Bengtson Company Sopwith Camel 1/9th Scale User manual

SopwithCamel39.2”
Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
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SopwithCamel1/9Scale39.2”
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R/CScaleModelInstructions
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CONTACTINFORMATION
DesignedbyM.K.Bengtson
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ManufacturedandDistributedby:
BengtsonCompany
e‐mail:[email protected]
www.aerodromerc.com

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Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
Sopwith Camel 1/9th Scale
Thankyouforpurchasingthe1/9thScaleSopwith
Camelmodelforelectricflight.
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THEMODEL
The1/9thScaleSopwithCamel,thismodelisdesigned
tobeeasytobuildandexcitingtofly.
ModelSpecifications
Morethan350lasercutparts
Scale:  1/9
Prop:  10x6
Channels: R/E/A/T
Wheels: Balsa&plywood,Neoprenefoamtires
Wingspan: 39.2ʺ
AirfoilType: Flatbottomed
WingArea: 460sqin
Cowl:  Builtupbalsaandplywood
Weight: ~28ozreadytofly
PowerSystem:AXI2217/20
Designer: M.K.Bengtson
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BUILDINGTHEMODEL
BeforeStarting
Anoteaboutthephotos:Thephotosweretakenofa
prototypeandthepartssuppliedmaylookslightly
differentfromthem.However,theconceptsillustrated
arethesame.
TheSopwithCamelprototypeswerebuiltbySam
LeonardandTimKwasny.Thefollowingisacompilation
oftechniquesfromthemandotherbuilds.AerodromeRC
appreciatesthecontributionsofthesetwobuilders.
WINGS
Buildthetopwinginonepiece.Notethatthetrailing
edgesare1/32”plywoodandaresuppliedinthekit.The
leadingedgesare1/8”diameterwooddowels.Miniribs
arealsoincluded.Putsmallscrappiecesof1/8”balsaon
thenotchesintheribsthataccepttheIPstrutstoserveas
reinforcementsandasabaseforcoveringlater.
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Buildtheaileronsandsandtheleadingedgetoshape.
Choosearoundedshapeforcenterhingingorabevelled
shapefortophinging.
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Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
Hereisthewingtip.
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Aileronservosareattachedwithshortthreadedrodsto
theailerons.Aileronservosarefitinservocompartments
locatedinthelowerwingswiththesupplied1/32”
plywoodservocovers.Routeservowiresthroughholesin
lowerwingribs.Usea“Y”wiringharnessconnectorto
wiretheservostoasingleradioconnection.Alternatively,
twoRCchannelscanbeusedwhenmixedelectronically.
Ifdifferentialaileronthrowsaredesired,rotateeachservo
hornforwardabout20degrees,whilemaintainingthe
neutralpositionoftheaileron.Thisshouldcounterany
adverseaileronyaw.
FUSELAGECONSTRUCTION
Thefuselageisbuiltastwoseparateboxstructures,the
frontsheetareaandtherearbuiltupsection,whichare
thenjoinedovertheplan.Thissystemnotonlykeeps
eachstagesimple,butitalsohelpstoensureastraight
fuselage.Somemodelersprefertobuildeachside
completelyontheplanandthenjoinbothhalvesoverthe
topview.Bothsystemshavetheiradvantagesand
drawbacks.Thefollowingisthefront/backmethod.
Beginbybuildingtworearfuselageframesoverthe
planandallowtodry.Selecthardbalsaorlaminatedbalsa
forthelongerons.Adddiagonalsforarigidstructure.
Repeatwiththeotherside.Somebuildersbuildthe
secondsideoverthefirsttoinsuretheymatchperfectly.
BesuretousewaxpaperorSaranWrapbetweentheseor
youʹllnotbeabletogetthemapart.Jointhesidesoverthe
topviewoftheplanandaddthecrossmembersandtail
skidmount.Checkandcheckagaintoinsurethatthe
structureissquareandstraightoryouwillendupwitha
bananafuselage.Finallyaddthewedgeshaped
horizontalstabilizersupports.Waituntilthefront
fuselageisjoinedtoaddtheturtledeckformersand
stringers.
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Buildthefronthalfanddecking
Laythefrontsidesontheplanandgluethemtogether.
Thealignmentnotchinsuresthattheymateproperly.On
theoutsidesurfacesgluethe1/32”plywooddoublers.
Useaheavyweightandslowsettinggluelikeepoxy.If
waterbasedglueisused,warpingmayoccursoallowthe
gluetodryundertheweight.Jointhesideswiththefront
F1andbackF5formersand1/8”plyundercarriagemount
crossmembers.Addthedeckingandtopformers,and
carefullytrimtosizeandfit1/16”sheeting.Theside
cheekscanbeaddedafterthefrontandbackofthe
fuselagearejoined.Smallpiecesof1/8”balsaareadded
nexttothecabanestrutsbeforecovering.Themachine
gunareaortheCamelʹsHumpismadefromlaminated
lasercut1/4”balsasectionsJ1throughJ5.Gluethem
togetherasshownontheplanandsandtoanicesmooth
shape.

