THERE ARE TWO basic floatplane design concepts 1 converted land model 2 model designed start water flying Because its easier us convert ex isting designs Very little weight reduction can achieved building land model exclusive water use redesigning entire structure Designing floatplane scratch however can minimize excess weight usually added crash resistance come close desired wing loading key select right model gin adjust its characteristics configuration water operation what call mandatory op tional modifications required turn land model successful floatplane Also few what consider bet ter candidates floatplane conversion will discuss later article Mandatory modifications first push-through switch water gets switch believe will given chance its over Both Du-Bro Ernst offer push-through switches lid shaft model favorite Concluding se ries floatplanes author relays list mostly simple modifications needed make land model take water Ed Westwood 36 Model Aviation Top Large fIoatpIanes attract lots attention just like land-based cousins Robin hood 80 works weii Sig floats OS 120 four-stroke power Above author Super Kadet floats modei weighs 91/2 ib power OS 61 second required modification really addition install least water rudder Williams Brothers makes commercial unit know its too small anything over 15-powered ship rudders made %2 brass tubes held nylon nose wheel steering blocks collar bottom steering arm top Brass steel sheet rudders crimped slits tubes sweatsoldered hold firmly place Sometimes rudders will bend slight ly straightening replacing may eventually necessary Yet would rather replace rudder occasionally fabricate complicated draggy kick-up type anything hard contacted water rudders tubes bend blocks undisturbed easiest way control water rud der throtfie cable secured fu selage colored tape small aluminum tabs screwed lower longeron After bending around securing aft float strut cable sheath held onto float two nylon gear straps put small rubberband under strap before tightening cable sheath can slipped back forth alignment water rudder air rudder Still requirements third primarily low-wing models wing tachment area must sealed An exception would single-float type model spray deflected away wing attachment area benefits high wing become obvi May 1988 37 12 x 4 cut down 11 x 4 helps maxi mize 05 35s thrust Eagle 63 gorgeous Spitfire rests foam blocks protect floats sand gravel beach Low-wing planes will generally get internal soaking take dunk Como 90 comes life Paul Westons Whip Lash Unique configurations lim ited landplanes use general guidelines article help own design Taxiing right up onto ramp satisfying way cap off another great water flight Floats get particularly dinged up during rigors starting getting set go Using small ramp protects floats makes simpler ease model out water Left Use run-up table saves green knees Tom Richards starts Terrier Right George Graft Gary Gieffe get Georges Sea Guii going Originaily pubiished RCM Guli Wing George changed fussiage added fioats renamed Sea Guli Left John Suiiivan preps model French Druine Turbuient buiit Precedent kit no ionger avaliabie country Power Enya R-120 fiosts now being marketed John Right ciassic J-3 Cubs popuiarity carries over fioat fiying equaiiy weli Left A typicai water rudder controi setup Note verticai fin eniarged Goidberg Eagie 63 heip reduce excessive yaw caused fiosts Right Another nice simpie water rudder instaiiation made modified Du-Bro nose wheei gear ous since wing attachment area essen tially free spray flew Sig Cub three years totally stock condition no water problems control surfaces both hinged sealed ColorTex brings fourth mandatory item seal control surfaces hinges ways though happen like result making hinges iron-on covering material important thing sealing no matter way Incidentally cyanoacrylate adhe sive CyA isnt waterproof youd best keep mind doing sealing work fifth requirement seal pushrod exits easiest way epoxy outer plastic sheath small plywood plate exits fuselage Incidentally high-wing model has another inherent water resistant characteristic turn over sooner later happens best us will float wing top stay almost completely dry wing pushrod exits underside usually stay dry low-wing model turned over water conversely has float fu selage Waterproofing fuselage difficult best push-through switch will probably water water sealing problems low-wing model make high-wing model very attractive first Continued page 40 38 Model Aviation MS SMfl1HI ZIVDUtDWZtZZD 7555 Soo GobreI Rood codero CA 93422 450-1717 floatplane trainer subject internal waterproofing necessary considering flying salt water Ive flown salt water internal waterproofing gotten away opinion anxiety takes away fun flying fresh water soak ing dunk can easily dried out no harm done electronics What open up receiver servos blow dry Sometimes servos will still need pots swabbed alcohol blown dry second time course switch must blown dry dont forget open up battery case check moisture summary forget about internal water proofing end water flying session its good idea open up ma chine check foam packing dampness Normally thats need Optional modifications Lets cover some desirable ones starting creased tail area some land models converted floatplanes suffer loss both yaw pitch stability yaw being hardest correct model has abundance vertical horizontal stabilizer area least 10% 20% respectively wing area no change will usually needed However good-flying land model af ter being converted floatplane begins yaw wrong direction aileron applied vertical stabilizer area insuffi cient Cubs