JUKI LU2-4652-B1T User manual

A181E101P01
SINGLE-NEEDLE LOCKSTITCH COMPOUND-FEED
AUTOMATIC UNDERTRIMMER
INDUSTRIAL SEWING MACHINE
MODEL
INSTRUCTION MANUAL
LU2-4652-B1T

PRECAUTION BEFORE STARTING OPERATION
1 Safety Precautions
1 . Whenturningthepoweron,keepyourhandsandngersawayfromtheareaaround/
undertheneedleandtheareaaroundthepulley.
2 . Thepowermustbeturnedo󱐯whenthemachineisnotused,orwhentheoperator
leaveshis/herseat.
3 . Thepowermustbeturnedo󱐯beforetiltingthemachinehead,installingorremoving
the“V”belt,adjustingthemachine,orreplacingparts.
4 . Avoidplacingngers,hairs,obstacles,etc.nearthepulley,“V”belt,bobbinwinder
wheel,ormotorwhenthemachineisinoperation.Injurycouldresult.
5 . Don’tputngersintothethreadtake-uplevercover,around/undertheneedle,or
pulleywhenthemachineisinoperation.
6 . Ifthebeltcover,thengerguard,and/ortheeyeguardareinstalled,don’toperate
themachinewithoutthesesafetydevices.
2 Precaution before Starting Operation
1 . Ifthemachine’soilpanhasanoilsump,neveroperatethemachinewithoutllingoil
init.
2 . Ifthemachineislubricatedbyadropoiler,neveroperatethemachinewithout
lubricating.
3 . Whenanewsewingmachineisoperated,verifytherotationaldirectionofthepulley
withthepoweron.
 (Thepulleyshouldrotatecounterclockwisewhenviewedfromthepulley.)
4 . Verifyvoltageand(singleorthree)phaseindicatedonthenameplateofthemotor.
3 Precaution for Operating Conditions
1 . Avoidusingthemachineatabnormallyhightemperature(35℃orhigher)orlow
temperature(5℃orlower).Otherwise,machinefailuremayresult.
2 . Avoidusingthemachineindustyconditions.
3 . Avoidusingthemachineinconditionslledwithalotofelectricnoisessuchashigh-
frequencywelders.
INTRODUCTION

Thank you very much for purchasing industrial sewing machine.
Please read this instruction manual before operating the sewing machine. Please read also
“Safety Manual”, “Instruction manual for LIMISERVO” and operate the sewing machine
correctly and safely.

CONTENTS
PREPARATION FOR OPERATION ……………………………………………… 1
1Installingtheaircylinderassembly ……………………………………………… 1
2Connectingtheelectriccablestothecontrolbox ……………………………… 1
3Adjustmentofthestitchlengthbeforetrimming ……………………………… 3
4Operationspeedadjustmentofinstantalternatingaircylinder ……………… 4
5Heightadjustmentoftheautomaticpresserfootlifter………………………… 4
6Adjustmentoftheneedlestoppingposition……………………………………… 5
USAGE PRECAUTION ……………………………………………… 6
1Lubrication( 1 )  ……………………………………………………………………… 6
2Lubrication( 2 )  ……………………………………………………………………… 6
3Lubricationcondition………………………………………………………………… 7
4Adjustmentoflubricationtotherotatinghook ………………………………… 7
5Precautionforthebuilt-intypedetector ………………………………………… 7
6Installationofthebeltcover ……………………………………………………… 7
7Precautiononoperation …………………………………………………………… 7
HOW TO USE ……………………………………………… 8
1Installationoftheneedle …………………………………………………………… 8
2Windingofthebobbinthread……………………………………………………… 8
3Selectionofthethread……………………………………………………………… 9
4Threadingoftheneedlethread…………………………………………………… 9
5Adjustmentoffeed(stitch)lengthandbackstitch……………………………… 10
6Settingofthebobbin………………………………………………………………… 10
7Adjustmentoftheneedlethreadguide ………………………………………… 10
8Threadingofthebobbinthread…………………………………………………… 11
9Adjustmentofthebobbinthreadtension………………………………………… 11
:Balanceofthreadstension ………………………………………………………… 11
AAdjustmentoftheneedlethreadtension………………………………………… 11
BAdjustmentofthepresserfootpressure………………………………………… 11
CAdjustmentoftheoutsidepresserfootandinsidepresserfoot ……………… 12
DInstantalternatingswitch ………………………………………………………… 13
EThestopperscrewforadjustingthemaximumalternatingstroke ………… 13
FInstallingthefeedregulatorbracket……………………………………………… 14
GAdjustmentofthealternatingstrokesensingpotentiometer ………………… 14
HTimingbetweentherotatinghookmotionandtheneedlemotion…………… 15
IAdjustmentofthefeeddogheight………………………………………………… 16
J
Relationshipbetweentherotatinghookmotionandthethreadtake-uplevermotion … 17
KRelationshipbetweentherotatinghookmotionandtheopenermotion …… 17
LRelationshipbetweentheneedlemotionandthefeeddogmotion…………… 18
MSafetyclutch ………………………………………………………………………… 19
NAdjustmentofupperfeedlength(needleside) ………………………………… 20
OAdjustmentofforward/backwardfeedlength ………………………………… 20
PInstallationofthemovableknife…………………………………………………… 21
QInstallationpositionofthethreadtrimmercam………………………………… 22
RAdjustmentofthethreadtrimmercam ………………………………………… 22
SAdjustmentofthethreadtensionreleasing……………………………………… 23
T
Adjustmentofmeshingpressurebetweenthemovableknifeandthexedknife … 24
USharpeningofthexedknife ……………………………………………………… 24
SPECIFICATIONS ……………………………………………… 25

