Husqvarna 6690 User manual

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SERVICE-ROUTINE
6690
Husqvarna

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Directions for use
Theseserviceinstructionsareintendedtobeused
byserviceworkshoppersonnelorbysalesmenwho
carryout servicing intheirowndistricts themselves.
Theyassume athoroughknowledgeof thehandling
of precision appliances and accessibility to service
tools.
Themanualisdividedintothreesectionsand
includesall servicepoints and checks which should
becarriedoutduringa complete overhaul of a
sewingmachine.The first sectionincludesthe
controlof the a equate functioning of integral details.
Thesecond section deals with the various settings
which mustbe maintainedto ensurethat the
machinefunctions in a satisfactory way.
Thethird sectiondealswithdismounting, mounting
andsettingtheelectronic units included inthe
machine.
Thediagramsonlygiveanindicationastowhere
thedetail or mechanism mentioned is located in the
machine.Formoredetailedinformationregarding
theconstruction, etc., refer to thediagramsinthe
sparepartslist. The codings of the details referto
thesediagrams-as an example, detail 5/37 can be
seen in the spare parts list on page 5, pos. 37.
Contents Page
Visualcontrolofdetails 3-9
Settinginstructions 10-29
Electronicunits 30-44
Thefollowing details shouldbevisuallychecked
See page
Stitchplate 3
Presserfoot 3
Feed dog 3
Bobbin case 4
Hookcover 4
Hook 5
Driver 5
Cog belt 6
V-belt 6
Reductiongear 7
Terminalboard 7
Motor 8
Footcontrol 9

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The stitch plate
Thestitch plate must not be damagedinanyway.
Particularattentionshouldbe paid to possible
damageor unevennessaroundtheneedle hole.
Action
Exchangethe damaged stitch plate.
Spare parts: See RA, page 4.
OrderingNo:Stitchplate: 4115628-01.
Presser foot
Requirements
Thereshould be no scratches ontheundersideofthe
presserfoot.
Action
Exchangethe presser foot if there are scratches on the
underside.
Comments
Howthefabricisheldbetweenthepresserfoot and the
stitchplate plays an important roleinthestitchformation.
Spare parts: See RA, page 22.
Ordering No: Zig-zag presser foot 411 1383-01
Utilitystitchandpatternpresserfoot411 4512-01.
The feed dog
Requirements
Theupper side of the feeddog (10/1) must notbe
damagedin any way, e.g. broken teeth, etc.,and
should befreefromfluffandpiecesofthread.
Action
Thefaulty feeddogshouldbe exchanged.Removethe
stitchplate. Undo the screws (10/2) and remove the feed
dog. As regards the setting of the feed dog in relation to
thestitch plate groove, see page 23.
Spare parts: See RA, page 10.
Ordering No: Feed dog 411 5910-01.
Upper side Underside
Zig-zag presser foot 411 1383-01
Utilitystitch andpattern
presser foot 411 4512-01.

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The bobbin case
Fabricdressing may fasten under the thread tension
springand cause the thread tension to change.This
canbe removed by means of a needle, which should
beinsertedbetweenthe spring and the bobbin case.
Spare parts: See RA, page 9.
Ordering No: Bobbin case 401 1530-02.
Depositsfromthefabricorthreadcan fasten on the
spindleofthehookandcause noise. If such is the
case,the spindle shouldbecarefullycleanedwith
thebrushin the accessory box. At the same time
makesurethatpiecesofthreadwhichhavebecome
woundround the spindle are removed.Inbadcases,
exchangethe bobbin case.
Spare parts: See RA, page 9.
Ordering No: Bobbin case 401 1530-02.
The hook cover
Requirements
Theinsideofthe hook cover must not be
damaged.Bothaxial and radial movement
shouldbepossible.
Action
Exchangethe hook cover if it isdamaged.
Checkthat the holes in the hook cover are not
blockedand that the shoulder screwsandthe
holdersarenot damaged. Regarding the gap
betweenthehookcoverandthedriver,see page 21.
Comments
Theinsideofthe hook cover makes a support for
thehookandthe bridge above the finger of the bobbin
casesupportsthethread,sothatthethreadloopis
formedontherightsideoftheneedle.Thepossibility
ofmovementinthe hook cover is a prereguisite to
avoidunnecessary noise.
Spare parts: See RA, page 9.
Ordering No: Hook cover 411 6662-01.

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The hook
Requirements
Thehookmustnotbedamaged.Specialattention
shouldbegiventoseethatthetiphasnot been
damagedor worn, causingburrsorunevenness.
Action
Exchangedthe damaged hook.
Spare parts. See RA, page 9.
Ordering No: Hook 401 1521-01.
The driver
Requirements
Thesurface of the driveragainstthehook must not
bedamaged, wornorunevenin any waywhich
mighthinder the passage of the thread.
Action
Thedamaged driver (9/10) should be exchanged.
Turn thehandwheeluntil theneedleisatthe highest
position.Theslotinthedriverisnowinthe middle,
underneaththe feed dog.Undothethree screws
(9/16)which holdthehookcover-remove the
hookcover andthehook. Then undothethree
screws(9/11)inthedriver, and exchange it for
anewone.Notethepositionoftheslotin the
driver.Thereafter “Thedistancebetweenthe hook
andtheneedle”shouldbecheckedaccordingto
page21,“Thegapbetweenthe hook cover and
driver”according to page 19, and“Setting the
timingforthe hook in relation to the needle”
according to page 20.
Spare parts: See RA, page 9.
Ordering No: Driver 411 6415-01.

