628606

400335634003356440033565400335664003356740033568

For taping

2264705�22647�5022647259226473582264745722647556

400260274002603�40026033400260354002603740026039

Standardø1.4

1.4m

m

0.9m

m2.

0mm

Cord

BDEFGH

(�nch)�/8

3/�67/32�/4

9/325/�6

mm3.24.85.66.47.�7.9

2260�058 22600555



Needlegauge Sl�d�ngplate

(2) LH-4128F

1.7

400358834003588440035885400358864003588740035888

ø1.4

1.15

4003493� 23206709


Sliding plate, front asm.(Tape attaching)

–42–

(3) LH-4128-7

BCDEFGHKWLMNPQRS

(�nch)�/8

5/323/�67/32�/4

9/325/�63/8

7/�6�/25/83/47/8�

�-�/8�-�/4

mm3.24.04.85.66.47.�7.99.5��.��2.7�5.9�9.�22.225.428.63�.8

--

228�6557228�6656228�6755228�6854228�6953228�70504003394�228�7�594003394540033947400339494003395�4003395340033955

4003588�40025485400254904002549�400254924002549340025494400254954002549640025498400254994002550040025502400255034002550440025505


40035890400258�7400258�8400258�9400267�5400258204002582�400258224002582340025824400258254002582640025827400258284002582940025830

40053705-

4002583�4002583240025833400258344002583540025836400258374002583840025839400258404002584�400258424002584340025844

400358964003589722640353226404522264055�2264075922640858226409572264�0542264�2522264�35�2264�4502264�6582264�7572264�8562264�955

40026027400260294002603�400260334002603540026037400260394002604�400260434002604540026047400260494002605�400260534002605540026057


BCDEFGHKWLMNPQRS

(�nch)�/8

5/323/�67/32�/4

9/325/�63/8

7/�6�/25/83/47/8�

�-�/8�-�/4

mm3.24.04.85.66.47.�7.99.5��.��2.7�5.9�9.�22.225.428.63�.8

40025247

40025248

40025249

40025250Common�tallspecification

40025235

40025236

40025239


4003�358


�0209203

�0209500

�0209807

�0209906


Cord

Needlegauge Throatplate Feeddog Presserfoot Needleclamp

"S" specification"G" specification

(Locomobile forked top)(Locomobile forked top)

2.2m

m3.2mmø1.7

2.4m

m

2.0m

m

Cord


Needlegauge Sl�d�ngplate W�per




–43–

(4) LH-4168-7

Needlegauge ThroatplateFeeddog

PresserfootNeedleclamp Needleclamp

(w�thathreadtr�mmer) (left) (r�ght)

BCDEFGHKLMNQ

(�nch)�/85/323/�67/32�/4

9/325/�63/8�/25/83/4�

mm3.24.04.85.66.47.�7.99.5

�2.7�5.9�9.�25.4

400358774002606340026065400260674002606940026070400260724002607440026076400260784002608040026082


40035878400260844002608640026088400260904002609�4002609340026095400260974002609940026�0�40026�03


--

228�6557228�6656228�6755228�6854228�6953228�7050228�7�5940033945400339474003395�

4003588�40025485400254904002549�4002549240025493400254944002549540025498400254994002550040025503


40035890400258�7400258�8400258�9400267�5400258204002582�4002582240025824400258254002582640025828

40053705-

4002583�400258324002583340025834400258354002583640025838400258394002584040025842

400358964003589722640353226404522264055�2264075922640858226409572264�2522264�35�2264�4502264�757

BCDEFGHKLMNQ

(�nch)�/85/323/�67/32�/4

9/325/�63/8�/25/83/4�

mm3.24.04.85.66.47.�7.99.5

�2.7�5.9�9.�25.4

40025247

40025248


40025235

40025236


4003�358


�0209203

�0209500

�0209807�0209906


Cord

Cord







2.4m

m

2.0m

m

2.2m

m3.2mmø1.7

(Locomobile forked top) (Locomobile forked top)

–44–

Needlegauge ThroatplateFeeddog

PresserfootNeedleclamp Needleclamp

(w�thathreadtr�mmer) (left) (r�ght)

(5) LH-4188-7

BCDEFGHKLMNQ

(�nch)�/85/323/�67/32�/4

9/325/�63/8�/25/83/4�

mm3.24.04.85.66.47.�7.99.5

�2.7�5.9�9.�25.4

B�402-526-BA0-AB�402-526-CA0-AB�402-526-DAL-A

�02-28559B�402-526-FAL-AB�402-526-GAL-AB�402-526-HAL-AB�402-526-KAL-AB�402-526-LAL-A

�02-28856�02-28955�02-29�5�


B�402-526-BA0-AB�402-526-CA0-AB�402-526-DAR-A

�02-28567B�402-526-FAR-AB�402-526-GAR-AB�402-526-HAR-AB�402-526-KAR-AB�402-526-LAR-A

�02-28864�02-28963�02-29�69


--

228�6557228�6656228�6755228�6854228�6953228�7050228�7�59

4003588�40025485400254904002549�4002549240025493400254944002549540025498400254994002550040025503