1 Installing the air cylinder assembly
( 1 ) Aligntheaircylinderassemblytothebackofthearmasshownbelowandthentthedrivinglink
intothepin.
 Fitadrivinglinkbetweenthenylonwashers.
( 2 ) Installtheaircylinderassemblyonthebackofthearm.
 Tightenthebracketandthebackofthearmwiththeenclosedbolt.
2 Connecting the electric cables to the control box
Connectwiresandpipesasfollows.
( 1 ) Installthesolenoidvalveandthelterregulatorassembly①withinthereachoftheurethanetube
/cordunderthetable.
( 2 ) Installtwoattachedelbowunions②,③ontherearcoverlocatingatthebackofthearm.
( 3 ) Arrangepipingbyurethanetubesbetweentheupperelbowunion②installedbystep( 2 ) andthe
portB( ④ B )oftheupperpresserfootliftersolenoidvalve④,andbetweenthelowerelbowunion
③andtheportA( ④ A ).
( 4 ) Connecttheconnecter⑤ofthepresserbarliftersolenoidvalve④tothepresserfootlifter
connectoronthecontrolbox.
( 5 ) Connecttheurethanetube⑥fromthetopofthesewingmachinetotheportA( 7 Ⓐ ) ofthe
instantalternatingsolenoidvalve⑦.
( 6 ) Connectthe3-pinconnector⑧ofthesewingmachineconnectorandtheconnectoroftheinstant
alternatingsolenoidvalve⑦.
( 7 ) Whenthekneeswitch⑨issubstitutedfortheinstantalternatingswitch,connectthe2-pin
connector⑩suppliedasanoptionBtothekneeswitch.
Drivinglink
Nylon
washer
Bracket
Backofthearm
Bolt
Aircylinderassembly
Pin
PREPARATION FOR OPERATION
—1 —

( 8 ) Connectbyurethanetubebetweentheupperpartelbowunions⑪installedontheaircylinder
assemblyandportAofthesolenoidvalveassembly⑬.
 Similarly,connecttheurethanetubebetweenlowersideofelbowunions⑫andportBofthe
solenoidvalveassembly.
( 9 ) ConnecttheairsupplysourcetotheINportofthelterregulator①.
(10)Tietogetherurethanetubesandcordswithattachedbindingbands.
Note:Setthestandardairpressureoftheregulatorto0.4MPa(4kgf/cm2).
⑥④Bport ⑬Bport
⑬Aport
④Aport
⑦Aport
INporttotheair
supplysource
Kneeswitch
LF-FM-CFT
(Option)
①
Urethanetube
OPTIONBOPTIONAF・L S.M
⑪
⑫
②
③
⑤
⑨
⑩
⑧
Aircylinderassembly
PREPARATION FOR OPERATION
—2 —

