Mitsubishi Electric LU2-4710-B1T User manual

A180E363P05
INSTRUCTION MANUAL
LOCKSTITCH COMPOUND-FEED AUTOMATIC UNDERTRIMMER
INDUSTRIAL SEWING MACHINES
LU2-4710-B1T (Single-Needle)
LU2-4730-B1T (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.

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

1 Connecting the electric cables to the control box
Connectwiresandpipesasfollows.
( 1 ) Connectthecables①extendedfromthesewingmachineheadtothecontrolbox,andthenconnect
3-pinconnector②tothesolenoidvalve③usedforactivatingtheaircylindertoalternating
movementinstantly.
Note:Setthestandardairpressureoftheregulator(option)to5kgf/cm2.
(2)Incaseofusingthekneeswitch④asthealternatingswitch,connect2-pinconnector⑤ofOPTION
Btothekneeswitch④.
(3)Connecttheurethanetube⑥extendedfromthesewingmachineheadtoAport⑦ofthesolenoid
valve③.
Note:Foryoursafety,alwaysturno󱐯thepowerswitchwheneverconnectordisconnectconnectors.
PREPARATION FOR OPERATION
⑥
④
⑦
Pportto
theairsupplysource
Aircylinderusedforalternatingmovementis
builtinthesewingmachinehead
Aportto
theflowcontrol
Rport
theexhaustvalve
Solenoidvalve
(Option)
Regulator
(Option)
Kneeswitch
LF-FM-CFT
(Option)
①
OPTIONBOPTIONAF・L S.M.
②
③
⑤
—1 —

2 Setting up the activating speed of the air cylinder
( 1 ) Whencontrolthepullingspeedoftheaircylinder,adjusttheairowofAportonthesolenoid
valve.
( 2 ) Whencontrolthepushingspeedoftheaircylinder,adjusttheexhaustvalveofRportonthe
solenoidvalve.
3 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.
PREPARATION FOR OPERATION
Timingmark
Whitemark
Blackmark
Upposition
Downposition
Adjustingtool
UP上
later
earlier
DOWN下 Timingoftheneedle
Ⓐ
Ⓑ
—2 —

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.
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)
USAGE PRECAUTION
Oillevelmark
—3 —

3 Lubrication condition
Seedrippingofoilthroughtheoilsightwindowto
checkoilingconditionduringoperation.
USAGE PRECAUTION
4 Adjustment of lubrication to the
rotating hook
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.
Adjusting
screw
Decrease Increase
Nut
Oilsightwindow
—4 —

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.
HOW TO USE
HOW TO USE
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
—5 —

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.
 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.
HOW TO USE
Threadtensionreleasingbutton
R1
L1
R2
L2
R3
R4
R5
R6
R7
R8
L3
L4
L5
L6
L7
R9L8
L9 R
10
L 10
R 11 L 10
R 12 L 11
R 13
R 16
L 12
R 14 L 13
L 15
①
Threadtensionreleasingbutton
③
②
④
⑤
⑥
⑦
⑧
⑩
⑪
⑫
⑬
⑭
⑮
⑨
LU2-4730 LU2-4710
Stwistthread
Ztwistthread
A B A AB
—6 —

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24,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 bobbins
( 1 ) Pullout5cmthreadtailfrombobbins.
( 2 ) Putbobbinsintohooks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
HOW TO USE
Feedlengthsettingdial
Reversesewinglever
Touchbackswitch
Bedslide
Hook
Bedslide
Thread
Hook
—7 —

8 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.
9
Adjustment of bobbin threads tension
: Balance of threads tension
A
Adjustment of needle threads tension
Adjustneedlethreadstensionbyturningthread
tensionnuts.
B
Adjustment of the presser foot pressure
Adjustthepresserfootpressureaccordingtothe
fabricbyturningthepressureadjustingscrew.
HOW TO USE
Pre-tensionnut
Tighten
Loosen
Tighten
Loosen
Threadtensionnut
Weaken Strengthen
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
①
②
Thread
Opener
Loosen Tighten
Threadtensionscrew
—8 —

C Adjustment of the thread take
up spring
1 . Adjusting movable range of the thread take
up spring
( 1 ) Toadjustthethreadtakeupspring①for
theleftthread,loosenthestopperstopscrew
② andmovethestopper③.
 Note:IncaseofLU2-4710,adjustonlystep(1).
( 2 ) Toadjustthethreadtakeupspring④for
therightthread,loosenthestopperstop
screw⑤andmovethestopper⑥.
2 . Adjusting intensity of the thread take up
spring
( 1 ) Leftthread:
 Loosenthelocknut⑦,andremovetheface
plate.
 Loosenthescrew⑪inthearm.
 Turntheadjustingshaft⑧.
 Afteradjustment,tightenthescrew⑪ ,and
tightenthelocknut⑦.
 Note:IncaseofLU2-4710,adjustonlystep(1).
( 2 ) Rightthread:
 Loosenthescrew⑨,andturntheadjusting
nut⑩.
 Afteradjustment,tightenthescrew⑨
D
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.
HOW TO USE
HOW TO USE
Decrease
Increase
⑤
②
③
⑥
⑨-Rightside
⑧-Leftside
⑦-Leftside
④
⑪
①⑩-Rightside
Tighten
Loosen
Rubberplug
Matchingmark
Alternatingstroke
adjustingdial
—9 —