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CabaneStruts
Thecabanestrutsarefashionedusingbalsafairingson
lasercut1/8”thickplywoodformers.Theformersare
designedtomakealignmentofthetopwingeasy.Thetop
ofthecabanesformabarthatfitsintoslotsinthewing.
Balsa,bassorscrapplywoodcanbeusedtofairthe
cabanes.
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TAILSURFACES
Layoutandgluepartsofthetailsurfacesontheplans.
Elevatorandhorizontalstabilizer
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Rudderandverticalstabilizer
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Sandthetailparts,roundingoffalledges.Don’tadd
thehornsorhingethesurfacesuntilaftercoveringis
complete.
Wingsandtailfeathers.
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LANDINGGEAR
ThelandinggeararefashionedfromCAhardened1/8”
plywood.Sand,soakwiththinCAandthen,securely,
epoxythegeartothemodel.0.045”musicwireisusedto
reinforcethegear.UseKevlarthreadorstrongcarpet
threadandsecurethewirealongthegear.CAinplace.A
shockabsorbingmechanismhasbeendesignedtoletthe
modelhavealittlegivewhenlanding.Attachthe3/32”
musicwireaxletothetopsideoftheLGcrossmember
withKevlarthreadandepoxyinplace.Smallholesare
placedinthisparttofacilitatethelacingofthisthread.
Addshortpiecesof1/8”brasstubingasbearings/spacers
forthewheels.Userubberbandstoactasshockabsorbers
butmakeeachsideexactlyastheoppositesite.
Otherwise,theshockresistanceisunequalandyour
modelwillcanttoonesideoneverylanding.Adding
Kevlarcrossriggingwilldramaticallystrengthenthe
landinggear.
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COVERING
Anylightweightcoveringmaterialcanbeused.
PolyspanwithdopeorMinwaxPolycrylicmakesagood
choice,Litespanisalsopopular.
Decaloutlinesforthismodelareavailableon
www.aerodromerc.com/decalsinAdobeAcrobatpdf
formatforprintingoutondecalpaper.
WindsockDatafile“SopwithCamel“publicationhas
detailsonplacementandmarkings.
Availableat:http://www.byrdaviationbooks.com/
WHEELS
Gluingtheplysidesonthe3/8”balsacoremakesthe
basisforthewheels.Usethebrasshubforalignment.
Epoxythehubsinplaceandaddasufficientamountof
epoxyaroundthebaseofthehubtoreinforcethe
connectionofthehubtotheply.Plywoodreinforcing
hubsareprovidedthataretoslipoverthebrasstubingas
shown.Next,CAgluetheneoprenecordingtogetherto
froma“tire”.UsethinCAsparinglyastheCAbonds
veryaggressivelytotherubber.PresstheCAwettedends
togetherforaninstantbond.Thebestwaytoalignthe
endsistogluethemwhiletheyareinplaceonthewheel.
ThenattachthetirestothewheelsandCAinplace.Athin
beadofCAaroundtherimmakesforasecuretire.
Paperconesarecutout.Useaballpointpentoscore
eachlineonthebacktomakeanimpressionof“spokes”.
Itishelpfultodothisoperationonapapertabletsothat
thepenmakesagoodcrease.Foldthepaperalongthe
creaselinestoexaggeratetheraisedlines.Oneofthe
sectionsformingawedgeiscutout.Makecutstothe
centerofthecirclealongapairofthespokes.Closethe
papercutouttoformaconeandtapethejointinsidethe
cone.
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Theinsideconesmaynowbeattachedtothewheels.
Theoutsideconesmaybeattachedatthispointifwheel
collarsaretobeused.Alternatively,afterinstallingthe
wheelsonthelandinggear,awashermaybesolderedto
holdthewheelinplaceandthentheconeisattached.
Thismethodmakesaverynicescaleappearance.
COWLING
ThecowlingisofbuiltupconstructionusingC1and
C2.Constructfrontcowlringbygluing2C1’smaking
surethattheyareoverlappingcompletely.Makea
cardboardtemplatefromtheplanasaguideforsanding
thebalsaintoshape.