3 Adjustment of the stitch length before trimming
Dependingonsewingconditions,thestitchimmediatelybeforetrimmingmaynotbeformedcorrectly.
Thismaycausethetrimmedtaillengthtobelong.
Inthiscase,adjustthelengthofthestitchimmediatelybeforethetrimmingpositiontoensurethata
properstitchisformed.Asreference,thestandardstitchlengthis1to2mm.Thelengthofthestitch
immediatelybeforetrimmingcanbeadjustedbymovingthepositionoftheknuckletotheair
cylindershaftup/down.Adjustwiththefollowingmethods.
( 1 ) Loosenthenutontheknuckle.
( 2 ) Rotatetheaircylindershaft.
 Adjustthepositionoftheknuckletotheair
cylindershaft.
( 3 ) Thestitchimmediatelybeforetrimmingisas
follows.
・Duringforwardstitching:
Lookingfromabove,turntheshaft
clockwisetochangetoreversestitching.
・Tooshortduringreversestitching:
Lookingfromabove,turntheshaft
clockwise.
・Toolongduringreversestitching:
Lookingfromabove,turntheshaft
counterclockwise.
Thestitchlengthchangesabout1mmwhen
theshaftisrotatedonce.
Inthepositionoftheknucklewhenshipping,
dimensionAbetweenthelowersurfaceofthe
aircylinderandtheuppersurfaceofthe
knuckleis22mmliketherightgurewiththe
aircylinderdrawnin.
A
Shaft
Nut
Knuckle
PREPARATION FOR OPERATION
—3 —

4 Operation speed adjustment of instant alternating air cylinder
( 1 ) Toadjustthespeedoftheaircylinderatthemaximuminstantalternating,adjustthehandle①
withplatedlocknutonthedualspeedcontrolleroftheinstantalternatingsolenoidvalve(lower
side).
( 2 ) Toadjustthespeedoftheaircylinderattheinstantalternatingreturn,adjustthehandle②with
theblackcoloredlocknutonthedualspeedcontrolleroftheinstantalternatingsolenoidvalve(lower
side).
5 Height adjustment of the automatic
presser foot lifter
Thepresserfootlifterheightattheautomaticpresser
canbeadjusted.
( 1 ) Removethetopcover.
( 2 ) Slidethestopperplateonthepresserfootlifterair
cylinderupanddowntoadjust.
①
②
Stopper
Backofthearm
PREPARATION FOR OPERATION
—4 —

PREPARATION FOR OPERATION
6 Adjustment of the needle stopping position
1 . Adjustment of “UP” position
Whenthepedaliskickeddownbyheel,themachinestopsat“UP”position.
Ifmarksdeviatelargerthan3mm,adjustasfollows.
( 1 )Disconnecttheplug(12pins)ofcablefromthemachinehead.
( 2 )Runthemachineandstopat“UP”position.
( 3 )Whileholdingthepulley,insertthe“Adjustingtool”inthehole Ⓐ,thenturnthetool.
2 . Adjustment of “Down” position
Whenthepedalis“Neutral”themachinestopsat“Down”position.
Ifmarksdeviatelargethan5mm,adjustasfollows.
( 1 )Disconnecttheplug(12pins)ofcablefromthemachinehead.
( 2 )Runthemachineandstopat“Down”position.
( 3 )Whileholdingthepulley,insertthe“Adjustingtool”inthehole Ⓑ,thenturnthetool.
3 . Conrmthestopoperation,thensettheplug(12pins)comingfromthemachineheadintothe
receptacle.
Timingmark
Whitemark
Blackmark
Upposition
Downposition
Adjustingtool
UP
later
earlier
DOWN Timingoftheneedle
Ⓐ
Ⓑ
—5 —

MC70M ：Specific gravity (15℃) = 0.86 (g/cm3)
2
arrows in the below figure.
For oil, use“ MC70M” specified by our company.
Oil level should be periodically checked. If oil level
Fill the oil reservoir with oil up to“ H” mark.
is found below“ L” level replenish oil to“ H” level.
1

   
  
 
USAGE PRECAUTION
Oillevelmark
Lubrication (2)
Lubrication (1)
1
※Refer
：Viscosity (40℃) = 10.9 (mm2/s)
When a new sewing machine is used for the
first time, or sewing machine left out of use for
considerably long time is used again, replenish a
suitable amount of oil to the portions indicated by
—6 —

