All about Electrics

The author provides six rules thumb will help achieve what calls Electric Elation boot theres lots information con structing models have lots strength needed much strength weight its needed techniques helpful kinds modeling Part 8 about Bob Kopski THIS IS CONTINUATION topic begun last month what flies previous issue described detail makeup per formance four Electrics specific designs covered real message Part 7 nothing magical about particular examples planes similar makeup should fly com parably Now going cover some general ized rules thumb electric power some construction suggestions purpose further tie together earlier information help assure first-time continuing Electric successwhat call Electric Ela tion Rule thumb number have stated repeatedly extremely important con sideration determining flying quality Electric weight promised show quantitatively Motor Power Input Cruise s oz x oz/sq planes Another convenient equivalent way express Watts ht lbs x Wing Loading oz/sq ft rule thumb empiricism fitted expression carefully con trolled flight experiments Several comments order First note units make normal sense Watts same ounces squared divided sq dont let bother Also power input power volts x amps motor observed static condition something can measured bench Further expression applies nominal airplane reasonable design outfitted appropriate motor battery propjust kind plane people would like fly Lets take example Remember Sport Scale J-3 discussed last month rewarding flight maneuvers model simple realistic cruising level flight power required P 68 X 681700 about 60 watts Does really work Yep established marking throttle control position transmitter plane cruis ing level flight measured elec trical power input throttle setting bench did several times Another technique used established above equation choose plane good climb rate proceed add weight CG until sustained level flight cruise same power achieved did several times several different planes Results two methods always agreed closely Ponder bit note indeed very useful information effect allows know ahead time plane going fly relationship can also used determine what kind bat tery needed fly such-and-such plane long done using infor mation earlier parts series some coming up shortly wants just cruise around Im sure Thats point way because power beyond cruise power level will cause plane climb cruise condition used convenient condition measurement because cruise something can achieved observed repeatedly climb rate much tougher ascertain course cruise used discussion condition plane just maintaining level flight observed low enough altitude assure indeed level flight Also level flight does mean constant level screamby aerobatics Now weve set stage lets get real point power required battery cruise proportional models weight squared planes Youd better back up read again means example 10% crease weight requires about 21% crease power same nominal flight April 1984 77 Household scales very helpful getting know Electric will fly left has 16-oz range making useful during model construction keep tally quarter ounces scale four S-22 servos pointer 2% oz About half total weight finished Electric shown resting larger scale Astro 40 Cobalt 14 12 Ah cells come 2 lb 10 oz wiring installation will add another 1 2 oz making total power system about 44 oz finished plane should weigh about 5% lb performance Example 30-oz model needs 3 oz added to suffer re duced motor run time over one-fifth some powered flight performance Three 16 oz servos instead three O6-oz ones will should now clear quantitativelythat weight very impor tant Weight sensitive parameter cause multiplied itself determine well long Electric will fly Friends watch out quarter ounces Rule thumb number two motor input power battery drain required ROG takeoff about 30 50 watts per pound nominal airplane lot variables involved thats theres such spread possible range power values Again guideline empiricism describes results Ive over several years several planes general planes lighter wing load ings larger wheels good runways glider wing structure similar text description Main stub spars hard balsa doubled sides square spruce stock Webbing spruce doublers end staggered lengths providing small steps strength weight reduction along span vertical balsa filler front TE ends before gets tip TE rear cap added after otherwise-completed wing panel removed workbench Block-sand sheet balsa joint hold glued cap position strips masking tape Afterwards remove tape round edges cap sketch planking dihedral omitted clarity need less power get off Models small wheels plush spring grass need much power true no matter what powers model electric motor effect start ground roll static thrust motor/propeller must sufficient get wheels moving delivered power must sufficient accelerate plane speed adequate lift-off course desirable fly plane off ground horse air Lets look example J-3 again gross weight 4 lb plane has thick flat bottom airfoil light wing loading large 3-in balloon wheels normally flies very slowly easily gets off field conditions predicted power requirement takeoff 4 pounds x 30 watts/lb about 125 watts Astro 15 belt-drive speed reducer Top Flite 12-8 wood prop has power input about 160 watts full throttle takeoff easy course some headwind always helps planewhether plane Elec tric Gasbut 1-3 doesnt need Another example support rule thumb older plane Superkick name long complicated story dont ask Superkick design derived popular Falcon 56 has stretched wing 68 otherwise con forms Falcon force setup course structure bears no resemblance kit aspect customized Elec tnc Superkick flown controls motor elevator rudder Motor con trol servo-driven OFF-LO-HI Motive power older version Astro 25 16 12 Ah cells 9-6 Top Flite wood prop All-up weight 81 oz wing loading about 17 oz/sq ft plane has steerable nose wheel handles very well ground almost always takes off although sometimes little body English needed Lets test rule thumb Superkick uses NACA 2412 Falcon semisymmetrical airfoil has relatively heavy wing loading relatively small wheels 21/4 in three places model neither taxies nor lifts off easily 1-3 its reasonable expect proportionately higher power needed get off Using numbers 5 lb 50 watts/lb get predicted requirement about 250 watts Nominal operating conditions electric motor system described 250 280 watts inputjust right course rule thumb can ex tended fit other examples beyond two given sense somewhat flexible guideline however pect ground handling takeoff per formance Despite meeting suggested guideline conditions some planes power sys tems may just too small typical outdoor flying conditions As best can tell about smallest power system can assure reliable ground handling takeoff around 150 watts Yes excep 78 Model Aviation tail structure made 3/32 sheet balsa per text picture MonoKote covering has dusted talc reduce glare highlight tape edges Continuous tape strips used rudder elevator hinges look closely bottom rud der Center end elevator may see edges iron-on cloth reinforcements toughens balsa surface vicinity control horn attachments Scotch brand Plastic Tape has proven practical hinging material Electrics thousands flights o 1-4 SPRUCE DOUBLERS END o 1-2 STUB SPAR PAIR -EXCEPT BOTTOM PIECE EXTENDS OUTWARD D 1-2 WEBBING ENDS tions Playboy about 90 100 watts onemost time Anyway lot depends specific field conditions wheels etc Please take offerings herein what really composite experience-backed guidelines should least put ball park now mumbling some thing about dickens youre supposed know much power goes motor prop battery After two rules thumb dont mean much youre missing power information Hang tight gang know well survey soon Rule thumb number three guide line requires electric power system components make up about half total weight RC Electric As other parameters also has some tol erance Reasonable limits range 40% 60% Several examples described Parts 5 7 Rule thumb number four wing largest area component models Ive singled out its very own guide line wing Electric RC model should weigh about 2 oz per sq ft Reason able limits 18 22 oz per sq ft lower limit typical smaller gliders upper larger limit applicable aero batics suggested weights complete wing structures including ser vos landing gear components working guideline helpful know Super MonoKote weighs about V4 oz per sq ft remember covered area twice wing area No Im familiar other covering weights Implicit guideline wing weight simultaneous need adequate strength have learned hard way use typical modeling materials make wings other components both light strong some information difficult put words well give try bit later meantime assured lightness does necessarily mean weak ness Rule thumb number five time Think terms quarter ounces four make up ounce four make up quarter pounder may bit overbearing now very important have witnessed disappointment too-heavy plane no need happen Think light Ive acknowledged Electrics heavier other types models also insist Electrics quite flyable ever must part help assure success Simply put must make up some weight electric system components using well-considered con struction techniques quite pos sible generally some self-discipline breaking bad habits may re quired Rule thumb number six comes tough Forget kits Spar details sketch similar Euphoria Two acrobatic model weighs 58 oz has wing 50-in span 9Yz-in chord Among its repertoire inside outside loops very fast roll very strong lightweight structure has gradually-stepped strength weight reduction along span Spars boxed inside semi-symmetrical ribs bump-free covering surface Center planking dihedral details omitted clarity spar structure 3/16 light balsa core capped 3/16 sq spruce near root hard 3/16 sq balsa outward Note staggered transition points spruce-to-balsa caps Spar sides reinforced 1/64 ply center ending outward-staggered points Ribs 1/16 balsafirm root lighter outward aileron actually hollow capped balsa triangular structure resulting cutting along length hollow TE assembly Plastic tape hinging very easy install Position covered surfaces 1/32 1/16 apart allow bind-free operation cover side continuous strip tape half width surface Before applying tape make sure covering material firmly adhered wood beneath ittoo late apply heat after tape place Add few tape doublers other side sticky side inward touches sticky side first tape gap area snap hinged surface can folded back itself along first tape hinge line otherwise fold tape strip over thin metal strip sticky side out insert author uses tape doublers near root tip movable surface two along length depending upon size plane Nobody ever likes hear fact everyone has developed bad life however kits designed habits such kits virtual lumberfor glow engine power Over years glow busses worse foam farms see engines have grown tremendously power usually doesnt matter too much output given displacement along Continued page 80 Modified box fuselage assembly has open structure top bottom aft wing loca tion typical structure has 1/16 sheet sides 1/8 sq strip vertical stiffenersstopping top bottom sheet After sides joined rear 1/16 x / cross strips added verticals top bottom Lengths 1/16 x added along four edges cap side sheeting verticals cross braces partially Finally 1/16 x /4 strips laid flat cap vertical cross strips multi-piece structure very light strong easy CyA glue Dont let complicated description scare trying April 1984 79 fA- P [/32 1/16 PLASTIC TAPE FULL LGTH STICKY SIDE USE THIN METAL STRIP TOTRIM OF F AFT PUSH FOLD UP TO TOP TAPEINSTALLATION 2-4 PLACES -r cUijriccIic] 322 So Gallatin RdMadison TN 37115 615 868-6811V Mon thru Sat 900am 500pm FUTABA RADIO SALE~k Because care REPAIR SERVICE FOR AIIradiosystemsar0prBchBCk0df& S proper operation prior shipment RADIO SYSTEMS HOBBY LOBBYFP-713K 72FM5-128 Iist$38995$24 FUTABA ROYAL E K LOG CT RO LFP-70K 72AM5-281ist5359SS. $22500 FUTABA T EP-SOK 72FM 5-128 IistS3l99$. $20 00 ACCESSORIES FOR TP-50K 72AM S-28IistS2899$ . 