way notorious did some research concerning much additional area required Consider ing floats additional fuselages ex tensive lateral stability analysis six twinfloat models indicated have same yaw stability landplane counter parts between 28% 34% additional ver tical stabilizer area required have model under construction will become floatplane making fin area larger can accomplished easily Slightly enlarging whole vertical stabi lizer will also work discerning eye will ever notice model already built adding ventral fin sub-fin may reasonable options Insufficient horizontal pitch stability usually shows up landing flare forward center gravity CG tail stops flying before wing does nose pitches down just before model touches water can enlarge stabilizer before going o extreme try moving CU aft sealing elevator hinge line plane still sensitive try adding stabilizer tip plates theres added bonus taking approach also get vertical area process may want change somewhat larger engine take average trainer Continued page 101 40 Model Aviation $975 AVAILABLE AT AMERICAS FINEST HOBBY SHOPS $975$525 DISTRIBUTED BY 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW IcZ22ZZI Water FIying/Westwood Continued page 101 counter local hobby shop ponder ing what airplane will make best float conversion Most trainer models have wing loadings 18 oz per sq ft Adding floats will raise value about 23 25% crease assuming theres enough pow er pussycat just turned real tiger dont need tiger just yet perhaps will help know right wing load ing start recommend 20 oz per sq ft reason figure corresponds stall speed 20 mph maximum lift coefficient 12 assumed Reynolds numbers 12 about can expect results what call 20/20 machine just average power 20/20 models will jump off water less 100 ft usually around 50 no wind Add little headwind liftoff will right bird comes up step pAN5pAC Impervious Exhaust Products Eliminate Burned Up & Blown Out Silicone 1000/0 SatIsfaction Guaranteed Money Back SEND 450 per 5/B ID Coupler or55aper3/4ID DANA AEROSPACE CORP 1110 E 5th St rior WI 54880 140 Model Aviation MASTER AIRSCREW Back hobby shop look box es behind counter mentally add 25% stated flying weight compute wing loading four prob ably will jump right out Sig Cub Kadet Senior Eagle 63 Telemaster 40 last really comes Hobby Lob might hobby shop too Cub Eagle both need extra 30% vertical fin area other two will float right out box ll almost Hopefully have provided enough good stuff get down water ma chine will fly well enough win fun fly events get hooked float fly ing water site boat youll find whole lot easier land flyingand cleaner too sincere desire help add water flying site inventory ease pressure existing land facili ties Lets go F When responding advertisers mention read about ModelAviation TacticalNNVi HighA IKit Includes II Mach ne Cut ISanded Balsa Ply II Foam Parts Full S ze Rolled Plans Instruct Gu de Necessary Hardware Specifications wingspan 44 Weight 9A bs Power RK-740 ft PO Box 224071 1900 Houston TX shipping 713621-1462 RC Scale/Wischers Continued page 43 tip wood strip end wood strip resting against panel beneath instrument dial image will centered within frame photo roll Just wind film shoot No need look through viewfinder image film will exact scale model exposure After film developed have contact prints made proof prints roll readymade instrument faces favored film Kodak Tri-X system provides prints highest pos sible definition because no enlargement steps process requires camera lens quite close focusing capability can used model scales up including quarter-scale thing remember three-inch dial /3 -scale larger 35mm film frame procedure color prints local processor places camera farther away panel because prints enlarged about 37 times original negative size jumbo prints Continuing example -scale model three-inch-diameter instrument would like diameter print 60 image waxed paper ground glass should 60 -- 37 16-in-diameter exercise math intended arrive dimension will produce proper scale ratio Measure camera-to-subject dis tance image size load camera color film proceed take photos air plane distance using wood strip spacing use steel tape exposure wood strip will show up print always underneath instrument minimize direct reflections glass cov ering instrument face lower camera slightly line sight isnt right angles glass using wood strip helps have painted flat black Wearing dark clothing helps keep photographer Out reflections also take photos stand ing outside cockpit Reflections glass arent really serious since present view instru ment panel anyway Reflections can elimi nated using polarizing filter either black-and-white color systems described lens best adapted wide angle employ 35mm focal length has minimum focusing distance nine inches color process wide angle lens brings camera up close panel seat backs airplane dont interfere foregoing necessary pro ducing instrument faces correct airplane being modeled panel itself can made 062-in styrene sheet holes cut instruments have painting pan els same black crackle spray can 10 years Some instruments have bezel surrounding face Make sliced tubing strips aluminum wrapped around dowel bezel glued hole instrument face photo print glued back panel prints made glossy paper illusion glass face enhance appearance clear plastic sheet can sandwiched between face panel set plastic discs bezels add depth instrument face make Continued page 142 &4ntique Series High Performance Propeller Distinctive Shape new Antique Series features undercambered turbo-style blades distinctive scimitar shape series specially designed 60 120 two four stroke applica tions Made high visibility gold glass-filled nylon modeler looking quality high performance Sizes 12x6 13x6 14x7 16x7 WINDSOR PROPELLER CO 384 Tesconi Court Santa Rosa CA 95401