5 Precaution for the built-in type detector
1 . Sincetheopticaltypedetectingelementisusedinthedetector,preventdustoroilfromstickingto
thedetectingplatewhenthesewingmachinepulleyisremovedforadjustment.
 Iftheyhavestuck,wipethemo󱐯withsoftclothcarefullysothatthesurfaceisnotscratched,do
notletoilpermeatetheclearanceonthedetectingplate.
2 . Incaseofdisconnectionofthepositiondetectorconnector,runningo󱐯thebeltorcomplete
constraintandoverload,themotorisautomaticallyturnedo󱐯afterpredeterminedtimetoprevent
burningofthemotor.(However,incaseofhalf-constraintandoverload,thepowermaynotbe
turnedo󱐯.)Afterthefailureiseliminated,thenormaloperationisresumedbyturningo󱐯thepower
oncethenturningonagain.
 Thesameoperationoccursforthedetectormalfunctionorthelinebreakage.
6 Installation of the belt cover
1 . Installthebeltcoveronthemachinesideforsafety.Refertotheprovidedinstructiondocument
containedinthesamepackage.
2 . Installthebeltcoveronthemotorsideforsafety.
7 Precaution on operation
( 1 ) Whenthepoweristurnedonoro󱐯,keepfootawayfromthepedal.
( 2 ) Itshouldbenotedthatthebrakemaynotworkwhenthepowerisinterruptedorpowerfailure
occursduringsewingmachineoperation.
( 3 ) Sincedustinthecontrolboxmightcausemalfunctionorcontroltroubles,besuretokeepthe
controlboxcovercloseduringoperation.
( 4 ) Donotapplyamultimetertothecontrolcircuitforchecking,otherwisevoltageofmultimeter
mightdamagesemiconductorcomponentsinthecircuit.
3 Lubrication condition
Seedrippingofoilthroughtheoilsightwindowto
checkoilingconditionduringoperation.
4 Adjustment of lubrication to the
rotating hook
USAGE PRECAUTION
Oilsightwindow
Adjustingscrew
IncreaseDecrease
Nut
—7 —

1 Installation of the needle
Note: Before installing the needles, be sure to turn o󱐯 the power.
HOW TO USE
Longgroove
leftside
2 Winding of the bobbin thread
Note: When bobbin thread is wound, keep the presser foot lifted.
Adjustment ●Tension of wound thread Slackwindingisrecommendedforpolyesterthreadand
nylonthread.
●Conically wound thread Movethethreadguidetowardsmallerdiameterofwound
threadlayer.
●Amount of wound thread Loosenthewindingamountadjustmentscrewtodecrease
threadwindingamountandtightenthescrewtoincrease
threadwindingamount.
Windingtension
adjustmentnut
Evenwinding
amountof80%
offullcapacity
Windingamount
adjustmentscrew
Threadguide
—8 —

HOW TO USE
①
Threadtension
releasingbutton
③
②
④
⑤
⑥
⑦
⑧
⑩
⑪
⑫
⑬
⑭
⑨
3 Selection of the thread
Itisrecommendedtouse“S”twistthreadintheleftneedle(viewed
fromfront),and“Z”twistthreadintherightneedle.
Whendiscriminateuseofneedlethreadsisimpossible,use“Z”twist
threadinboththeneedles.
Forbobbinthread,“S”twistthreadaswellas“Z”twistthreadcanbe
used.
4 Threading of the needle thread
1 . Passeachneedlethreadthroughthreadguide(A).
 Note:Whenthinslipperythread(polyesterthreadorlament
thread,etc.)isused,
 Passthethreadthroughthreadguide(B)aswell.
2 . Withthethreadtake-upleverlocatedattheuppermostposition,
passeachneedlethreadintheordershowninthefollowinggure.
 Note:Pushingtheneedlethreadtensionreleasingbuttonshown
inthegurebelowopensthesauceroftheneedlethreadtension
adjuster,andtheneedlethreadcaneasilypulledout.
Stwistthread
Ztwistthread
A B A AB
—9 —

5 Adjustment of feed (stitch)
length and backstitch
●Adjustmentoffeed(stitch)length…Adjustfeed
lengthbyturningthefeedlengthsettingdial
whilepushingPUSHlever.
Note:Dependinguponthestitchlength,the
maximumsewingspeedsaredi󱐯erent.
 Withreferringtothespecicationson
page25,pleaseoperatethesewing
machineatthespeedlessthanthe
matchingsewingspeedwiththestitch
length.
●Backstitch…Directionofstitchingcanbe
reversedbydepressingthereversesewing
leverorpushingthetouchbackswitch.
6 Setting of the bobbin
( 1 ) Pullout5cmthreadtailfromthebobbin.
( 2 ) Putthebobbinintothehookinthedirection
asthefollowinggure.
7 Adjustment of the needle
thread guide
Adjusttheneedlethreadguideoftheneedle
threadtensionadjusteraccordingtothefabric,the
thread,andsewingcondition.
Needle
thread
guide
position
Leftside Center Rightside
Fabric Heavy Standard Light
Needle
thread
supply
More Standard Less
HOW TO USE
Touchbackswitch
Feedlengthsettingdial
Reversesewinglever
Bedslide
Hook
Bedslide
Thread
—10 —