50 HOBBY SHACKFP-4LV$13 S-28servosIist$19995. $11500MOST RADIOS ROYAL LINEAdd $295 Prepaid Mastercard Visa COD $495 Tenn residents add 575% tanVISA WILLIATMSACCESSORIS BROTHERS ________________ 4 PILOTS STANDARD TSMANinfu WHEEL NG TARY VINTAGE TH BALLOON EN AGE 4 ENGINES PRATT & WHITNEY HT HONE PARTS HITNEY HONE PRAtT WRIGHT E GUNS LEWISVICKERS DAU BELILIM SEND $1 FOR FULLY ILLUSTRATED CATALOG4LJAa DEPT MA 1 u IAWNEE ST SAN MARCOS CALIFORNIA 92069 glowan extra pound two often goes un noticed Its easy change nitro level tank size engine size Elec tric So youll need forget kits As might expect excep tions Some kits especially gliders adapt fairly easily electric power majority kits readily convert Electric lots kit designs look like excellent candidates quiet mo tivation Thus have some favorite glow-engine kit plans wonder Elec tric version would possible just pay tention series have desire convey enough insight information reasonably-skilled modeler can deter beforehand what needed assure Electric success other extreme some kits intended Electric have per sonally seen several including Astro Porterfield Astro Sport shoulder-wing ver sion Leisure Playboy Larry Jolly Electricus Youd have work hard go wrong few other kits Electric dont have upfront familiarity cant com ment Paradoxically relatively few kits ever-increasing number fine Electric model designs appearing modeling magazines Ive personally seen several perform fly very well course must scratchbuilding nature Sometimes good magazine design becomes kit Porterfield example understand Wasp its way being kitted As what I nearly always design build scratch Lately however Ive taken interest some kits modifications might needed con vert good Electric models Some Construction Guidelines Now weve seen hard data vital statistics rules thumb planes fly well lets look beneath covering see theyre put together Lets start wing tend divide three groups gliders aero batic flying other kinds flying Electric-powered model glider wings can have similarities differences Sailplanes Both types have relatively high aspect ratios Electric glider must support mass power installation Sailplane must tolerate tow air foil can favorite either case Covering can same Whats really different Weight Some weight Sail plane less wont really matter times planes ballasted way Electric chal lenging difference Lets get some details tend avoid discourage plugtogether wings obviously makes large Electric gliders bit problem What comes down chosen design wont fit family buggy singlepiece wing must made piece will have weight Continued page 82 80 Model Aviation fL15 FULL LINE METAL SPECIALISTS penalty several ounces can mod erated bit wont have tow loads contend hardware associated holding wing parts together can lighter size weight Unfortunately personally dont have hands-on exam ples area can offer observation generalization Ive seen fair share wings fold failure almost always near wing center exactly what expect bending moment greatest obviously thats place invest some weight strength follows made near-center region super strong next failure location would further out just past super-strong part failure would less apt happen because bending moment less wing center could simply make next region part past super-strong center lust very strong next possibility fail ure would occur further out wing panel discussion has treated discrete regions wing should clear effects really gradual nature really should thought steps effect what really needed wing structure having relatively smooth variation strength weight super strong very middle very little strength tip What Ive said hardly new stuffs known seems forever prac ticality matter its much easier build wing relatively uniform strength along span gradually di minishing strength simpler wing heavier thats what about build glider wings some others well step-wise varying strength technique gradually reduce wing strength weight root tip series small steps simple compromise between virtually no variation smooth tapering variation latter can ex tremely tedious time-consuming build step-wise approach easy understand though cumbersome describe words wings usually all-balsa root tip supplemented varying-length spruce additions balsa leading edge eable soft trail ing edge usually hollow-triangle type made sheet balsa top bottom filler strips between ribs front rear trailing edge capped simple balsa strip except near center spruce cap used tolerates wing rubberbands much better So far theres nothing unusual big difference comes spars make hard balsa rectangular cross section As now common practice spruce two laid flat top bottom ribs near point maximum thickness Vertical-grain balsa webs installed tween top bottom spars along entire span legitimate Continued page 166 82 Model Aviation SUPERwings DIVISION OF HI JOHNSON MODEL PRODUCTS 11015 GLENOAKS BLVD PACOIMA CA 91331 SAILPLANE COMPONENTS CREATE YOUR OWN SUPER GLIDER WING FOAM CORES Floater Thermal & Slope FUSELAGES LUSTROLEEN 2 Meter Standard Open & Scale STAB FOAM CORES Rudder & Fin Cores COVERING MATERIALS White skin & Lustroleen WING RODS Wing Tongue Kits FOR HI JOHNSONS PORTFOLIO PRICE SHEET & ORDER FORM about sailplane construction & design using foam & plastic SEND $250 CHECK OR MO CA RES ADD SALES TAX enough clearance properly strike pro peller am enclosing two photographs showing different methods starting method flip engine forward having compression set pro peller blade two oclock position slapping propeller extremely hard engine starts flip Another method flip engine backwards strik ing propeller very close hub propeller must set horizontal parallel ground method produce satis factory results Certainly pilot must job bringing plane substantial speed getting out pits back air shortest possible interval time certainly cannot emphasize impor tance thorough complete practicing improve overall race times Know racing-circle markings Finally find competitors mark off standard circle AMA specifications use practice cases flying school parking lots etc impera tive use either chalk spray paint owner will allow mark off proper center circle landing circle pitting area Practicing under standard circle conditions improves relationship between pilot pitman since landings takeoffs done same circle atmosphere will used under competitive situa tions NEW Tartan Twin Muffler Set Allows adjustment carb running $3995 400 RPM increase over stock As always comments solicited appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Electrics/Kopski Continued aoe 82 weight saving quarter ouncing because wings dont fold tips Two additional balsa spars used top bottom about halfway between main spars trailing edge latter spars can partial span so-called stub spars Like main spar pair stub spars also webbed part length Usually bottom spar stub pair continued full span supporting ribs use stub spar seems like obvious extension now-common main I-beam some reason commonly used departure established prac tice light easy adds great deal strength high aspect ratio wings stub spars may bit unusual big difference comes now four spars get spruce doublers staggered length beginning root extending outward along main panels stopping dif ferent rib stations minimizes amount comparatively heavy material putting its strength will gooddistributed step-wise center outward Most Sailplane wings sim 3-FUNCTION ACCUETACH ITM Lb LCD Tachometer w/dual scale capability lOX bOX @ Digital Voltmeter load /5 && checking/cycling TX/RX battery combos ACCU-TACHI torquick charging operation w~9 7 9aitt Send check Noror money order Ca t add 600 tax PO Box 70956 AVIONRSS Sunnyvale CA INC94086 ply use spruce way sparstrue indiscretion true overkill inverted quarter ouncing Lets describe example Its Spec tra Soar wing 8-in chord 67-in span rectangular planform poly dihedral main panels 20 long tip panels 13 ribs spaced 21/2 relatively light Ak balsa four hard balsa spars Vt X /4 main pair goes full span although balsa used tip panel spars also rela tively light stub spar structure 121/2 long five ribs main spar webbing covers four ribs stub spar webbing three spruce spar doublers square glued alongside balsa spars bottom main spar doubler five ribs long top four ribs long bottom stub spar doubler three ribs long top two ribs long particular example spruce doubler spars located TE side balsa spars full-depth Vik ply wood dihedral barces 2-in length glued spruce pieces form super strong center dihedral joint short dihedral brace also used behind balsa leading edge wing center planked over rib bay panel iA6 balsa top bottom done before dihedral joint made allowing mating surfaces snded flat tight fit maximum spar planking end-grain contact produce truly strong dihedral Continued page 168 Fine Quality Flying Models ~_5~ V Catalog $150 98 RUBBER POWER KITS plus Gliders CIL RIC Accessories Books 444e 44 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 166 Model Aviation PK PRODUCTS Specializing Quadra/Zenoah Sales Service PO Box 6226 Hayward CA 94544 Tel 415 5B1-4277 Eves H & K Superstarters Q-35$2995 Q-50$2995 MAG II$3495 Super Hustler$3495 Zenoah$2995 Tartan Twin$3995 DEALER INQUIRIES IN V/TED ALL ORDERS ADD $150 POSTAGE & HANDLING CALIF RES ADD SALES TAX TV GLOW lire cdl PLUGS NEW IMPROVED High Performance Glow Element Blow Proof Seal Six Types 3 Heat Ranges Longer Life Only $129 Swanson Associates PO Box 151E~ Since 7948 Wayne NJ 07470 Perma-Grit Litetime * Carbide Sanding Tools Tungsten Carbide grit est material next diamond Tungsten carsido grit brazed steel 9 long tool use no balsa hardwooOs bborglass beaded foamo epooc fliers pleoiglasAcerago Meeters Use excellent tools modeler can use Don Dowe Professional Engineer Made USAr-tOO i1a2r C,riIri,$051 i-br Fin$655 Ask hour Dealer send cheekF-IllFiat C,$051 o MO No COOsI soC-Ill Fdiur Ca,eIFi,$055 otot irtOtS DG Productso-2eaoorco,JF,5625 209 carriands Driveella rCun/Fitnns Dayton OH 45429 r-n,ed-CoelFrnesass 15131 294-1192 residents oddt%tao NOW THERES QUICK AND EASY WAY OF CLEANING YOUR MODEL CRAFTS Super-K Model Cleaner Removes freI Residue dirt contact CUTS CLEANING TIME IN HALF Just spray model solvent wipe soft cloth paper towel SIMPLE AS THAT Leaves craft showcase clean eWoVt harm PaInts Covedngs Dues Cleor fast S Ulminatee Yek cleaning model Strong Professional Quality formula Great Model Craft Bcots Planes Helicopters Cleans Gently Protects delicate model DEALERS WANTED DOMESTIC & OVERSEAS WE EXPORT Hurryl Have product shelves time Christmas guaranteed top seller Sugg retail $550 per gallon Contact us price structures ordering information Also ask about other Super-K products Model Industry Ate Manufacturers & Major Brands DIstributors Model Engines Kits Radios & Accessories super K S orana Kings Radio Control Hobbies International 3960 West 16th Ave Hialeah Florida 33012 Phone 305 557-2024 joint glued epoxy system provides very strong wing center section gradually stepped re duction strength weight outward along span Note no two spruce spar doublers end same rib station main stub spar webs stop different ribs strength neededmostly very middle less less along span Incidentally wing also has /s sq balsa turbulators serve no primary strength function 536 sq MonoKoted wing weighs 6/3 oz supports Spectra Soars 39-oz total weight plane currently holds KRC loops-per-minute record 22 think doesnt put screws wing structure give try see wing holds up Obviously specific illustratioin just given cannot aply exactly wing Larger wings need proportionately larger wood sizes conversely smaller wings can get away lesser wood bulk basic idea what important use material resources wisely appropriately task hand Economize material weights sake dont trade off strength counts Such discretion results building time earns large re turns longer andlor better flights time spent rebuilding glider wing probably has greatest need span-wise strength because its generally higher aspect ratio re sulting large structural load other extreme aerobatic Electrics generally have stubbiest lowest aspect ratio wings Sometimes wings have partial planking over upper