Edition: Model Aviation - 1988/05
Page Numbers: 36, 37, 38, 40, 101, 140
THERE ARE TWO basic floatplane design concepts 1 converted land model 2 model designed start water flying Because its easier us convert ex isting designs Very little weight reduction can achieved building land model exclusive water use redesigning entire structure Designing floatplane scratch however can minimize excess weight usually added crash resistance come close desired wing loading key select right model gin adjust its characteristics configuration water operation what call mandatory op tional modifications required turn land model successful floatplane Also few what consider bet ter candidates floatplane conversion will discuss later article Mandatory modifications first push-through switch water gets switch believe will given chance its over Both Du-Bro Ernst offer push-through switches lid shaft model favorite Concluding se ries floatplanes author relays list mostly simple modifications needed make land model take water Ed Westwood 36 Model Aviation Top Large fIoatpIanes attract lots attention just like land-based cousins Robin hood 80 works weii Sig floats OS 120 four-stroke power Above author Super Kadet floats modei weighs 91/2 ib power OS 61 second required modification really addition install least water rudder Williams Brothers makes commercial unit know its too small anything over 15-powered ship rudders made %2 brass tubes held nylon nose wheel steering blocks collar bottom steering arm top Brass steel sheet rudders crimped slits tubes sweatsoldered hold firmly place Sometimes rudders will bend slight ly straightening replacing may eventually necessary Yet would rather replace rudder occasionally fabricate complicated draggy kick-up type anything hard contacted water rudders tubes bend blocks undisturbed easiest way control water rud der throtfie cable secured fu selage colored tape small aluminum tabs screwed lower longeron After bending around securing aft float strut cable sheath held onto float two nylon gear straps put small rubberband under strap before tightening cable sheath can slipped back forth alignment water rudder air rudder Still requirements third primarily low-wing models wing tachment area must sealed An exception would single-float type model spray deflected away wing attachment area benefits high wing become obvi May 1988 37 12 x 4 cut down 11 x 4 helps maxi mize 05 35s thrust Eagle 63 gorgeous Spitfire rests foam blocks protect floats sand gravel beach Low-wing planes will generally get internal soaking take dunk Como 90 comes life Paul Westons Whip Lash Unique configurations lim ited landplanes use general guidelines article help own design Taxiing right up onto ramp satisfying way cap off another great water flight Floats get particularly dinged up during rigors starting getting set go Using small ramp protects floats makes simpler ease model out water Left Use run-up table saves green knees Tom Richards starts Terrier Right George Graft Gary Gieffe get Georges Sea Guii going Originaily pubiished RCM Guli Wing George changed fussiage added fioats renamed Sea Guli Left John Suiiivan preps model French Druine Turbuient buiit Precedent kit no ionger avaliabie country Power Enya R-120 fiosts now being marketed John Right ciassic J-3 Cubs popuiarity carries over fioat fiying equaiiy weli Left A typicai water rudder controi setup Note verticai fin eniarged Goidberg Eagie 63 heip reduce excessive yaw caused fiosts Right Another nice simpie water rudder instaiiation made modified Du-Bro nose wheei gear ous since wing attachment area essen tially free spray flew Sig Cub three years totally stock condition no water problems control surfaces both hinged sealed ColorTex brings fourth mandatory item seal control surfaces hinges ways though happen like result making hinges iron-on covering material important thing sealing no matter way Incidentally cyanoacrylate adhe sive CyA isnt waterproof youd best keep mind doing sealing work fifth requirement seal pushrod exits easiest way epoxy outer plastic sheath small plywood plate exits fuselage Incidentally high-wing model has another inherent water resistant characteristic turn over sooner later happens best us will float wing top stay almost completely dry wing pushrod exits underside usually stay dry low-wing model turned over water conversely has float fu selage Waterproofing fuselage difficult best push-through switch will probably water water sealing problems low-wing model make high-wing model very attractive first Continued page 40 38 Model Aviation MS SMfl1HI ZIVDUtDWZtZZD 7555 Soo GobreI Rood codero CA 93422 450-1717 floatplane trainer subject internal waterproofing necessary considering flying salt water Ive flown salt water internal waterproofing gotten away opinion anxiety takes away fun flying fresh water soak ing dunk can easily dried out no harm done electronics What open up receiver servos blow dry Sometimes servos will still need pots swabbed alcohol blown dry second time course switch must blown dry dont forget open up battery case check moisture summary forget about internal water proofing end water flying session its good idea open up ma chine check foam packing dampness Normally thats need Optional modifications Lets cover some desirable ones starting creased tail area some land models converted floatplanes suffer loss both yaw pitch stability yaw being hardest correct