Mitsubishi Electric LU2-4400-B0B User manual

A180E269P02
LOCKSTITCH COMPOUND FEED INDUSTRIAL SEWING MACHINES
INSTRUCTION MANUAL
LU2-4400-B0B (Single-Needle)
LU2-4420-B0B (Double-Needle)
MODEL

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Mitsubishiindustrialsewingmachine.
Pleasereadthisinstructionmanualbeforeoperatingthesewingmachine.Pleasereadalso
“SafetyManual”,“InstructionmanualforMitsubishiLimiservoX”andoperatethesewing
machinecorrectlyandsafely.
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

CONTENTS
USAGE PRECAUTION ……………………………………………… 1
1Lubrication(1)………………………………………………………………………… 1
2Lubrication(2)………………………………………………………………………… 1
3Lubricationcondition………………………………………………………………… 2
4Adjustmentoflubricationtotherotatinghook ………………………………… 2
5Installationofthebeltcover ……………………………………………………… 2
6Precautiononoperation …………………………………………………………… 2
HOW TO USE ……………………………………………… 3
1Installationofneedles ……………………………………………………………… 3
2Windingofthebobbinthread……………………………………………………… 3
3Selectionofthethread……………………………………………………………… 4
4Threadingofneedlethreads ……………………………………………………… 4
5Adjustmentoffeed(stitch)lengthandbackstitch……………………………… 5
6Settingofbobbins …………………………………………………………………… 5
7Threadingofbobbinthreads ……………………………………………………… 6
8Adjustmentofbobbinthreadstension…………………………………………… 6
9Balanceofthreadstension ………………………………………………………… 6
:Adjustmentofneedlethreadstension …………………………………………… 6
AAdjustmentofthepresserfootpressure………………………………………… 6
BTimingbetweentherotatinghookmotionandtheneedlemotion…………… 7
CAdjustmentofthefeeddogheight………………………………………………… 8
D
Relationshipbetweentherotatinghookmotionandthethreadtake-uplevermotion … 9
ERelationshipbetweentherotatinghookmotionandtheopenermotion …… 9
FRelationshipbetweentheneedlemotionandthefeeddogmotion…………… 10
GSafetyclutch ………………………………………………………………………… 11
HAdjustmentofupperfeedlength(needleside) ………………………………… 12
IAdjustmentofforward/backwardfeedlength ………………………………… 12
JAdjustmentoftheoutsidepresserfootandtheinsidepresserfoot ………… 12
SPECIFICATIONS ……………………………………………… 14
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

1 Lubrication (1)
Filltheoilreservoirwithoilupto“H”mark.
Oillevelshouldbeperiodicallychecked.Ifoillevel
isfoundbelow“L”levelreplenishoilto“H”level.
Foroil,use“MC70M”speciedbyMitsubishi.
※Refer
MC70M：Specicgravity(15℃ )=0.86(g/cm3)
：Viscosity(40℃ )=10.9(mm2/s)
2 Lubrication (2)
Whenanewsewingmachineisusedforthe
rst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
arrowsinthebelowgure.
USAGE PRECAUTION
Oillevelmark
—1 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

USAGE PRECAUTION
3 Lubrication condition
Seedrippingofoilthroughtheoilsightwindowto
checkoilingconditionduringoperation.
Conrmthatoilhasbeendrainedfromtheoil
tankwhentheoperationisstopped.
Whendust,etc.accumulateintheoiltank,remove
therubberplugtoclean.
4 Adjustment of lubrication to the
rotating hook
5 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.
6 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.
Oilsight
window
Rubberplug
Adjusting
screw
Decrease Increase
Nut
—2 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

HOW TO USE
1 Installation of needles
Note: Before installing the needles, be sure to turn o󱐯 the power.
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
Double-Needle
Inserttheneedleuptothebottomofneedle
clampandtightenthescrewkeepingthe
longgroovesideofneedlefacetoface
Insufficientinsertion
Gap
Longgroovesareopposite
Longgroove
leftside
Needledistorted
Single-needle
—3 —
From the library of Superior Sewing Machine & Supply LLC - www.supsew.com

HOW TO USE
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 needle threads
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.
LU2-4400
LU2-4400 : Needlepart
LU2-4420
LU2-4420(LU2-4400 : refertotheonlyleftthread)
to , to (Detail)
L12 L14 R10 R12
to (Detail)
L12 L14
Leadthethreadleftward Leadthethreadrightward
(Seedetailedfigure)
R2
L2
R1L1
R 10
R 11
L 10
R5R6
R3
R4
R7
R9
R8
L3
L8 L7
L4
L 11
L 12
L 13
L 14
L 15
L 15
L 16
L 16
R 12
R 13
R 14
L5
L9
L6
Leadthethread
rightward
Stwistthread
Ztwistthread
A B A AB
—4 —
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HOW TO USE
5 Adjustment of feed (stitch)
length and backstitch
●Adjustmentoffeed(stitch)length…Adjustfeed
lengthbyturningthefeedlengthsettingdial
whiledepressingthereversesewinglever.
●Backstitch…Directionofstitchingcanbe
reversedbydepressingthereversesewing
lever.
6 Setting of bobbins
( 1 ) Pullout5cmthreadtailfrombobbins.
( 2 ) Putbobbinsintohooksinthedirectionasthe
followinggure.
Feedlengthsettingdial
Reversesewinglever
Bedslide
Hook
Bedslide
Thread
Hook
—5 —
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7 Threading of bobbin threads
( 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.
8
Adjustment of bobbin threads tension
9 Balance of threads tension
:
Adjustment of needle threads tension
●Needlethreadstensionshouldbeadjustedon
thebasisofbobbinthreadstension.
●Adjustneedlethreadstensionbyturning
threadtensionnuts.
 Needlethreadstensioncanbealsoadjustedby
changingintensityandmovablerangeofthe
threadtake-upspringincaseofsewingthe
specialfabricandthread.
A
Adjustment of the presser foot pressure
Adjustthepresserfootpressureaccordingtothe
fabricbyturningthepressureadjustingscrew.
HOW TO USE
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
Threadtensionnut
Tighten
Loosen
Thread
①
②
Thread
Opener
Loosen Tighten
Threadtensionscrew
Pressureadjusting
screw
Strengthen Weaken
—6 —
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B Timing between the rotating
hook motion and the needle
motion
Incaseofdouble-needle,adjustrightandleft
timinginthesamewayatthesametime.
Note:Ifyouremovethepresserfoot,thethroat
plate,andthefeeddog,itmakeseasierto
adjust.
( 1 ) Setfeedlengthto6mm.
( 2 ) LoosenallscrewsⒶ,Ⓑ,Ⓒ.
Note:Becarefulnottodisengagethelarge
gearandthesmallgear.
( 3 ) Lifttheneedlebar2.4mm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0.05mmorlower.
( 5 ) TightenscrewsⒶ,Ⓑ.
 Note:BecarefulnottoovertightenscrewsⒷ.
( 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3mm.
( 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comelightlyincontactwiththe
needle.
HOW TO USE
Tipof
thehook
0.05mmorlower
0.05mm
(a)Positionoftheneedlebar:
Thelowestposition
(b)Positionoftheneedlebar:
2.4mmliftedpositionfrom(a)
ScrewⒶ
ScrewⒷ
SetScrewⒸ
—7 —
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