surface almost never have spars covering level ie have smoother surfaces illus trations show some very workable structural options As might have guessed other wingsthose Old Timers OT Scale broad category called Sportcan readily employ blends suggested con struction techniques course OT Scale dictates may preclude exercise possible options Whatever construction approach selected lose sight need keep weight low strength high could argue point mod els Electric otherwise basic differ ence Electric such con siderations essential best performance Study accompanying structural sketches refer back Part 7 noting wing weights advised examples presented have least loopedsome vigorously opin ion wing cant looped yield ing its worth having Tail assemblies can very simple Most sheet balsa structures Choose fairly light warp-free wood achieve strength durability using harder cap strip material generally cap leading trailing edges ends hard balsa strips same thickness sheet material width two times thickness have found 3A2 sheet quite ade quate planes up about 3 3 lb I/f sheet works fine about 6 lb latter far Ive gone far have used number built-up tail struc tures size-for-size can made lighter solid sheet types still have adequate durability range Electrics up about 6 lb choose firm LE TE stock /4 thickness width two four times thick ness Ribs cross braces may square stock Ailerons elevators rudders have thing common need hinges Fellow flier John Hickey introduced hing ing technique several years ago have adopted 100% have several other Electric fliers Scotch brand Plastic Tape transparent tape available sev eral colors two widths makes excel lent hinges used illustrated always use -in-wide clear type pn 2t0062 because permits color MonoKote show through stuff costs about buck 125 real bargain application can purchased staionery variety hard ware stores have hundreds flights same hinges no evidence fa tigue have flown temperature extremes low 250 higher 1000F no problem tape very light strong offers added advantage closing hinge gap used shown have no idea holds up presence fuel has never failed its absence far know Fuselage construction can range very simple sheet box modified sheet box all-sheet all-stick all-sheet box simplest quickest build fuselages either modified variety all-stick Basically modified sheet box struc ture consists simple sheet sides partly open structure top bottom another example quarter ouncing Electric approach suitable applications sketches should tell story Additionally may want refer earlier parts series text photos have shown proven motor battery radio mounting techniques mounting areas require strongest struc tural materials places ma terial selection important keeping weight under control adequate strength Regarding material selection have plenty flying success /if sheet balsa sides models weighing up about 3 lb Several years ago 6-lb twin t5-powered Astrobat /8 sheet sides partial inside doublers /& ply wing skin material now consider structure have overkill course some judg ment regarding balsa grain density always important / ply wing skin very handy easy-to-use material can add tremendous strength along minimal weight di168 Model Aviation IN STOCK FOR IMMEDIATE SHIPMENT New 30 ClD QUADRA $19995 New 22 CID QUADRA $10950 ReQ 22 QUADRA $9995 Brinighelia Fiywheel$11995 Reg 22 QUADRA POWER ASSEMBLY ONLY$6450 QUADRA REPAIR 000 plan parts Jim Menner ERCOUPEPLANS $2395 KIT $23995 Jim Manner TOMAHAWKPLANS $2395 KIT $25995 Jim Menner9-BALLTRAINER PLANS $1895 KIT $9995 BALSA BASSWOOD sicenl 35% OFF Concept FLEET PLANS $2995 KIT $15995 COWL $1995 FLOATS 361/5 scale cores $1750 conspiete kit $3950 FLOATS 49 scalecores $2195 conspiete kit $4795 1$ WWl WHEELS $2595 P&W CYIS FLEETI6I$2596 PLANS SUPER STEARMAN Godfrey $2895 STARDUSTER TOO IBrinighellal 54 J3 CUB Neiite $2995 VOLKSPLANE Chicken Charliel$2395 COCKPIT KITS Tomahawk F4U-1 Spitfire$2295 Ercoape $2095 Stearrnan $2295 Citabria $2495 J3 Cab $2195 ME-lOS $2295 Pleat $2198 US Doadra FUEL TANKS16 oc $695 32 oc $795 FIBERGLASSARROWSHAFTS5/1603210fl9 6/81000 24-Hour. Add $250 postage Send Bank check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706 mensional growth places model Large surface areas such fuselage side doublers can adhered contact cement smaller areas can handled conventional modeling adhesives use ply wing skin line holes balsa nose blocks serve structural motor mounts shown earlier installment Another very useful material /8 Lite Ply material poplar think stronger heavier balsa strong heavy birch ply has useful applications A-in thickness properties three-ply laminate ad vantageous often use formers structural motor mounts pictured Part 2 Whichever technique materials choose think about what youre doing pick up piece wood Spend few bucks 16-oz postage diet scale use youre building can quite educational surprising source free structural strength covering material Specif ically proper application MonoKote other plastic covering sheet balsa struc tures will add significantly finished strength durability probably case other covering materials well dont have firsthand experience call free benefit because certainly some kind finish its associ ated weight will always used thats needed claim benefit proper ap plication Loose bubbled MonoKote sheet surfaces does much good smooth evenly-adhered covering does Thus suggest pay little extra atten tion next cover sheet surface such fuselage side tail surface Virtually building now done CyA adhesives includes sticks Playboy OT few places still use epoxy favorite Hobbypoxy Formula 1 epoxy neither real fast nor real slow does excel lent job dihedral joints few other select applications dihedral joints always butt joints first doubled later mean wing centers panel completed planking etc dihedral mating sur faces sandedflat good fit LE LB spar spar planking planking nifty end-grain gets thin finger smear Formula 1 soaks 15-20 mm new batch mixed applied following surfaces held together few hours Finally dihedral braces installed Remember Part 1 said Elec tric can make better builder care ful choice materials careful fitting joints CyA can its job epoxy right places no globs please careful covering adhesion true quarter ounc ing techniques no penalties strength department minimal premium building time ever returned glow-engine flying Id still build way Next month well have continuation Planes Flying taking look some successful Electrics flown recent KRC Electric Fly events Well also develop list motors props batteries sociated operating power levels latter information combined previous sec tions rules thumb herein should allow plan own successful Elec trics time want express sincere thank letters expressing appreciation encouragementand requests information letters have resulted some new thinking part series possibly some followup articles Any questions comments etc section previous ones may directed SASE author Bob Kopski 25 West End Dr Lansdale PA 19446 Kingfisher/Perry Continued page 87 dig wing surface Vacuum wing before applying low-temperature covering film such Solar Film Flying conventional low-speed flight particularly young inexperienced pi lot prefer use forward balance point limit up-elevator model will stall Set engine idle power just sufficient maintain level flight under dead-calm conditions Normal flying conditions will require slight continued page 172 Open up new wodd modeling excitement days modelers wont settle puttering around sky hours end want loops rolls spins want quality balsa kits - parts fit right out box want Great Planes youre RIC modeler thats interested perform ance should know about extensive line over 35 kits new catalog tells whole story - sport/trainers competition pattern giant scale sport scale designed Great Plane Clip out coupon return us today enter world Great Planes ~UUVACflCOiAN P0 80372URBANANOS6SA36 069 want put some excitement modeling Send FREE 1984 Great Planes catalog kits accessoriesI NAMEI ADDRESS CITY STATE ZIPI Return Great Planes Model Mtg PO Box 7210 Urbana Illinois 61801I

The author provides six rules thumb will help achieve what calls Electric Elation boot theres lots information con structing models have lots strength needed much strength weight its needed techniques helpful kinds modeling Part 8 about Bob Kopski THIS IS CONTINUATION topic begun last month what flies previous issue described detail makeup per formance four Electrics specific designs covered real message Part 7 nothing magical about particular examples planes similar makeup should fly com parably Now going cover some general ized rules thumb electric power some construction suggestions purpose further tie together earlier information help assure first-time continuing Electric successwhat call Electric Ela tion Rule thumb number have stated repeatedly extremely important con sideration determining flying quality Electric weight promised show quantitatively Motor Power Input Cruise s oz x oz/sq planes Another convenient equivalent way express Watts ht lbs x Wing Loading oz/sq ft rule thumb empiricism fitted expression carefully con trolled flight experiments Several comments order First note units make normal sense Watts same ounces squared divided sq dont let bother Also power input power volts x amps motor observed static condition something can measured bench Further expression applies nominal airplane reasonable design outfitted appropriate motor battery propjust kind plane people would like fly Lets take example Remember Sport Scale J-3 discussed last month rewarding flight maneuvers model simple realistic cruising level flight power required P 68 X 681700 about 60 watts Does really work Yep established marking throttle control position transmitter plane cruis ing level flight measured elec trical power input throttle setting bench did several times Another technique used established above equation choose plane good climb rate proceed add weight CG until sustained level flight cruise same power achieved did several times several different planes Results two methods always agreed closely Ponder bit note indeed very useful information effect allows know ahead time plane going fly relationship can also used determine what kind bat tery needed fly such-and-such plane long done using infor mation earlier parts series some coming up shortly wants just cruise around Im sure Thats point way because power beyond cruise power level will cause plane climb cruise condition used convenient condition measurement because cruise something can achieved observed repeatedly climb rate much tougher ascertain course cruise used discussion condition plane just maintaining level flight observed low enough altitude assure indeed level flight Also level flight does mean constant level screamby aerobatics Now weve set stage lets get real point power required battery cruise proportional models weight squared planes Youd better back up read again means example 10% crease weight requires about 21% crease power same nominal flight April 1984 77 Household scales very helpful getting know Electric will fly left has 16-oz range making useful during model construction keep tally quarter ounces scale four S-22 servos pointer 2% oz About half total weight finished Electric shown resting larger scale Astro 40 Cobalt 14 12 Ah cells come 2 lb 10 oz wiring installation will add another 1 2 oz making total power system about 44 oz finished plane should weigh about 5% lb performance Example 30-oz model needs 3 oz added to suffer re duced motor run time over one-fifth some powered flight performance Three 16 oz servos instead three O6-oz ones will should now clear quantitativelythat weight very impor tant Weight sensitive parameter cause multiplied itself determine well long Electric will fly Friends watch out quarter ounces Rule thumb number two motor input power battery drain required ROG takeoff about 30 50 watts per pound nominal airplane lot variables involved thats theres such spread possible range power values Again guideline empiricism describes results Ive over several years several planes general planes