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.
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.
HOW TO USE
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
—10 —

E 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.
F 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
Specialscrew
Nut
Redmark
(positionat6mm)
HOW TO USE
Instantalternatingswitch
Alternatingstrokeadjustingdial
Stopperscrew
Nut
—11 —

G
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Ⓒ.
H 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.
—12 —

I 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6mm.
( 2 ) LoosentwoscrewsⒶ,andremovethelink.
( 3 ) LoosenallscrewsⒷ,Ⓒ,Ⓓ.
 Note:Becarefulnottodisengagethelarge
gearandthesmallgear.
( 4 ) Lifttheneedlebar2.4mmfromthelowest
position.Refertotimingmarksshowninthe
gure.
( 5 ) 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.
( 6 ) TightenscrewsⒷ,Ⓒ.
 Note:BecarefulnottoovertightenscrewsⒸ.
( 7 ) 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.
( 8 ) Movethetipofthehooktotheneedleside
byturningthepulley.
( 9 ) InstallthelinkwiththescrewsⒶasbefore.
(10) 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
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Ⓒ
Link
ScrewⒶ
SetScrewⒹ
—13 —

J
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
—14 —

HOW TO USE
HOW TO USE
K
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.
L
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.
Timingbeltpulley
Timingmark(arrow)
Blacklineonbossoflowershaftbearing
Timingbelt
Approx.0.2mm
Opener
Openerholder
ⒶScrewⒷ
—15 —

M Relationship between the
needle motion and the feed
dog motion
( 1 ) Setthestitchlengthto“0”onthefeedlength
settingdial.
( 2 ) Settheneedleatthelowestposition.
( 3 ) Leanthemachineheadbackward.
( 4 ) Loosenthefeedrockshaftcranksetscrews
Ⓐ, Ⓑ.
( 5 ) Adjustthedistancebetweenthepressurebar
andthevibratingpreventionbarto10.5mm
andfullytightenthefeedrockshaftcrankset
screwsⒶ, Ⓑ.
 Atthistime,checkthattheneedleentersthe
holeatcenterofthefeeddog.
 Note:Becarefulnottotouchthefeedrock
shaftcrank(right)andthebedtogether.
HOW TO USE
Link
Needlebar
Vibratingpreventionbar
Pressurebar
Feedrockshaftcrank(right)
10.5mm
ScrewⒷ
Needlebarrock
shaftcrank
Feedrockshaftcrank(middle)
ScrewⒶ
ScrewⒷ
Feedrock
shaftcrank(right)
Link
—16 —

N Safety clutch
●Asafetyclutchisinstalledtopreventthe
hookortimingbeltdamageifthethreadis
caughtinthehookwhenthemachineisloaded
abnormallyduringoperation.
1 ） Function of the safety clutch
( 1 ) Whenthesafetyclutchfunctions,thetiming
beltpulleywillbefreed,andthelowershaft
rotationwillstop.Theuppershaftonlywill
rotate.Stoptheoperationofthemachine.
( 2 ) Completelyremovethethread,etc.caughtin
thehook.
( 3 ) Turnthebushingbyhand,andcheck
whetherthelowershaftrotateslightlyand
properly,theninstalltheclutchdeviceas
before.
2 ） How to set safety clutch
( 1 ) Whilepushingdownthepushbuttononthe
oppositesideofbedwithyourlefthand,turn
thepulleyslowlywithyourrighthandaway
fromyouasshowninthegure.
( 2 ) Thepulleywillbestoppedbythegearplate,
butturnthepulleymorermly.
( 3 ) Releasethepushbutton.
( 4 ) Theclutchdevicewillbesetasshowninthe
gure.
3 ） Force applied to the safety clutch
( 1 ) Theforceappliedtothesafetyclutchis
thesmallestwhenthewhitemarkofthe
eccentricpinfacesthecenterofthelower
shaft.Theforceproportionallyincreasesas
thewhitemarkfacestheoutside.
( 2 ) Toadjusttheforce,slidethetimingbelt,
loosenthesetscrew,andturntheeccentric
pin.
( 3 ) Afteradjusting,fullytightenthesetscrew.
HOW TO USE
HOW TO USE
Pulley
Pushbutton
Bushing
Timingbeltpulley
Safetyclutch
Gearplate
Lowershaft
Strengthen
Whitemark
Eccentricpin
Eccentricpin Timingbelt
Setscrew
Weaken
—17 —