Thecowlshouldnowbesealed,sandedandprimed
untilnowoodgrainisleftshowing.Baby(Talcum)
powderincleardopemakesanexcellentbalsasealer.
Talcumpowdermixedinwhitegluemakesexcellentfiller
forgapsorgouges.Sanddownafteritdries.
FittingTailSurfaces
Attachtheruddertotheverticalstabilizerusing1/8”
stripsofCAhinges.Similarly,attachtheelevatortothe
horizontalstabilizer.Gluethehorizontalstab/elevator
assemblyontothefuselage.Thengluethevertical
stabilizerandrudderassemblyintotheslotinthe
horizontalstabilizer.SincetheCamelhasaveryshort
nose,pullpulltailsurfacecontrolsaremandatory.

AileronServos
Afterassembly,connecttopaileronstobottomailerons
with1/16”musicwirepushrods.Connectthemtothe
small1/16”plywoodcontrolhornsfittedinthetopofthe
bottomaileronandthebottomofthetopaileron.

FittingtheRiggingWires
UsestrongthreadorKevlarfishinglineorelastic
beadingcordingtosimulateriggingwires.Usesmall
screws,fishinghookeyes,straightpinheadsorsmall
eyeletstoattachthelines.These“wires”canaddadegree
ofstrengthtoyourmodel.
Batteryhatch
Fashionabatteryhatchfrom1/32”plywood
BalancingtheModel
Balancethemodelatthepointshown.Choosinga
largerbatteryispreferredtoaddinglead.

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Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
HereisTimKwasneyʹsinthebonesshotoftheCamel.

Andafrontview

FLYING
HereisanexcerptofTimʹsmaiden:
“WellaftermuchdelayandfrustrationIfinallyhadthe
maidenflightoftheCamelthismorning.Iamveryhappy
toreportthatitisnolongeranorganizedpileofbalsa
wood,itisanairplane.Itsfinalallupweightcamein
about36oz.withhavingtoaddabout6ozofleadtothe
nose.IamusingtheAXI2808/20with3cellLiPo’sand
8X5prop.Ishouldprobablyusea10”propbutIwas
worriedaboutoverheatingthemotor.Theplaneflewvery
wellbutseemedlikeitcouldusealittlemorepowersoI
willtrythe10X4propIstartedwithandseeifthereisany
problemswithheat.Therewasalightbreezeandit
handledthewindfine.”
AND
“Takeoffwasniceandsmooth,theplanetracked
straightandtrueonthegroundandwasairborneinabout
30ft.at¾throttle.Iclimbedoutatabout20degreesuntil
abouttwomistakesupandthendidacoupleofturns
aroundthefield.Theplaneflewniceandstableandthe
turnsweresmoothwithoutanyadverseyaw.Ineeded
justalittleupelevatortrimanditwasflyingprettymuch
handsoff.LikeIsaidinmyearlierpostIfeltitwasalittle
underpoweredbecauseitseemedtostrugglealittle
heededintothewindupatthehigheraltitude.Itested
thestallanditdroppeditsnosealittlefasterthanI
expectedbutrecoverywasapieceofcake.IthinkIwill
takealittleoftheweightoutofthenoseonmynextflight
andseehowitdose.Therewasnosignofdroppinga
wing.IdidafewlandingapproachesbeforeIgotitlined
upandthenbroughtitinwithabout¼throttle,Icut
throttleatabout4ft.andletitsettlein.Ineedtosecure
thebatterybetterbecauseIbouncealittleonthelanding
andthebatterypoppedoutandcaughtunderthewheel
andcausedtheplanetonoseover.Nodamageexceptfor
alittlescrapeonthecowl.”




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Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
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ThemodelshouldROGongrass,pavementorhard
surfaces.Themodelmayrequirecoordinatedturnsusing
bothaileronsandruddercontrol.Thisisduetoadverse
yaw.Halvingtheailerondownthrowmayreducethe
yaw.Thiseffectcanbeaccomplishedbyrotatingthe
controlarmoftheaileronservoforwardabout20degrees.
Letthemodelgainaltitudeslowlyofftherunway.
Applyingtoomuchupelevatoratslowspeedsrisksa
stall.Makeyourturnsgentlyastightturnsrisktip
stallinginanymodel.Don’texpecttheelevatortomake
themodelclimb.Thinkoftheelevatorasadeviceto
changetheattitudeofthemodel.Thewingandairspeed
ultimatelymakethemodelclimb.Oftendownelevator
appliedatstallingcanavoidamajorcrash.Themost
importantdetailsforproperflightoperationsare:
• CGlocation.Tailheavymodelsneverflywelloratall.
• Downandrightthrust
• Straightandnonwarpedwings
CONTACTINFORMATION
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