lighter wing load ings larger wheels good runways glider wing structure similar text description Main stub spars hard balsa doubled sides square spruce stock Webbing spruce doublers end staggered lengths providing small steps strength weight reduction along span vertical balsa filler front TE ends before gets tip TE rear cap added after otherwise-completed wing panel removed workbench Block-sand sheet balsa joint hold glued cap position strips masking tape Afterwards remove tape round edges cap sketch planking dihedral omitted clarity need less power get off Models small wheels plush spring grass need much power true no matter what powers model electric motor effect start ground roll static thrust motor/propeller must sufficient get wheels moving delivered power must sufficient accelerate plane speed adequate lift-off course desirable fly plane off ground horse air Lets look example J-3 again gross weight 4 lb plane has thick flat bottom airfoil light wing loading large 3-in balloon wheels normally flies very slowly easily gets off field conditions predicted power requirement takeoff 4 pounds x 30 watts/lb about 125 watts Astro 15 belt-drive speed reducer Top Flite 12-8 wood prop has power input about 160 watts full throttle takeoff easy course some headwind always helps planewhether plane Elec tric Gasbut 1-3 doesnt need Another example support rule thumb older plane Superkick name long complicated story dont ask Superkick design derived popular Falcon 56 has stretched wing 68 otherwise con forms Falcon force setup course structure bears no resemblance kit aspect customized Elec tnc Superkick flown controls motor elevator rudder Motor con trol servo-driven OFF-LO-HI Motive power older version Astro 25 16 12 Ah cells 9-6 Top Flite wood prop All-up weight 81 oz wing loading about 17 oz/sq ft plane has steerable nose wheel handles very well ground almost always takes off although sometimes little body English needed Lets test rule thumb Superkick uses NACA 2412 Falcon semisymmetrical airfoil has relatively heavy wing loading relatively small wheels 21/4 in three places model neither taxies nor lifts off easily 1-3 its reasonable expect proportionately higher power needed get off Using numbers 5 lb 50 watts/lb get predicted requirement about 250 watts Nominal operating conditions electric motor system described 250 280 watts inputjust right course rule thumb can ex tended fit other examples beyond two given sense somewhat flexible guideline however pect ground handling takeoff per formance Despite meeting suggested guideline conditions some planes power sys tems may just too small typical outdoor flying conditions As best can tell about smallest power system can assure reliable ground handling takeoff around 150 watts Yes excep 78 Model Aviation tail structure made 3/32 sheet balsa per text picture MonoKote covering has dusted talc reduce glare highlight tape edges Continuous tape strips used rudder elevator hinges look closely bottom rud der Center end elevator may see edges iron-on cloth reinforcements toughens balsa surface vicinity control horn attachments Scotch brand Plastic Tape has proven practical hinging material Electrics thousands flights o 1-4 SPRUCE DOUBLERS END o 1-2 STUB SPAR PAIR -EXCEPT BOTTOM PIECE EXTENDS OUTWARD D 1-2 WEBBING ENDS tions Playboy about 90 100 watts onemost time Anyway lot depends specific field conditions wheels etc Please take offerings herein what really composite experience-backed guidelines should least put ball park now mumbling some thing about dickens youre supposed know much power goes motor prop battery After two rules thumb dont mean much youre missing power information Hang tight gang know well survey soon Rule thumb number three guide line requires electric power system components make up about half total weight RC Electric As other parameters also has some tol erance Reasonable limits range 40% 60% Several examples described Parts 5 7 Rule thumb number four wing largest area component models Ive singled out its very own guide line wing Electric RC model should weigh about 2 oz per sq ft Reason able limits 18 22 oz per sq ft lower limit typical smaller gliders upper larger limit applicable aero batics suggested weights complete wing structures including ser vos landing gear components working guideline helpful know Super MonoKote weighs about V4 oz per sq ft remember covered area twice wing area No Im familiar other covering weights Implicit guideline wing weight simultaneous need adequate strength have learned hard way use typical modeling materials make wings other components both light strong some information difficult put words well give try bit later meantime assured lightness does necessarily mean weak ness Rule thumb number five time Think terms quarter ounces four make up ounce four make up quarter pounder may bit overbearing now very important have witnessed disappointment too-heavy plane no need happen Think light Ive acknowledged Electrics heavier other types models also insist Electrics quite flyable ever must part help assure success Simply put must make up some weight electric system components using well-considered con struction techniques quite pos sible generally some self-discipline breaking bad habits may re quired Rule thumb number six comes tough Forget kits Spar details sketch similar Euphoria Two acrobatic model weighs 58 oz has wing 50-in span 9Yz-in chord Among its repertoire inside outside loops very fast roll very strong lightweight structure has gradually-stepped strength weight reduction along span Spars boxed inside semi-symmetrical ribs bump-free covering surface Center planking dihedral details omitted clarity spar structure 3/16 light balsa core capped 3/16 sq spruce near root hard 3/16 sq balsa outward Note staggered transition points spruce-to-balsa caps Spar sides reinforced 1/64 ply center ending outward-staggered points Ribs 1/16 balsafirm root lighter outward aileron actually hollow capped balsa triangular structure resulting cutting along length hollow TE assembly Plastic tape hinging very easy install Position covered surfaces 1/32 1/16 apart allow bind-free operation cover side continuous strip tape half width surface Before applying tape make sure covering material firmly adhered wood beneath ittoo late apply heat after tape place Add few tape doublers other side sticky side inward touches sticky side first tape gap area snap hinged surface can folded back itself along first tape hinge line otherwise fold tape strip over thin metal strip sticky side out insert author uses tape doublers near root tip movable surface two along length depending upon size plane Nobody ever likes hear fact everyone has developed bad life however kits designed habits such kits virtual lumberfor glow engine power Over years glow busses worse foam farms see engines have grown tremendously power usually doesnt matter too much output given displacement along Continued page 80 Modified box fuselage assembly has open structure top bottom aft wing loca tion typical structure has 1/16 sheet sides 1/8 sq strip vertical stiffenersstopping top bottom sheet After sides joined rear 1/16 x / cross strips added verticals top bottom Lengths 1/16 x added along four edges cap side sheeting verticals cross braces partially Finally 1/16 x /4 strips laid flat cap vertical cross strips multi-piece structure very light strong easy CyA glue Dont let complicated description scare trying April 1984 79 fA- P [/32 1/16 PLASTIC TAPE FULL LGTH STICKY SIDE USE THIN METAL STRIP TOTRIM OF F AFT PUSH FOLD UP TO TOP TAPEINSTALLATION 2-4 PLACES -r cUijriccIic] 322 So Gallatin RdMadison TN 37115 615 868-6811V Mon thru Sat 900am 500pm FUTABA RADIO SALE~k Because care REPAIR SERVICE FOR AIIradiosystemsar0prBchBCk0df& S proper operation prior shipment RADIO SYSTEMS HOBBY LOBBYFP-713K 72FM5-128 Iist$38995$24 FUTABA ROYAL E K LOG CT RO LFP-70K 72AM5-281ist5359SS. $22500 FUTABA T EP-SOK 72FM 5-128 IistS3l99$. $20 00 ACCESSORIES FOR TP-50K 72AM S-28IistS2899$ . 50 HOBBY SHACKFP-4LV$13 S-28servosIist$19995. $11500MOST RADIOS ROYAL LINEAdd $295 Prepaid Mastercard Visa COD $495 Tenn residents add 575% tanVISA WILLIATMSACCESSORIS BROTHERS ________________ 4 PILOTS STANDARD TSMANinfu WHEEL NG TARY VINTAGE TH BALLOON EN AGE 4 ENGINES PRATT & WHITNEY HT HONE PARTS HITNEY HONE PRAtT WRIGHT E GUNS LEWISVICKERS DAU BELILIM SEND $1 FOR FULLY ILLUSTRATED CATALOG4LJAa DEPT MA 1 u IAWNEE ST SAN MARCOS CALIFORNIA 92069 glowan extra pound two often goes un noticed Its easy change nitro level tank size engine size Elec tric So youll need forget kits As might expect excep tions Some kits especially gliders adapt fairly easily electric power majority kits readily convert Electric lots kit designs look like excellent candidates quiet mo tivation Thus have some favorite glow-engine kit plans wonder Elec tric version would possible just pay tention series have desire convey enough insight information reasonably-skilled modeler can deter beforehand what needed assure Electric success other extreme some kits intended Electric have per sonally seen several including Astro Porterfield Astro Sport shoulder-wing ver sion Leisure Playboy Larry Jolly Electricus Youd have work hard go wrong few other kits Electric dont have upfront familiarity cant com ment Paradoxically relatively few kits ever-increasing number fine Electric model designs appearing modeling magazines Ive personally seen several perform fly very well course must scratchbuilding nature Sometimes good magazine design becomes kit Porterfield example understand Wasp its way being kitted As what I nearly always design build scratch Lately however Ive taken interest some kits modifications might needed con vert good Electric models Some Construction Guidelines Now weve seen hard data vital statistics rules thumb planes fly well lets look beneath covering see theyre put together Lets start wing tend divide three groups gliders aero batic flying other kinds flying Electric-powered model glider wings can have similarities differences Sailplanes Both types have relatively high aspect ratios Electric glider must support mass power installation Sailplane must tolerate tow air foil can favorite either case Covering can same Whats really different Weight Some weight Sail plane less wont really matter times planes ballasted way Electric chal lenging difference Lets get some details tend avoid discourage plugtogether wings obviously makes large Electric gliders bit problem What comes down chosen design wont fit family buggy singlepiece wing must made piece will have weight Continued page 82 80 Model Aviation fL15 FULL LINE METAL SPECIALISTS penalty several ounces can mod erated bit wont have tow loads contend hardware associated holding wing parts together can lighter size weight Unfortunately personally dont have hands-on exam ples area can offer observation generalization Ive seen fair share wings fold failure almost always near wing center exactly what expect bending moment greatest obviously thats place invest some weight strength follows made near-center region super strong next failure location would further out just past super-strong part failure would less apt happen because bending moment less wing center could simply make next region part past super-strong center lust very strong next possibility fail ure would occur further out wing panel discussion has treated discrete regions wing should clear effects really gradual nature really should thought steps effect what really needed wing structure having relatively smooth variation strength weight super strong very middle very little strength tip What Ive said hardly new stuffs known seems forever prac ticality matter its much easier build wing relatively uniform strength along span gradually di minishing strength simpler wing heavier thats what about build glider wings some others well step-wise varying strength technique gradually reduce wing strength weight root tip series small steps simple compromise between virtually no variation smooth tapering variation latter can ex tremely tedious time-consuming