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
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