40035890400258�7400258�8400258�9400267�5400258204002582�4002582240025824400258254002582640025828

40053705-

4003589�4005000940035892400500�0400500��4003589340035894

400358964003589722640353226404522264055�2264075922640858226409572264�2522264�35�2264�4502264�757

BCDEFGHKLMNQ

(�nch)�/85/323/�67/32�/4

9/325/�63/8�/25/83/4�

mm3.24.04.85.66.47.�7.99.5

�2.7�5.9�9.�25.4

40025247

40025248


40025235

40025236


�0209203

�0209500

�0209807�0209906


4003�358


Cord


Cord






2.4m

m

2.0m

m

ø1.7

(Locomobile forked top) (Locomobile forked top)

ø2.4

2.2m

m3.2mm

–45–

CORRECTIVE MEASURES

™ Remove sharp edge or burr us�ng a f�nesandpaper. Pol�sh the surface of thebobb�n case rest�ng grooveon the throatplate using a buffing wheel.

™ Adjusttheneedlethreadtens�on.™ Reduce the clearance. (Refer to "6-3.

Adjust�ngthe�nnerhookgu�de".)™ Referto"6-4.Needle-to-hookrelat�on".™ Increase the amount of o�l suppl�ed to

thehookaccord�ng to ("4-3.Adjust�ng theamount of o�l �n the hook (exclud�ng dryhooktype(DSandDF))".

™ Adjusttheneedlethreadtens�on.™ Reduce the tens�on of the spr�ng and

�ncreasethestroke.™ Referto"6-4.Needle-to-hookrelat�on".™ W�ndthethreadontheneedle.

™ Use the thread gu�de equ�pped w�th feltpad.

™ Referto"6-4.Needle-to-hookrelat�on".

™ Referto"6-4.Needle-to-hookrelat�on".™ T�ghtenthepresserspr�ngregulator.

™ Referto"6-4.Needle-to-hookrelat�on".™ Replacetheneedlebyth�ckerones.™ W�ndthethreadontheneedle.

™ Threadthebobb�ncasecorrectly.

™ Remove rough sur face us �ng a f �nesandpaper or pol�sh the surface us�ng abuffing wheel.

™ Replacethebobb�northehook.™ Refer to "6-3.Adjust�ng the �nner hook

gu�de".™ Adjustthebobb�nthreadtens�on.™ Adjust the tens�on componentson the

bobb�nw�nder.

TROUBLES

�. Threadbreakage

(Thread�suntw�stedorscraped.)

(Needlethread2to3cm�sleftonthe wrong s�deofthefabr�c.)

2. St�tchsk�pp�ng

3. Loosest�tch

CAUSES

1 There �s a sharpedge or burr on thethreadpath, needle po�nt, hookbladepo�nt or bobb�n case rest�ng groove onthethroatplate.

2 Needlethreadtens�on�stooh�gh.3 Bobb�n caseopen�ng leverprov�desan

excess�veclearanceatthebobb�ncase.4 Hookbladepo�nth�tstheneedle.5 Hook�snotlubr�catedproperly.

6 Needlethreadtens�on�stoolow.7 Threadtake-upspr�ng�stoot�ghtand�ts

stroke�stoosmall.8 Needle-to-hookt�m�ng�swrong.9 Threaduntw�sts.

!0 Un�form thread loopscannotbe formedwhenmak�ngcha�n-offthread.

1 Clearancebetween theneedle and thehookbladepo�nt�stoogreat.

2 Needle-to-hookrelat�on�swrong.3 Press�ngforceofthepresserfoot�snot

enough.4 Needlebarhe�ght�swrong.5 Needlesareal�ttletooth�n.6 Synthet�cthreadorth�nthread�sused.

1 Bobb�n thread does not pass throughthe forkedendof the tens�onspr�ngonthebobb�ncase.

2 Threadpathhasroughsurface.

3 Bobb�ndoesnotsp�nsmoothly.4 Bobb�ncaseopen�ngleverprov�destoo

muchclearanceatthebobb�n.5 Bobb�nthreadtens�on�stoolow.6 Bobb�n�swoundtoot�ghtly.

9. TROUBLES AND CORRECTIVE MEASURES

Documents

LH-4128,28-7,68-7,88-7 INSTRUCTION MANUAL (ENGLISH) · 3) Press ng the s de of front cover !5 n the d rect on of the arrow, open the front cover toward you. Be sure to open / close