build step-wise approach easy understand though cumbersome describe words wings usually all-balsa root tip supplemented varying-length spruce additions balsa leading edge eable soft trail ing edge usually hollow-triangle type made sheet balsa top bottom filler strips between ribs front rear trailing edge capped simple balsa strip except near center spruce cap used tolerates wing rubberbands much better So far theres nothing unusual big difference comes spars make hard balsa rectangular cross section As now common practice spruce two laid flat top bottom ribs near point maximum thickness Vertical-grain balsa webs installed tween top bottom spars along entire span legitimate Continued page 166 82 Model Aviation SUPERwings DIVISION OF HI JOHNSON MODEL PRODUCTS 11015 GLENOAKS BLVD PACOIMA CA 91331 SAILPLANE COMPONENTS CREATE YOUR OWN SUPER GLIDER WING FOAM CORES Floater Thermal & Slope FUSELAGES LUSTROLEEN 2 Meter Standard Open & Scale STAB FOAM CORES Rudder & Fin Cores COVERING MATERIALS White skin & Lustroleen WING RODS Wing Tongue Kits FOR HI JOHNSONS PORTFOLIO PRICE SHEET & ORDER FORM about sailplane construction & design using foam & plastic SEND $250 CHECK OR MO CA RES ADD SALES TAX enough clearance properly strike pro peller am enclosing two photographs showing different methods starting method flip engine forward having compression set pro peller blade two oclock position slapping propeller extremely hard engine starts flip Another method flip engine backwards strik ing propeller very close hub propeller must set horizontal parallel ground method produce satis factory results Certainly pilot must job bringing plane substantial speed getting out pits back air shortest possible interval time certainly cannot emphasize impor tance thorough complete practicing improve overall race times Know racing-circle markings Finally find competitors mark off standard circle AMA specifications use practice cases flying school parking lots etc impera tive use either chalk spray paint owner will allow mark off proper center circle landing circle pitting area Practicing under standard circle conditions improves relationship between pilot pitman since landings takeoffs done same circle atmosphere will used under competitive situa tions NEW Tartan Twin Muffler Set Allows adjustment carb running $3995 400 RPM increase over stock As always comments solicited appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Electrics/Kopski Continued aoe 82 weight saving quarter ouncing because wings dont fold tips Two additional balsa spars used top bottom about halfway between main spars trailing edge latter spars can partial span so-called stub spars Like main spar pair stub spars also webbed part length Usually bottom spar stub pair continued full span supporting ribs use stub spar seems like obvious extension now-common main I-beam some reason commonly used departure established prac tice light easy adds great deal strength high aspect ratio wings stub spars may bit unusual big difference comes now four spars get spruce doublers staggered length beginning root extending outward along main panels stopping dif ferent rib stations minimizes amount comparatively heavy material putting its strength will gooddistributed step-wise center outward Most Sailplane wings sim 3-FUNCTION ACCUETACH ITM Lb LCD Tachometer w/dual scale capability lOX bOX @ Digital Voltmeter load /5 && checking/cycling TX/RX battery combos ACCU-TACHI torquick charging operation w~9 7 9aitt Send check Noror money order Ca t add 600 tax PO Box 70956 AVIONRSS Sunnyvale CA INC94086 ply use spruce way sparstrue indiscretion true overkill inverted quarter ouncing Lets describe example Its Spec tra Soar wing 8-in chord 67-in span rectangular planform poly dihedral main panels 20 long tip panels 13 ribs spaced 21/2 relatively light Ak balsa four hard balsa spars Vt X /4 main pair goes full span although balsa used tip panel spars also rela tively light stub spar structure 121/2 long five ribs main spar webbing covers four ribs stub spar webbing three spruce spar doublers square glued alongside balsa spars bottom main spar doubler five ribs long top four ribs long bottom stub spar doubler three ribs long top two ribs long particular example spruce doubler spars located TE side balsa spars full-depth Vik ply wood dihedral barces 2-in length glued spruce pieces form super strong center dihedral joint short dihedral brace also used behind balsa leading edge wing center planked over rib bay panel iA6 balsa top bottom done before dihedral joint made allowing mating surfaces snded flat tight fit maximum spar planking end-grain contact produce truly strong dihedral Continued page 168 Fine Quality Flying Models ~_5~ V Catalog $150 98 RUBBER POWER KITS plus Gliders CIL RIC Accessories Books 444e 44 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 166 Model Aviation PK PRODUCTS Specializing Quadra/Zenoah Sales Service PO Box 6226 Hayward CA 94544 Tel 415 5B1-4277 Eves H & K Superstarters Q-35$2995 Q-50$2995 MAG II$3495 Super Hustler$3495 Zenoah$2995 Tartan Twin$3995 DEALER INQUIRIES IN V/TED ALL ORDERS ADD $150 POSTAGE & HANDLING CALIF RES ADD SALES TAX TV GLOW lire cdl PLUGS NEW IMPROVED High Performance Glow Element Blow Proof Seal Six Types 3 Heat Ranges Longer Life Only $129 Swanson Associates PO Box 151E~ Since 7948 Wayne NJ 07470 Perma-Grit Litetime * Carbide Sanding Tools Tungsten Carbide grit est material next diamond Tungsten carsido grit brazed steel 9 long tool use no balsa hardwooOs bborglass beaded foamo epooc fliers pleoiglasAcerago Meeters Use excellent tools modeler can use Don Dowe Professional Engineer Made USAr-tOO i1a2r C,riIri,$051 i-br Fin$655 Ask hour Dealer send cheekF-IllFiat C,$051 o MO No COOsI soC-Ill Fdiur Ca,eIFi,$055 otot irtOtS DG Productso-2eaoorco,JF,5625 209 carriands Driveella rCun/Fitnns Dayton OH 45429 r-n,ed-CoelFrnesass 15131 294-1192 residents oddt%tao NOW THERES QUICK AND EASY WAY OF CLEANING YOUR MODEL CRAFTS Super-K Model Cleaner Removes freI Residue dirt contact CUTS CLEANING TIME IN HALF Just spray model solvent wipe soft cloth paper towel SIMPLE AS THAT Leaves craft showcase clean eWoVt harm PaInts Covedngs Dues Cleor fast S Ulminatee Yek cleaning model Strong Professional Quality formula Great Model Craft Bcots Planes Helicopters Cleans Gently Protects delicate model DEALERS WANTED DOMESTIC & OVERSEAS WE EXPORT Hurryl Have product shelves time Christmas guaranteed top seller Sugg retail $550 per gallon Contact us price structures ordering information Also ask about other Super-K products Model Industry Ate Manufacturers & Major Brands DIstributors Model Engines Kits Radios & Accessories super K S orana Kings Radio Control Hobbies International 3960 West 16th Ave Hialeah Florida 33012 Phone 305 557-2024 joint glued epoxy system provides very strong wing center section gradually stepped re duction strength weight outward along span Note no two spruce spar doublers end same rib station main stub spar webs stop different ribs strength neededmostly very middle less less along span Incidentally wing also has /s sq balsa turbulators serve no primary strength function 536 sq MonoKoted wing weighs 6/3 oz supports Spectra Soars 39-oz total weight plane currently holds KRC loops-per-minute record 22 think doesnt put screws wing structure give try see wing holds up Obviously specific illustratioin just given cannot aply exactly wing Larger wings need proportionately larger wood sizes conversely smaller wings can get away lesser wood bulk basic idea what important use material resources wisely appropriately task hand Economize material weights sake dont trade off strength counts Such discretion results building time earns large re turns longer andlor better flights time spent rebuilding glider wing probably has greatest need span-wise strength because its generally higher aspect ratio re sulting large structural load other extreme aerobatic Electrics generally have stubbiest lowest aspect ratio wings Sometimes wings have partial planking over upper surface almost never have spars covering level ie have smoother surfaces illus trations show some very workable structural options As might have guessed other wingsthose Old Timers OT Scale broad category called Sportcan readily employ blends suggested con struction techniques course OT Scale dictates may preclude exercise possible options Whatever construction approach selected lose sight need keep weight low strength high could argue point mod els Electric otherwise basic differ ence Electric such con siderations essential best performance Study accompanying structural sketches refer back Part 7 noting wing weights advised examples presented have least loopedsome vigorously opin ion wing cant looped yield ing its worth having Tail assemblies can very simple Most sheet balsa structures Choose fairly light warp-free wood achieve strength durability using harder cap strip material generally cap leading trailing edges ends hard balsa strips same thickness sheet material width two times thickness have found 3A2 sheet quite ade quate planes up about 3 3 lb I/f sheet works fine about 6 lb latter far Ive gone far have used number built-up tail struc tures size-for-size can made lighter solid sheet types still have adequate durability range Electrics up about 6 lb choose firm LE TE stock /4 thickness width two four times thick ness Ribs cross braces may square stock Ailerons elevators rudders have thing common need hinges Fellow flier John Hickey introduced hing ing technique several years ago have adopted 100% have several other Electric fliers Scotch brand Plastic Tape transparent tape available sev eral colors two widths makes excel lent hinges used illustrated always use -in-wide clear type pn 2t0062 because permits color MonoKote show through stuff costs about buck 125 real bargain application can purchased staionery variety hard ware stores have hundreds flights same hinges no evidence fa tigue have flown temperature extremes low 250 higher 1000F no problem tape very light strong offers added advantage closing hinge gap used shown have no idea holds up presence fuel has never failed its absence far know Fuselage construction can range very simple sheet box modified sheet box all-sheet all-stick all-sheet box simplest quickest build fuselages either modified variety all-stick Basically modified sheet box struc ture consists simple sheet sides partly open structure top bottom another example quarter ouncing Electric approach suitable applications sketches should tell story Additionally may want refer earlier parts series text photos have shown proven motor battery radio mounting techniques mounting areas require strongest struc tural materials places ma terial selection important keeping weight under control adequate strength Regarding material selection have plenty flying success /if sheet balsa sides models weighing up about 3 lb Several years ago 6-lb twin t5-powered Astrobat /8 sheet sides partial inside doublers /& ply wing skin material now consider structure have overkill course some judg ment regarding balsa grain density always important / ply wing skin very handy easy-to-use material can add tremendous strength along minimal weight di168 Model Aviation IN STOCK FOR IMMEDIATE SHIPMENT New 30 ClD QUADRA $19995 New 22 CID QUADRA $10950 ReQ 22 QUADRA $9995 Brinighelia Fiywheel$11995 Reg 22 QUADRA POWER ASSEMBLY ONLY$6450 QUADRA REPAIR 000 plan parts Jim Menner ERCOUPEPLANS $2395 KIT $23995 Jim Manner TOMAHAWKPLANS $2395 KIT $25995 Jim Menner9-BALLTRAINER PLANS $1895 KIT $9995 BALSA BASSWOOD sicenl 35% OFF Concept FLEET PLANS $2995 KIT $15995 COWL $1995 FLOATS 361/5 scale cores $1750 conspiete kit $3950 FLOATS 49 scalecores $2195 conspiete kit $4795 1$ WWl WHEELS $2595 P&W CYIS FLEETI6I$2596 PLANS SUPER STEARMAN Godfrey $2895 STARDUSTER TOO IBrinighellal 54 J3 CUB Neiite $2995 VOLKSPLANE Chicken Charliel$2395 COCKPIT KITS Tomahawk F4U-1 Spitfire$2295 Ercoape $2095 Stearrnan $2295 Citabria $2495 J3 Cab $2195 ME-lOS $2295 Pleat $2198 US Doadra FUEL TANKS16 oc $695 32 oc $795 FIBERGLASSARROWSHAFTS5/1603210fl9 