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The cog belt
Thebelttensionshouldnotbesoloosethatitpermits
slippingwhenthemachineislockedandthefoot
controlisdepressed.Tightertensionmakesmore
noise.Thebelt should not be damaged.
Adjustment
Thescrews (14/8, 9) in the reduction gear holder
areaccessibleby means of two holes inthelarge
cogwheel (14/29). If both the screws are loosened,
acertainadjustmentispossiblebymowingthe
framefor the cog wheel journal (14/20, 25, 26)
oneway ortheother.
Tightenthescrews.
Spare parts: See RA, page 14.
The V-Belt
Requirements
Thebelt tension should not be too tight or too
loose.Theslightestamountofslippingis
permissiblewhen the handwheelisheld
firmlyand the foot controldepressed.
Adjustment
Thescrews(14/8,9) in the reduction gear
holderareaccessible by means of two
holesin the large cog wheel (14/29) If
boththescrewsareloosened,acertain
adjustmentis possible by mowing the
reductiongear.
Spare parts: See RA, page 14.

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The reduction gear
Somechange inthesoundlevel when usingthe
reductiongearisnormal. The gear should be
exchangedonly if thesounddeviation is very
noticeable.
Dismantling
Setthe thread take-up lever at the lowest position,
removethe handwheelandthen takeawaythebelt
guard,printed circuit and cog belt. Unscrew the
screw(14/12)inthebase plate and loosen the
screws(14/36) in the holder (14/6). The
screws(14/8,9)in the reduction gear are
accessiblethrough the holes in the large
cogbelt wheel.Removebothscrews, turn
theholder and liftoutthereductiongear.
Mountingofthereduction gear is done by placing
theframe(14/20)insidetheholderandscrewingin
thescrews (14/8, 9). Replace and tighten the screws
(14/36,14/12).Checkthatthestar lock washer is in
place(14/35)andcheck the tension. Replace the
beltguard andhandwheel,makingsure that the
threadtake-upleverisatthelowestpositionand
themetal latchonthe handwheelpointsupwards.
Spare parts: See RA, page 14.
The terminal board
Checkall connections and cables.
Ifthereisinterferenceinradio or television
receptionfrom themachine,exchangethe condenser.

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The motor
Control of function
Thefunctioning of themotorcanbe checked without
dismountingtheprintedcircuit.Useaspare part circuit
andconnect it to the connections on theterminalboard
andtest the machineintheordinary way.
Themotornoiseisaffected by the load and the belt
tension.Only motorswhichhave anoiselevel
considerablydeviating from normal shouldbe
exchanged.
Dismantling
Setthe thread take-up lever at the lowest position,
removethe handwheelandthen takeawaythebelt
guard,rearcoverandthecogbelt.
Pullout theplugbythe motor andremovethe
screws(5/16)in the base plate; fold under the
connectionterminal board.Thenremove the
screws(14/36)inthe holder of the reduction gear
andlift out the motor. Mounting is done inthe
reverseorder.Checkthebelttension.Replace
andfasten the rear cover,beltguardand
handwheel,makingsurethat thethread
take-upleverisat the lowest position and that
themetal latchonthe handwheelpointsupwards.
Spare parts: See RA, page 16.

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The foot control
Requirements
Thespeed shouldbecontinouslycontrollable from
100 r/min to full speed.
Theconnectors to boththewallsocketand the
terminalboradmustnot be damaged or deformed.
Action
Testthe foot controlonamachinewhich is known
tooperate normally.
Ifa satisfactory result is notobtainedexchange
the faultyfootcontrol.
Ifthe cable or plug are damaged, exchange the
damaged part.
Spare parts: See RA, page 17.
+20
-0

10
Setting instructions
The best results will be obtained if you make the
Settings in the following order at each service.
Contents See
page
Setting ratings 11
Gauges 11
Service tools 12
Arm shaft.
Axialplay 14
Lower shaft.
Axialplay 14
Arm shaft circuit.
The zig-zag movement of the needle 15
Needle bar frame.
The setting of the needle at right
angles to the feeding direction 16
The setting of the needle in the
feedingdirection 17
The stop, needle bar frame 18
Thehook.
The distance between the hook
and the needle 19
The timing of the hook in relation
to the needle 20
The gap between the hook cover
and the hook 21
The needle bar.
The upper position of the needle 22
The feed dog.
The stitch plate 23
The position of the feed dog in
relation to the stitch plate groove 23
The lateral setting of the feed dog 24
The height of the feed dog 24
The setting of the feed dog in
relation to the needle 25
Lowering of the feed dog 25
The presser bar.
Tangentialsetting 26
Presser foot pressure 26
Upper thread tension.
Thread tension release lever 27
Setting the thread tension knob 27
The thread take-up spring.
The spring force 28
The adjustment casing 28
The lower thread tension.
The thread tension of the bobbin case 28
The stitch length
The balance between forward
and reverse feeding
Buttonhole 29