Bengtson 1/16th Scale User manual

SopwithTriplane20”
Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
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SopwithTriplane20”1/16Scale
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R/CScaleModelInstructions
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CONTACTINFORMATION
DesignedbyM.K.Bengtson
PrototypebyDaveMitchell
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ManufacturedandDistributedby:
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BengtsonCompany
e‐mail:[email protected]
www.aerodromerc.com

SopwithTriplane20”Page1
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Copyright©2007‐11M.K.BengtsonAllRightsReservedRev07/11
Sopwith Triplane 1/16th Scale
Thankyouforpurchasingthe1/16thScaleSopwith
Triplanemodelforelectricflight.
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THEMODEL
Asemiscaleadaptationofthe1/16thScaleSopwith
Triplane,thismodelisdesignedtobeeasytobuildand
excitingtofly.
Specifications
More than 200 laser cut parts
Scale:  1/16th
Weight: ~6oz
PowerSystem:GWSIPSA
Prop:  7x3
Channels: R/E/T
Wheels: BalsawithNeoprenefoamtires
Wingspan:~20ʺ 
AirfoilType: Flatbottomed
WingArea: 137sqin
Cowl:  Builtupbalsa
Decals: Availableonthewebsite
Designer: M.K.Bengtson
PrototypeBuilder: DaveMitchell
Thefollowingbuildinformationisfrompostedcomments
byprototypebuilderDaveMitchell
DaveMitchellhere,erstwhilesecretaryfortheD/C
Maxecuters.Irecentlystartedaprototypebuildofan
AerodromeR/CSopwithTriplane,19.8ʺWS,micror/c.
SuppliedtomebyAirMidiMicros.Aneatlittlebeastie‐‐
photosaswegoalong.
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TheplancallsforanIPSA,butthepropdiameteris
limitedto7ʺ,soIsuggestedanIPS2instead‐‐‐lookclose,
andyouwillseethenotationontheplan!Iʹllbeusingall
stockmicroGWSgearasperAirMidiʹsrequest,asthisis
whattheysell‐‐‐‐‐sonobreak‐the‐bank‐in‐the‐pursuit‐of‐
superlightweight‐happinesshere.R‐E‐T.Iʹmhopingto
bringitinat1g/sq.in,whichwouldpegitat137g,so
yeah‐‐‐around5oz.Thatmightbeoptimistic,butweʹll
see.Usingallkitwood,andforthemostpartfollowing
plansexceptforafewminormods.Itwilldefinitelybean
outdoorflyer.
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Itriedsomethingnew(forme)forhingingthe
tailfeathers,illustratedhere.Thefinandrudderpostsare
laminated,withafewstripsofKevlarthreadbetweenthe
laminationstoserveashinges.Workswell‐‐besuretopre‐
beveltheedgesofthepoststoallowmovement.
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StartingtolookSopwithishatthisstage.Timetostart
inonallthosewings....
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Heresheiswiththebottomwingpinnedinplace....
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WHEELS
Gluingthe1/16”balsasidesonthelaminated1/16”
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1/4”Diameter
neoprenecordingtogethertofroma“tire”.UsethinCA
sparinglyastheCAbondsveryaggressivelytothe

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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.
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.
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Hereʹsashotofoneofthelowerwingpanelonthe
board.Imadesomemodificationstotheriblayout.Kit
uses1/32plytrailingedge‐‐interesting
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Iʹmshootingfor1g/sq.in.Youʹllhavetodothemathto
translatethatintooz/sq.ft,Iʹmtoolazy!
IhaveseveralR/Caircraftflyinginthisrange,allusing
prettymuchthesameGWSgearasIwillhaveinthe
Sopwith,thoughallofthem(a28ʺHerrStearman,a
24ʺHerrPittsSpecial,anda20ʺscratchbuiltFokkerDr1)
usetheIPS‐Amotorwith9‐10ʺprops.
Finishedoffallthemwingsandstuckittogetherfora
photo.
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Andacloseup.Notetheplytrailingedgeofthewings.
Theinterplanestrutsaredesignedtoregisterthewing
spacingcorrectly.Notethereisasteponallfourstruts
thatthemiddlewingisrestingon‐‐kindofhardtosee
here,Iʹlltrytopostaphotothatshowsitbetter.Oncethe
middlewingisgluedintoplace,asecondpieceisgluedto
thetrailingedgeofeachstrut,abovethemiddlewing,to
finishoutthestrutprofile.
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Wirelandinggearinplacenow,andeverything
sandedup.IhavedecidedtocoverherwithLitespan,
whichisamaterialIhavemixedfeelingsabout,butI
thinkitwillbegoodforthisbird.Itistougherthantissue,
whichisafeatureImayneedgiventheplaneʹsrelatively
highexpectedwingloading.SoIspenttheevening

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brushingtheframeworkwithBalsalocandgettingallthe
littlebitsinplace.
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Anotherview.Thebatterywillbelocatedinbottomof
thenose,betweentheLG.Ihadoriginallythoughttousea
350mah2SLipoly,butIamthinkingnowalittlesmaller,
tosaveabitofweight.Wewillseehowitbalances....
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ProgresscontinuesontheSopwith....nearlydone.I
havechosentofinishherinFrenchmarkings,aircraft#10
locatedinDunkirk,1917.Photoevidencesuggeststhat
thisaircraftactuallyfeaturedthelargetailplaneofearly
Tripes,butWTH.
IcovereditwithLitespan,asplanned,butIwoundup
makingtissue‐and‐Litespaninsigniasandmarkings,
appliedwithFuturefloorpolish,workedprettywell.The
noseiscoveredwithaluminiumleaf.
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Landinggearandwheelson.....andapaperClergetin
thenose.Ipluggedherintoday,ranthemotorupand
checkedallthecontrolsurfaces.Afewmoredetailsand
someriggingandsheʹsreadytogo!
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Anotherview.WhatagreatdesigntheSopwith
Triplanewas!
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Anothershot,inthemorningsun.Ijustneeda
machinegunandatailskidnow,andtoworkupahatch
forthebattery

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HereisanexcerptfromDaveʹsMaidenflightreport:
“IgottoflytheSopwithTriplanetoday.Lightbut
slightlygustywinds.Firstflightswereunpleasantlyhairy‐
‐twitchyandovercontrolled.Idialedbacktheservo
throwsandfedinabitofexponentialforthestab,and
thingsgotbetter,butitwasstillnotideal.ThenIputina
larger(350mah)batterypack,whichmovedtheCGupa
bit‐‐‐ahhh,nowweʹregettingsomewhere.IthinkIwill
needtodropinanother5gorsoofweightinthenose.I
hadinstalledaGWSIPS‐2motor,withaGWS7060prop.
YoucouldprobablyfallbacktoanIPS‐Amotor,withthe
sameprop‐‐‐IhadwaymorepowerthanIneeded.Very
sensitivetocontrolinput,especiallystab.Sheʹsnotfora
beginningflyer,andsheʹstoohotforindoorsunlessitʹsa
bigsportsdome,butshesurelooksneatintheair....Iʹma
happycamper“
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CONTACTINFORMATION
Distributedby:
BengtsonCompany
e‐mail:[email protected]
WebSite:www.aerodromerc.com