6/81000 24-Hour. Add $250 postage Send Bank check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706 mensional growth places model Large surface areas such fuselage side doublers can adhered contact cement smaller areas can handled conventional modeling adhesives use ply wing skin line holes balsa nose blocks serve structural motor mounts shown earlier installment Another very useful material /8 Lite Ply material poplar think stronger heavier balsa strong heavy birch ply has useful applications A-in thickness properties three-ply laminate ad vantageous often use formers structural motor mounts pictured Part 2 Whichever technique materials choose think about what youre doing pick up piece wood Spend few bucks 16-oz postage diet scale use youre building can quite educational surprising source free structural strength covering material Specif ically proper application MonoKote other plastic covering sheet balsa struc tures will add significantly finished strength durability probably case other covering materials well dont have firsthand experience call free benefit because certainly some kind finish its associ ated weight will always used thats needed claim benefit proper ap plication Loose bubbled MonoKote sheet surfaces does much good smooth evenly-adhered covering does Thus suggest pay little extra atten tion next cover sheet surface such fuselage side tail surface Virtually building now done CyA adhesives includes sticks Playboy OT few places still use epoxy favorite Hobbypoxy Formula 1 epoxy neither real fast nor real slow does excel lent job dihedral joints few other select applications dihedral joints always butt joints first doubled later mean wing centers panel completed planking etc dihedral mating sur faces sandedflat good fit LE LB spar spar planking planking nifty end-grain gets thin finger smear Formula 1 soaks 15-20 mm new batch mixed applied following surfaces held together few hours Finally dihedral braces installed Remember Part 1 said Elec tric can make better builder care ful choice materials careful fitting joints CyA can its job epoxy right places no globs please careful covering adhesion true quarter ounc ing techniques no penalties strength department minimal premium building time ever returned glow-engine flying Id still build way Next month well have continuation Planes Flying taking look some successful Electrics flown recent KRC Electric Fly events Well also develop list motors props batteries sociated operating power levels latter information combined previous sec tions rules thumb herein should allow plan own successful Elec trics time want express sincere thank letters expressing appreciation encouragementand requests information letters have resulted some new thinking part series possibly some followup articles Any questions comments etc section previous ones may directed SASE author Bob Kopski 25 West End Dr Lansdale PA 19446 Kingfisher/Perry Continued page 87 dig wing surface Vacuum wing before applying low-temperature covering film such Solar Film Flying conventional low-speed flight particularly young inexperienced pi lot prefer use forward balance point limit up-elevator model will stall Set engine idle power just sufficient maintain level flight under dead-calm conditions Normal flying conditions will require slight continued page 172 Open up new wodd modeling excitement days modelers wont settle puttering around sky hours end want loops rolls spins want quality balsa kits - parts fit right out box want Great Planes youre RIC modeler thats interested perform ance should know about extensive line over 35 kits new catalog tells whole story - sport/trainers competition pattern giant scale sport scale designed Great Plane Clip out coupon return us today enter world Great Planes ~UUVACflCOiAN P0 80372URBANANOS6SA36 069 want put some excitement modeling Send FREE 1984 Great Planes catalog kits accessoriesI NAMEI ADDRESS CITY STATE ZIPI Return Great Planes Model Mtg PO Box 7210 Urbana Illinois 61801I

The author provides six rules thumb will help achieve what calls Electric Elation boot theres lots information con structing models have lots strength needed much strength weight its needed techniques helpful kinds modeling Part 8 about Bob Kopski THIS IS CONTINUATION topic begun last month what flies previous issue described detail makeup per formance four Electrics specific designs covered real message Part 7 nothing magical about particular examples planes similar makeup should fly com parably Now going cover some general ized rules thumb electric power some construction suggestions purpose further tie together earlier information help assure first-time continuing Electric successwhat call Electric Ela tion Rule thumb number have stated repeatedly extremely important con sideration determining flying quality Electric weight promised show quantitatively Motor Power Input Cruise s oz x oz/sq planes Another convenient equivalent way express Watts ht lbs x Wing Loading oz/sq ft rule thumb empiricism fitted expression carefully con trolled flight experiments Several comments order First note units make normal sense Watts same ounces squared divided sq dont let bother Also power input power volts x amps motor observed static condition something can measured bench Further expression applies nominal airplane reasonable design outfitted appropriate motor battery propjust kind plane people would like fly Lets take example Remember Sport Scale J-3 discussed last month rewarding flight maneuvers model simple realistic cruising level flight power required P 68 X 681700 about 60 watts Does really work Yep established marking throttle control position transmitter plane cruis ing level flight measured elec trical power input throttle setting bench did several times Another technique used established above equation choose plane good climb rate proceed add weight CG until sustained level flight cruise same power achieved did several times several different planes Results two methods always agreed closely Ponder bit note indeed very useful information effect allows know ahead time plane going fly relationship can also used determine what kind bat tery needed fly such-and-such plane long done using infor mation earlier parts series some coming up shortly wants just cruise around Im sure Thats point way because power beyond cruise power level will cause plane climb cruise condition used convenient condition measurement because cruise something can achieved observed repeatedly climb rate much tougher ascertain course cruise used discussion condition plane just maintaining level flight observed low enough altitude assure indeed level flight Also level flight does mean constant level screamby aerobatics Now weve set stage lets get real point power required battery cruise proportional models weight squared planes Youd better back up read again means example 10% crease weight requires about 21% crease power same nominal flight April 1984 77 Household scales very helpful getting know Electric will fly left has 16-oz range making useful during model construction keep tally quarter ounces scale four S-22 servos pointer 2% oz About half total weight finished Electric shown resting larger scale Astro 40 Cobalt 14 12 Ah cells come 2 lb 10 oz wiring installation will add another 1 2 oz making total power system about 44 oz finished plane should weigh about 5% lb performance Example 30-oz model needs 3 oz added to suffer re duced motor run time over one-fifth some powered flight performance Three 16 oz servos instead three O6-oz ones will should now clear quantitativelythat weight very impor tant Weight sensitive parameter cause multiplied itself determine well long Electric will fly Friends watch out quarter ounces Rule thumb number two motor input power battery drain required ROG takeoff about 30 50 watts per pound nominal airplane lot variables involved thats theres such spread possible range power values Again guideline empiricism describes results Ive over several years several planes general planes lighter wing load ings larger wheels good runways glider wing structure similar text description Main stub spars hard balsa doubled sides square spruce stock Webbing spruce doublers end staggered lengths providing small steps strength weight reduction along span vertical balsa filler front TE ends before gets tip TE rear cap added after otherwise-completed wing panel removed workbench Block-sand sheet balsa joint hold glued cap position strips masking tape Afterwards remove tape round edges cap sketch planking dihedral omitted clarity need less power get off Models small wheels plush spring grass need much power true no matter what powers model electric motor effect start ground roll static thrust motor/propeller must sufficient get wheels moving delivered power must sufficient accelerate plane speed adequate lift-off course desirable fly plane off ground horse air Lets look example J-3 again gross weight 4 lb plane has thick flat bottom airfoil light wing loading large 3-in balloon wheels normally flies very slowly easily gets off field conditions predicted power requirement takeoff 4 pounds x 30 watts/lb about 125 watts Astro 15 belt-drive speed reducer Top Flite 12-8 wood prop has power input about 160 watts full throttle takeoff easy course some headwind always helps planewhether plane Elec tric Gasbut 1-3 doesnt need Another example support rule thumb older plane Superkick name long complicated story dont ask Superkick design derived popular Falcon 56 has stretched wing 68 otherwise con forms Falcon force setup course structure bears no resemblance kit aspect customized Elec tnc Superkick flown controls motor elevator rudder Motor con trol servo-driven OFF-LO-HI Motive power older version Astro 25 16 12 Ah cells 9-6 Top Flite wood prop All-up weight 81 oz wing loading about 17 oz/sq ft plane has steerable nose wheel handles very well ground almost always takes off although sometimes little body English needed Lets test rule thumb Superkick uses NACA 2412 Falcon semisymmetrical airfoil has relatively heavy wing loading relatively small wheels 21/4 in three places model neither taxies nor lifts off easily 1-3 its reasonable expect proportionately higher power needed get off Using numbers 5 lb 50 watts/lb get predicted requirement about 250 watts Nominal operating conditions electric motor system described 250 280 watts inputjust right course rule thumb can ex tended fit other examples beyond two given sense somewhat flexible guideline however pect ground handling takeoff per formance Despite meeting suggested guideline conditions some planes power sys tems may just too small typical outdoor flying conditions As best can tell about smallest power system can assure reliable ground handling takeoff around 150 watts Yes excep 78 Model Aviation tail structure made 3/32 sheet balsa per text picture MonoKote covering has dusted talc reduce glare highlight tape edges Continuous tape strips used rudder elevator hinges look closely bottom rud der Center end elevator may see edges iron-on cloth reinforcements toughens balsa surface vicinity control horn attachments Scotch brand Plastic Tape has proven practical hinging material Electrics thousands flights o 1-4 SPRUCE DOUBLERS END o 1-2 STUB SPAR PAIR -EXCEPT BOTTOM PIECE EXTENDS OUTWARD D 1-2 WEBBING ENDS tions Playboy about 90 100 watts onemost time Anyway lot depends specific field conditions wheels etc Please take offerings herein what really composite experience-backed guidelines should least put ball park now mumbling some thing about dickens youre supposed know much power goes motor prop battery After two rules thumb dont mean much youre missing power information Hang tight gang know well survey soon Rule thumb number three guide line requires electric power system components make up about half total weight RC Electric As other parameters also has some tol erance Reasonable limits range 40% 60% Several examples described Parts 5 7 Rule thumb number four wing largest area component models Ive singled out its very own guide line wing Electric