8 Threading of the bobbin thread
( 1 ) Putbobbinthreadintotheslit①,passunder
thelug②andextenditabovethebed.
( 2 ) Whileholdingtwoneedlethreadswithyour
lefthand,turnthepulleyonerotationwith
yourrighthand.Thebobbinthreadswill
comeupwhenneedlethreadsareliftedup
asshowninthegure.Needlethreadsand
bobbinthreadsshouldbealignedandled
backwardtogether.
9
Adjustment of the bobbin thread tension
: Balance of threads tension
A
Adjustment of the needle thread tension
Toadjustneedlethreadtension,turnthethread
tensionnut.
Pre-tensionnut
Tighten
Loosen
Tighten
Loosen
Threadtensionnut
B
Adjustment of the presser foot pressure
Adjustthepresserfootpressureaccordingtothe
fabricbyturningthepressureadjustingscrew.
Weaken Strengthen
HOW TO USE
Thread
①
② Opener
Loosen Tighten
Threadtensionscrew
A○
B×
C×
Balancedtension
Tighttheneedlethreadtensionor
loosethebobbinthreadtension
Loosetheneedlethreadtensionor
tightthebobbinthreadtension
—11 —

C
Adjustment of the outside presser
foot and inside presser foot
1 . Adjustment of alternating movement
( 1 ) Thealternatingmovementontheoutside
presserfootandinsidepresserfootcanbe
adjustedbyusingtheadjustingdiallocated
onthetopcover.
( 2 ) Facethedesirednumberprintedonthedial
tothematchingmarklocatedonthetop
cover.
( 3 ) Thenumberprintedonthedialrepresents
thepossibleprotrusionoftheoutsidepresser
footandinsidepresserfootfromthethroat
platewhenthealternatingmovementson
theseareevenlyset.
( 4 ) Ifthealternatingmovementsareevenlyset,
theycanbereadjustedupto2.0to6.0mm.
2 .
To change the balance of the alternating movements
between the outside presser foot and inside presser foot
( 1 ) Forexample,toincreasetheriseoftheinside
presserfoot,anddecreasetheriseofthe
outsidepresserfoot.
①Removetherubberpluglocatedonthetop
cover.
②Turnthepulleyuntiltheoutsidepresserfoot
isslightlyraisedfromthethroatplate.
③LoosenthesetscrewⒶlocatedonthefeed
liftingrockshaftcrank(right).
④Thebuilt-inspringpullsdowntheoutside
presserfootuntilitmakescontactwiththe
throatplate.Then,tightenthesetscrewⒶ.
⑤Thiscompletestheadjustment,i.e.,the
protrusionoftheoutsidepresserfoothas
beendecreasedbyasetdistance.And,the
verticalmotionoftheinsidepresserfoothas
beenincreasedbythatsamedistance.
( 2 ) Asacontrarycase( 1 ) ,todecreasetherise
oftheinsidepresserfoot,andincreasethe
riseoftheoutsidepresserfoot.
 First,turnthepulleyuntiltheinsidepresser
footisslightlyraisedfromthethroatplate.
Next,loosenthescrewⒶ.Finally,tightenthe
screwⒶagain.
 Thisdecreasestheriseoftheinsidepresser
foot.
Rubber
plug
Matchingmark
Alternatingstrokeadjustingdial
Inside
presserfoot
Outside
presser
foot
2.0to6.0mm
Feedliftingrock
shaftcrank(right)
Rubberplug
Ⓐ
SecondscrewⒶ
Firstscrew
Uppereccentricfeedliftingcam
HOW TO USE
3 . How to install the upper eccentric feed lifting cam
( 1 ) Turnthepulleyandstopitattheposition
wherethethreadtake-uplevercomestothe
lowest.
( 2 ) Inthiscondition,removetherubberplug
locatedonthearm.Locatethesecondscrew
Ⓐintheuppereccentricfeedliftingcamas
showninthegure.Andtightenit.
—12 —