RC model should weigh about 2 oz per sq ft Reason able limits 18 22 oz per sq ft lower limit typical smaller gliders upper larger limit applicable aero batics suggested weights complete wing structures including ser vos landing gear components working guideline helpful know Super MonoKote weighs about V4 oz per sq ft remember covered area twice wing area No Im familiar other covering weights Implicit guideline wing weight simultaneous need adequate strength have learned hard way use typical modeling materials make wings other components both light strong some information difficult put words well give try bit later meantime assured lightness does necessarily mean weak ness Rule thumb number five time Think terms quarter ounces four make up ounce four make up quarter pounder may bit overbearing now very important have witnessed disappointment too-heavy plane no need happen Think light Ive acknowledged Electrics heavier other types models also insist Electrics quite flyable ever must part help assure success Simply put must make up some weight electric system components using well-considered con struction techniques quite pos sible generally some self-discipline breaking bad habits may re quired Rule thumb number six comes tough Forget kits Spar details sketch similar Euphoria Two acrobatic model weighs 58 oz has wing 50-in span 9Yz-in chord Among its repertoire inside outside loops very fast roll very strong lightweight structure has gradually-stepped strength weight reduction along span Spars boxed inside semi-symmetrical ribs bump-free covering surface Center planking dihedral details omitted clarity spar structure 3/16 light balsa core capped 3/16 sq spruce near root hard 3/16 sq balsa outward Note staggered transition points spruce-to-balsa caps Spar sides reinforced 1/64 ply center ending outward-staggered points Ribs 1/16 balsafirm root lighter outward aileron actually hollow capped balsa triangular structure resulting cutting along length hollow TE assembly Plastic tape hinging very easy install Position covered surfaces 1/32 1/16 apart allow bind-free operation cover side continuous strip tape half width surface Before applying tape make sure covering material firmly adhered wood beneath ittoo late apply heat after tape place Add few tape doublers other side sticky side inward touches sticky side first tape gap area snap hinged surface can folded back itself along first tape hinge line otherwise fold tape strip over thin metal strip sticky side out insert author uses tape doublers near root tip movable surface two along length depending upon size plane Nobody ever likes hear fact everyone has developed bad life however kits designed habits such kits virtual lumberfor glow engine power Over years glow busses worse foam farms see engines have grown tremendously power usually doesnt matter too much output given displacement along Continued page 80 Modified box fuselage assembly has open structure top bottom aft wing loca tion typical structure has 1/16 sheet sides 1/8 sq strip vertical stiffenersstopping top bottom sheet After sides joined rear 1/16 x / cross strips added verticals top bottom Lengths 1/16 x added along four edges cap side sheeting verticals cross braces partially Finally 1/16 x /4 strips laid flat cap vertical cross strips multi-piece structure very light strong easy CyA glue Dont let complicated description scare trying April 1984 79 fA- P [/32 1/16 PLASTIC TAPE FULL LGTH STICKY SIDE USE THIN METAL STRIP TOTRIM OF F AFT PUSH FOLD UP TO TOP TAPEINSTALLATION 2-4 PLACES -r cUijriccIic] 322 So Gallatin RdMadison TN 37115 615 868-6811V Mon thru Sat 900am 500pm FUTABA RADIO SALE~k Because care REPAIR SERVICE FOR AIIradiosystemsar0prBchBCk0df& S proper operation prior shipment RADIO SYSTEMS HOBBY LOBBYFP-713K 72FM5-128 Iist$38995$24 FUTABA ROYAL E K LOG CT RO LFP-70K 72AM5-281ist5359SS. $22500 FUTABA T EP-SOK 72FM 5-128 IistS3l99$. $20 00 ACCESSORIES FOR TP-50K 72AM S-28IistS2899$ . 50 HOBBY SHACKFP-4LV$13 S-28servosIist$19995. $11500MOST RADIOS ROYAL LINEAdd $295 Prepaid Mastercard Visa COD $495 Tenn residents add 575% tanVISA WILLIATMSACCESSORIS BROTHERS ________________ 4 PILOTS STANDARD TSMANinfu WHEEL NG TARY VINTAGE TH BALLOON EN AGE 4 ENGINES PRATT & WHITNEY HT HONE PARTS HITNEY HONE PRAtT WRIGHT E GUNS LEWISVICKERS DAU BELILIM SEND $1 FOR FULLY ILLUSTRATED CATALOG4LJAa DEPT MA 1 u IAWNEE ST SAN MARCOS CALIFORNIA 92069 glowan extra pound two often goes un noticed Its easy change nitro level tank size engine size Elec tric So youll need forget kits As might expect excep tions Some kits especially gliders adapt fairly easily electric power majority kits readily convert Electric lots kit designs look like excellent candidates quiet mo tivation Thus have some favorite glow-engine kit plans wonder Elec tric version would possible just pay tention series have desire convey enough insight information reasonably-skilled modeler can deter beforehand what needed assure Electric success other extreme some kits intended Electric have per sonally seen several including Astro Porterfield Astro Sport shoulder-wing ver sion Leisure Playboy Larry Jolly Electricus Youd have work hard go wrong few other kits Electric dont have upfront familiarity cant com ment Paradoxically relatively few kits ever-increasing number fine Electric model designs appearing modeling magazines Ive personally seen several perform fly very well course must scratchbuilding nature Sometimes good magazine design becomes kit Porterfield example understand Wasp its way being kitted As what I nearly always design build scratch Lately however Ive taken interest some kits modifications might needed con vert good Electric models Some Construction Guidelines Now weve seen hard data vital statistics rules thumb planes fly well lets look beneath covering see theyre put together Lets start wing tend divide three groups gliders aero batic flying other kinds flying Electric-powered model glider wings can have similarities differences Sailplanes Both types have relatively high aspect ratios Electric glider must support mass power installation Sailplane must tolerate tow air foil can favorite either case Covering can same Whats really different Weight Some weight Sail plane less wont really matter times planes ballasted way Electric chal lenging difference Lets get some details tend avoid discourage plugtogether wings obviously makes large Electric gliders bit problem What comes down chosen design wont fit family buggy singlepiece wing must made piece will have weight Continued page 82 80 Model Aviation fL15 FULL LINE METAL SPECIALISTS penalty several ounces can mod erated bit wont have tow loads contend hardware associated holding wing parts together can lighter size weight Unfortunately personally dont have hands-on exam ples area can offer observation generalization Ive seen fair share wings fold failure almost always near wing center exactly what expect bending moment greatest obviously thats place invest some weight strength follows made near-center region super strong next failure location would further out just past super-strong part failure would less apt happen because bending moment less wing center could simply make next region part past super-strong center lust very strong next possibility fail ure would occur further out wing panel discussion has treated discrete regions wing should clear effects really gradual nature really should thought steps effect what really needed wing structure having relatively smooth variation strength weight super strong very middle very little strength tip What Ive said hardly new stuffs known seems forever prac ticality matter its much easier build wing relatively uniform strength along span gradually di minishing strength simpler wing heavier thats what about build glider wings some others well step-wise varying strength technique gradually reduce wing strength weight root tip series small steps simple compromise between virtually no variation smooth tapering variation latter can ex tremely tedious time-consuming build step-wise approach easy understand though cumbersome describe words wings usually all-balsa root tip supplemented varying-length spruce additions balsa leading edge eable soft trail ing edge usually hollow-triangle type made sheet balsa top bottom filler strips between ribs front rear trailing edge capped simple balsa strip except near center spruce cap used tolerates wing rubberbands much better So far theres nothing unusual big difference comes spars make hard balsa rectangular cross section As now common practice spruce two laid flat top bottom ribs near point maximum thickness Vertical-grain balsa webs installed tween top bottom spars along entire span legitimate Continued page 166 82 Model Aviation SUPERwings DIVISION OF HI JOHNSON MODEL PRODUCTS 11015 GLENOAKS BLVD PACOIMA CA 91331 SAILPLANE COMPONENTS CREATE YOUR OWN SUPER GLIDER WING FOAM CORES Floater Thermal & Slope FUSELAGES LUSTROLEEN 2 Meter Standard Open & Scale STAB FOAM CORES Rudder & Fin Cores COVERING MATERIALS White skin & Lustroleen WING RODS Wing Tongue Kits FOR HI JOHNSONS PORTFOLIO PRICE SHEET & ORDER FORM about sailplane construction & design using foam & plastic SEND $250 CHECK OR MO CA RES ADD SALES TAX enough clearance properly strike pro peller am enclosing two photographs showing different methods starting method flip engine forward having compression set pro peller blade two oclock position slapping propeller extremely hard engine starts flip Another method flip engine backwards strik ing propeller very close hub propeller must set horizontal parallel ground method produce satis factory results Certainly pilot must job bringing plane substantial speed getting out pits back air shortest possible interval time certainly cannot emphasize impor tance thorough complete practicing improve overall race times Know racing-circle markings Finally find competitors mark off standard circle AMA specifications use practice cases flying school parking lots etc impera tive use either chalk spray paint owner will allow mark off proper center circle landing circle pitting area Practicing under standard circle conditions improves relationship between pilot pitman since landings takeoffs done same circle atmosphere will used under competitive situa tions NEW Tartan Twin Muffler Set Allows adjustment carb running $3995 400 RPM increase over stock As always comments solicited appreciated John C Ballard 10102 Kimblewick Dr Louisville KY 40223 Electrics/Kopski Continued aoe 82 weight saving quarter ouncing because wings dont fold tips Two additional balsa spars used top bottom about halfway between main spars trailing edge latter spars can partial span so-called stub spars Like main spar pair stub spars also webbed part length Usually bottom spar stub pair continued full span supporting ribs use stub spar seems like obvious extension now-common main I-beam some reason commonly used departure established prac tice light easy adds great deal strength high aspect ratio wings stub spars may bit unusual big difference comes now four spars get spruce doublers staggered length beginning root extending outward along main panels stopping dif ferent rib stations minimizes amount comparatively heavy material putting its strength will gooddistributed step-wise center outward Most Sailplane wings sim 3-FUNCTION ACCUETACH ITM Lb LCD Tachometer w/dual scale capability lOX bOX @ Digital Voltmeter load /5 && checking/cycling TX/RX battery combos ACCU-TACHI torquick charging operation w~9 7 9aitt Send check Noror money order Ca t add 600 tax PO Box 70956 AVIONRSS Sunnyvale CA INC94086 ply use spruce way sparstrue indiscretion true overkill inverted quarter ouncing Lets describe example Its Spec tra Soar wing 8-in chord 67-in span rectangular planform poly dihedral main panels 20 long tip panels 13 ribs spaced 21/2 relatively light Ak balsa four hard balsa spars Vt X /4 main pair goes full span although balsa used tip panel spars also rela tively light stub spar structure 121/2 long five ribs main spar webbing covers four ribs stub spar webbing