D Instant alternating switch
Duringthesewingoperation,ifasewingmaterial
hasastep,hittheinstantalternatingswitch,then
thealternatingupanddownmovementinstantly
becomesmuchbiggertogetoverthestep.
Hitonce,ON Thealternatingup
anddownmovement
becomeshighest(It
isadjusted6mmis
thehighestwhen
thesewingmachine
isshippedfromthe
factory).
(LightingLEDlamp)
Hittwice,OFF Thealternatingup
anddownmovement
becomesthenormal
strokecontrolledwith
thealternatingstroke
adjustingdial.
Note1:Thekneeswitchalsocanbeusedasthe
instantalternatingswitch.
 2:Italsocanbesetthealternatingupand
downmovementtothehighestonly
whilepressingtheinstantalternating
switch.
E The stopper screw for adjusting
the maximum alternating stroke
Themaximumalternatingstrokecanbeadjusted
withthestopperscrewshownintherightgure.
◎Themaximumalternatingstrokeisxedat6
mmwhenthesewingmachineisshippedfrom
thefactory.
Ifthemaximumalternatingstrokeisrequired
tomakesmaller,takethefollowingprocedures.
Note:Donotsetthealternatingstroketomore
than6.5mm,becauseitmaycausefailure.
1. Setthealternatingstrokeadjustingdialtothe
desirednumberofthestroke.
2. Loosenthenutshownintherightgure.
3. Tightenthestopperscrewuntilithitswiththe
specialscrew.
4. Tightenthenut.
Stopperscrew
Nut
Instantalternatingswitch
Alternatingstrokeadjustingdial
Stopperscrew
Specialscrew
Nut
Redmark
(positionat6mm)
HOW TO USE
—13 —

F
Installing the feed regulator bracket
Ifitisnecessarytodismountandreassemblethe
feedregulatorbracketanditsrelatedparts,install
itasfollows.
Note:Ifthefeedregulatorbracketispoorly
positioned,theresultantalternating
movementsmaybetooshortorlongcausing
defectivemachineoperation.
( 1 ) SetthegapbetweenspecialscrewⒶlocated
ontheregulatorshaftandthesidewallof
themachinearmto42.6mmasillustratedto
theleft.(Usea42.6mmspacerbetweenthese
parts.Thisfacilitatestheoperation.)
( 2 ) Withthefeedregulatorstudheldasexplained
instep( 1 ) above,adjustthefeedregulator
bracket.Thisadjustmentshouldinsureagap
of2.3mmbetweentheperipheryofpinⒷ
locatedonthefeedregulatorbracketandthe
topcoverinstallingfacelocatedonthearm.
TightenscrewⒸ.
G Adjustment of the alternating
stroke sensing potentiometer
(Pleaserefertotheinstructionmanualfor
LIMISERVOXGMFYalso.)
Note:Incaseofmaladjustment,thepropersewing
speedmaynotbeobtained.
( 1 ) Turno󱐯thepowerswitch.
( 2 ) RemoveallconnectorsexceptOPTIONB
connector.
( 3 ) Removethetopcoverintheconditionwhich
setthealternatingstrokeadjustingdialfor
scale2.
( 4 ) Turnonthepowerswitch,andthensetthe
operationpanelofthecontrolboxtotheinput
display“V2”attheprogrammingmodeE.
( 5 ) LoosentheslottedboltⒹofthepotentiometer
crank.
 Atthistime,becarefulnottogiveany
bendingtorquetothepotentiometershaft.
( 6 ) Fixthedistancebetweenthefeedregulator
shaftspecialscrewⒶandtheinnerwallof
thesewingmachinearm42.6mm.
 (Itisrecommendedtousethespacersized
42.6mmforquickxing.)
( 7 ) Turnthepotentiometershaftsothatthe
inputdisplay“V2”indicates280to289.
Feedliftingrock
shaftcrank(right)
Feedregulatorshaft
Feedregulatorbracket
42.6mm
2.3mm
Ⓑ
Ⓐ
Ⓒ
Potentiometer
42.6mm
Ⓓ
Ⓐ
HOW TO USE
( 8 ) TightentheslottedheadboltⒹofthe
potentiometercrank.
( 9 ) Makesureagainthattheinputdisplay“V2”
indicates280to289.Ifthedisplayindicates
thedi󱐯erentnumberfrom280to289,adjust
thepotentiometershaftagain.
(10) Turno󱐯thepowerswitch.
(11) Putthetopcoverbackintheconditionwhich
setthealternatingstrokeadjustingdialfor
scale2.
(12) Connectalltheconnectorsasbefore.
—14 —

H Timing between the rotating
hook motion and the needle
motion
Note:Ifyouremovethepresserfoot,thethroat
plate,andthefeeddog,itmakeseasierto
adjust.
( 1 ) Setfeedlengthto6mm.
( 2 ) LoosenallscrewsⒶ, Ⓑ, Ⓒ.
 Note:Becarefulnottodisengagethelarge
gearandthesmallgear.
( 3 ) Lifttheneedlebar2.4mmfromthelowest
position.Refertotimingmarksshowninthe
gure.
( 4 ) Slidethehooksaddlerightandleftsothat
thegapbetweenthetipofthehookandthe
scarfoftheneedleis0.05mmorlower.
( 5 ) TightenscrewsⒶ, Ⓑ.
 Note:BecarefulnottoovertightenscrewⒷ.
( 6 ) Slidethelargegearrightandleftsothatthe
tipofthehookpositionisinthecenterofthe
needleandtightenscrewsⒸ.
 Note:Checkthelargegearandthehook
saddleisn’tincontactanditsdistanceis
lessthan3mm.
( 7 ) Movethetipofthehooktotheneedleside
byturningthepulley.
( 8 ) Returnthemachineheadtotheoriginal
positionandadjusttheneedleguideposition
sothatitcomeslightlyincontactwiththe
needle.
HOW TO USE
Tipof
thehook
0.05mmorlower
0.05mm
（a）Positionoftheneedlebar:
Thelowestposition
（b）Positionoftheneedlebar:
2.4mmliftedpositionfrom(a)
ScrewⒶ
ScrewⒷ
ScrewⒸ
—15 —

I
Adjustment of the feed dog height
Thefeeddogheightandthepresserfootpressure
mustbeadjustedaccordingtothefabric.
◆ Thefabricwillbedamagedifthefeed
dogextendstoohigh,orifthepresserfoot
pressureistoolarge.
◆ Anevenstitchlengthcannotbeassuredif
thefeeddogistoolow,orifthepresserfoot
pressureistoosmall.
◆ Thefeeddogheightisthepositionwherethe
needleisatthetopposition.
Adjustment of the feed dog height
( 1 ) Leanthemachineheadbackward.
( 2 ) Turnthepulleybyhandandstopitatthe
positionwherethefeeddogrisestothe
maximumheight.
( 3 ) Loosenthefeedbarscrew.
( 4 ) Verticallymovethefeedbar(inthedirection
indicatedbythearrowinthegure)toadjust
ittoanadequateheight.
( 5 ) Afteradjusting,tightenthefeedbarscrew.
The feed dog height is factory-adjusted to 1.0 mm.
HOW TO USE
Throatplate
Feeddog
1.0mm
Feedbar
screw
Feedbar
—16 —

J
Relationship between the rotating
hook motion and the thread take-up
lever motion
Whenthetimingbeltisremovedforreplacement,
etc.,therelationbetweentherotatinghookmotion
andthethreadtake-uplevermotionshouldbe
adjustedasfollows:
( 1 ) Turnthepulleyandstopwhenthethread
take-upleverisliftedtothehighestposition.
( 2 ) Leanthemachineheadbackwardandcheck
thatthearrow(timingmark)putonthe
timingbeltisalignedwiththeblacklineon
thebossoflowershaftbearing.
( 3 ) Ifthetimingmarkisnotinlinewiththe
blackline,removethetimingbeltandinstall
itagaintoadjust.
K
Relationship between the rotating
hook motion and the opener motion
( 1 ) Turnthepulleybyyourhandandstopit
atthepositionwheretheopenerholderis
locatedmostremotelyfromthethroatplate.
( 2 ) CheckthatthegapbetweenthelugⒶand
theopenerisapproximately0.2mm.
( 3 ) Ifthegapistoolargeorsmall,loosenthe
openerholderscrewⒷandadjustpositionof
theopener.
HOW TO USE
Timingbeltpulley
Timingmark(arrow)
Blacklineonbossoflowershaftbearing
Timingbelt
Approx.0.2mm
Opener Openerholder
ⒶScrewⒷ
—17 —