three spruce spar doublers square glued alongside balsa spars bottom main spar doubler five ribs long top four ribs long bottom stub spar doubler three ribs long top two ribs long particular example spruce doubler spars located TE side balsa spars full-depth Vik ply wood dihedral barces 2-in length glued spruce pieces form super strong center dihedral joint short dihedral brace also used behind balsa leading edge wing center planked over rib bay panel iA6 balsa top bottom done before dihedral joint made allowing mating surfaces snded flat tight fit maximum spar planking end-grain contact produce truly strong dihedral Continued page 168 Fine Quality Flying Models ~_5~ V Catalog $150 98 RUBBER POWER KITS plus Gliders CIL RIC Accessories Books 444e 44 MAJESTIC MODELS 3273 West 129th Street Cleveland Ohio 44111 166 Model Aviation PK PRODUCTS Specializing Quadra/Zenoah Sales Service PO Box 6226 Hayward CA 94544 Tel 415 5B1-4277 Eves H & K Superstarters Q-35$2995 Q-50$2995 MAG II$3495 Super Hustler$3495 Zenoah$2995 Tartan Twin$3995 DEALER INQUIRIES IN V/TED ALL ORDERS ADD $150 POSTAGE & HANDLING CALIF RES ADD SALES TAX TV GLOW lire cdl PLUGS NEW IMPROVED High Performance Glow Element Blow Proof Seal Six Types 3 Heat Ranges Longer Life Only $129 Swanson Associates PO Box 151E~ Since 7948 Wayne NJ 07470 Perma-Grit Litetime * Carbide Sanding Tools Tungsten Carbide grit est material next diamond Tungsten carsido grit brazed steel 9 long tool use no balsa hardwooOs bborglass beaded foamo epooc fliers pleoiglasAcerago Meeters Use excellent tools modeler can use Don Dowe Professional Engineer Made USAr-tOO i1a2r C,riIri,$051 i-br Fin$655 Ask hour Dealer send cheekF-IllFiat C,$051 o MO No COOsI soC-Ill Fdiur Ca,eIFi,$055 otot irtOtS DG Productso-2eaoorco,JF,5625 209 carriands Driveella rCun/Fitnns Dayton OH 45429 r-n,ed-CoelFrnesass 15131 294-1192 residents oddt%tao NOW THERES QUICK AND EASY WAY OF CLEANING YOUR MODEL CRAFTS Super-K Model Cleaner Removes freI Residue dirt contact CUTS CLEANING TIME IN HALF Just spray model solvent wipe soft cloth paper towel SIMPLE AS THAT Leaves craft showcase clean eWoVt harm PaInts Covedngs Dues Cleor fast S Ulminatee Yek cleaning model Strong Professional Quality formula Great Model Craft Bcots Planes Helicopters Cleans Gently Protects delicate model DEALERS WANTED DOMESTIC & OVERSEAS WE EXPORT Hurryl Have product shelves time Christmas guaranteed top seller Sugg retail $550 per gallon Contact us price structures ordering information Also ask about other Super-K products Model Industry Ate Manufacturers & Major Brands DIstributors Model Engines Kits Radios & Accessories super K S orana Kings Radio Control Hobbies International 3960 West 16th Ave Hialeah Florida 33012 Phone 305 557-2024 joint glued epoxy system provides very strong wing center section gradually stepped re duction strength weight outward along span Note no two spruce spar doublers end same rib station main stub spar webs stop different ribs strength neededmostly very middle less less along span Incidentally wing also has /s sq balsa turbulators serve no primary strength function 536 sq MonoKoted wing weighs 6/3 oz supports Spectra Soars 39-oz total weight plane currently holds KRC loops-per-minute record 22 think doesnt put screws wing structure give try see wing holds up Obviously specific illustratioin just given cannot aply exactly wing Larger wings need proportionately larger wood sizes conversely smaller wings can get away lesser wood bulk basic idea what important use material resources wisely appropriately task hand Economize material weights sake dont trade off strength counts Such discretion results building time earns large re turns longer andlor better flights time spent rebuilding glider wing probably has greatest need span-wise strength because its generally higher aspect ratio re sulting large structural load other extreme aerobatic Electrics generally have stubbiest lowest aspect ratio wings Sometimes wings have partial planking over upper surface almost never have spars covering level ie have smoother surfaces illus trations show some very workable structural options As might have guessed other wingsthose Old Timers OT Scale broad category called Sportcan readily employ blends suggested con struction techniques course OT Scale dictates may preclude exercise possible options Whatever construction approach selected lose sight need keep weight low strength high could argue point mod els Electric otherwise basic differ ence Electric such con siderations essential best performance Study accompanying structural sketches refer back Part 7 noting wing weights advised examples presented have least loopedsome vigorously opin ion wing cant looped yield ing its worth having Tail assemblies can very simple Most sheet balsa structures Choose fairly light warp-free wood achieve strength durability using harder cap strip material generally cap leading trailing edges ends hard balsa strips same thickness sheet material width two times thickness have found 3A2 sheet quite ade quate planes up about 3 3 lb I/f sheet works fine about 6 lb latter far Ive gone far have used number built-up tail struc tures size-for-size can made lighter solid sheet types still have adequate durability range Electrics up about 6 lb choose firm LE TE stock /4 thickness width two four times thick ness Ribs cross braces may square stock Ailerons elevators rudders have thing common need hinges Fellow flier John Hickey introduced hing ing technique several years ago have adopted 100% have several other Electric fliers Scotch brand Plastic Tape transparent tape available sev eral colors two widths makes excel lent hinges used illustrated always use -in-wide clear type pn 2t0062 because permits color MonoKote show through stuff costs about buck 125 real bargain application can purchased staionery variety hard ware stores have hundreds flights same hinges no evidence fa tigue have flown temperature extremes low 250 higher 1000F no problem tape very light strong offers added advantage closing hinge gap used shown have no idea holds up presence fuel has never failed its absence far know Fuselage construction can range very simple sheet box modified sheet box all-sheet all-stick all-sheet box simplest quickest build fuselages either modified variety all-stick Basically modified sheet box struc ture consists simple sheet sides partly open structure top bottom another example quarter ouncing Electric approach suitable applications sketches should tell story Additionally may want refer earlier parts series text photos have shown proven motor battery radio mounting techniques mounting areas require strongest struc tural materials places ma terial selection important keeping weight under control adequate strength Regarding material selection have plenty flying success /if sheet balsa sides models weighing up about 3 lb Several years ago 6-lb twin t5-powered Astrobat /8 sheet sides partial inside doublers /& ply wing skin material now consider structure have overkill course some judg ment regarding balsa grain density always important / ply wing skin very handy easy-to-use material can add tremendous strength along minimal weight di168 Model Aviation IN STOCK FOR IMMEDIATE SHIPMENT New 30 ClD QUADRA $19995 New 22 CID QUADRA $10950 ReQ 22 QUADRA $9995 Brinighelia Fiywheel$11995 Reg 22 QUADRA POWER ASSEMBLY ONLY$6450 QUADRA REPAIR 000 plan parts Jim Menner ERCOUPEPLANS $2395 KIT $23995 Jim Manner TOMAHAWKPLANS $2395 KIT $25995 Jim Menner9-BALLTRAINER PLANS $1895 KIT $9995 BALSA BASSWOOD sicenl 35% OFF Concept FLEET PLANS $2995 KIT $15995 COWL $1995 FLOATS 361/5 scale cores $1750 conspiete kit $3950 FLOATS 49 scalecores $2195 conspiete kit $4795 1$ WWl WHEELS $2595 P&W CYIS FLEETI6I$2596 PLANS SUPER STEARMAN Godfrey $2895 STARDUSTER TOO IBrinighellal 54 J3 CUB Neiite $2995 VOLKSPLANE Chicken Charliel$2395 COCKPIT KITS Tomahawk F4U-1 Spitfire$2295 Ercoape $2095 Stearrnan $2295 Citabria $2495 J3 Cab $2195 ME-lOS $2295 Pleat $2198 US Doadra FUEL TANKS16 oc $695 32 oc $795 FIBERGLASSARROWSHAFTS5/1603210fl9 6/81000 24-Hour. Add $250 postage Send Bank check Money Order JIM MESSERS QUALITY MODEL PRODUCTS 106 Valley View Dr Allegany NY 14706 mensional growth places model Large surface areas such fuselage side doublers can adhered contact cement smaller areas can handled conventional modeling adhesives use ply wing skin line holes balsa nose blocks serve structural motor mounts shown earlier installment Another very useful material /8 Lite Ply material poplar think stronger heavier balsa strong heavy birch ply has useful applications A-in thickness properties three-ply laminate ad vantageous often use formers structural motor mounts pictured Part 2 Whichever technique materials choose think about what youre doing pick up piece wood Spend few bucks 16-oz postage diet scale use youre building can quite educational surprising source free structural strength covering material Specif ically proper application MonoKote other plastic covering sheet balsa struc tures will add significantly finished strength durability probably case other covering materials well dont have firsthand experience call free benefit because certainly some kind finish its associ ated weight will always used thats needed claim benefit proper ap plication Loose bubbled MonoKote sheet surfaces does much good smooth evenly-adhered covering does Thus suggest pay little extra atten tion next cover sheet surface such fuselage side tail surface Virtually building now done CyA adhesives includes sticks Playboy OT few places still use epoxy favorite Hobbypoxy Formula 1 epoxy neither real fast nor real slow does excel lent job dihedral joints few other select applications dihedral joints always butt joints first doubled later mean wing centers panel completed planking etc dihedral mating sur faces sandedflat good fit LE LB spar spar planking planking nifty end-grain gets thin finger smear Formula 1 soaks 15-20 mm new batch mixed applied following surfaces held together few hours Finally dihedral braces installed Remember Part 1 said Elec tric can make better builder care ful choice materials careful fitting joints CyA can its job epoxy right places no globs please careful covering adhesion true quarter ounc ing techniques no penalties strength department minimal premium building time ever returned glow-engine flying Id still build way Next month well have continuation Planes Flying taking look some successful Electrics flown recent KRC Electric Fly events Well also develop list motors props batteries sociated operating power levels latter information combined previous sec tions rules thumb herein should allow plan own successful Elec trics time want express sincere thank letters expressing appreciation encouragementand requests information letters have resulted some new thinking part series possibly some followup articles Any questions comments etc section previous ones may directed SASE author Bob Kopski 25 West End Dr Lansdale PA 19446 Kingfisher/Perry Continued page 87 dig wing surface Vacuum wing before applying low-temperature covering film such Solar Film Flying conventional low-speed flight particularly young inexperienced pi lot prefer use forward balance point limit up-elevator model will stall Set engine idle power just sufficient maintain level flight under dead-calm conditions Normal flying conditions will require slight continued page 172 Open up new wodd modeling excitement days modelers wont settle puttering around sky hours end want loops rolls spins want quality balsa kits - parts fit right out box want Great Planes youre RIC modeler thats interested perform ance should know about extensive line over 35 kits new catalog tells whole story - sport/trainers competition pattern giant scale sport scale designed Great Plane Clip out coupon return us today enter world Great Planes ~UUVACflCOiAN P0 80372URBANANOS6SA36 069 want put some excitement modeling Send FREE 1984 Great Planes catalog kits accessoriesI NAMEI ADDRESS CITY STATE ZIPI Return Great Planes Model Mtg PO Box 7210 Urbana Illinois 61801I