model has abundance vertical horizontal stabilizer area least 10% 20% respectively wing area no change will usually needed However good-flying land model af ter being converted floatplane begins yaw wrong direction aileron applied vertical stabilizer area insuffi cient Cubs way notorious did some research concerning much additional area required Consider ing floats additional fuselages ex tensive lateral stability analysis six twinfloat models indicated have same yaw stability landplane counter parts between 28% 34% additional ver tical stabilizer area required have model under construction will become floatplane making fin area larger can accomplished easily Slightly enlarging whole vertical stabi lizer will also work discerning eye will ever notice model already built adding ventral fin sub-fin may reasonable options Insufficient horizontal pitch stability usually shows up landing flare forward center gravity CG tail stops flying before wing does nose pitches down just before model touches water can enlarge stabilizer before going o extreme try moving CU aft sealing elevator hinge line plane still sensitive try adding stabilizer tip plates theres added bonus taking approach also get vertical area process may want change somewhat larger engine take average trainer Continued page 101 40 Model Aviation $975 AVAILABLE AT AMERICAS FINEST HOBBY SHOPS $975$525 DISTRIBUTED BY 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW IcZ22ZZI Water FIying/Westwood Continued page 101 counter local hobby shop ponder ing what airplane will make best float conversion Most trainer models have wing loadings 18 oz per sq ft Adding floats will raise value about 23 25% crease assuming theres enough pow er pussycat just turned real tiger dont need tiger just yet perhaps will help know right wing load ing start recommend 20 oz per sq ft reason figure corresponds stall speed 20 mph maximum lift coefficient 12 assumed Reynolds numbers 12 about can expect results what call 20/20 machine just average power 20/20 models will jump off water less 100 ft usually around 50 no wind Add little headwind liftoff will right bird comes up step pAN5pAC Impervious Exhaust Products Eliminate Burned Up & Blown Out Silicone 1000/0 SatIsfaction Guaranteed Money Back SEND 450 per 5/B ID Coupler or55aper3/4ID DANA AEROSPACE CORP 1110 E 5th St rior WI 54880 140 Model Aviation MASTER AIRSCREW Back hobby shop look box es behind counter mentally add 25% stated flying weight compute wing loading four prob ably will jump right out Sig Cub Kadet Senior Eagle 63 Telemaster 40 last really comes Hobby Lob might hobby shop too Cub Eagle both need extra 30% vertical fin area other two will float right out box ll almost Hopefully have provided enough good stuff get down water ma chine will fly well enough win fun fly events get hooked float fly ing water site boat youll find whole lot easier land flyingand cleaner too sincere desire help add water flying site inventory ease pressure existing land facili ties Lets go F When responding advertisers mention read about ModelAviation TacticalNNVi HighA IKit Includes II Mach ne Cut ISanded Balsa Ply II Foam Parts Full S ze Rolled Plans Instruct Gu de Necessary Hardware Specifications wingspan 44 Weight 9A bs Power RK-740 ft PO Box 224071 1900 Houston TX shipping 713621-1462 RC Scale/Wischers Continued page 43 tip wood strip end wood strip resting against panel beneath instrument dial image will centered within frame photo roll Just wind film shoot No need look through viewfinder image film will exact scale model exposure After film developed have contact prints made proof prints roll readymade instrument faces favored film Kodak Tri-X system provides prints highest pos sible definition because no enlargement steps process requires camera lens quite close focusing capability can used model scales up including quarter-scale thing remember three-inch dial /3 -scale larger 35mm film frame procedure color prints local processor places camera farther away panel because prints enlarged about 37 times original negative size jumbo prints Continuing example -scale model three-inch-diameter instrument would like diameter print 60 image waxed paper ground glass should 60 -- 37 16-in-diameter exercise math intended arrive dimension will produce proper scale ratio Measure camera-to-subject dis tance image size load camera color film proceed take photos air plane distance using wood strip spacing use steel tape exposure wood strip will show up print always underneath instrument minimize direct reflections glass cov ering instrument face lower camera slightly line sight isnt right angles glass using wood strip helps have painted flat black Wearing dark clothing helps keep photographer Out reflections also take photos stand ing outside cockpit Reflections glass arent really serious since present view instru ment panel anyway Reflections can elimi nated using polarizing filter either black-and-white color systems described lens best adapted wide angle employ 35mm focal length has minimum focusing distance nine inches color process wide angle lens brings camera up close panel seat backs airplane dont interfere foregoing necessary pro ducing instrument faces correct airplane being modeled panel itself can made 062-in styrene sheet holes cut instruments have painting pan els same black crackle spray can 10 years Some instruments have bezel surrounding face Make sliced tubing strips aluminum wrapped around dowel bezel glued hole instrument face photo print glued back panel prints made glossy paper illusion glass face enhance appearance clear plastic sheet can sandwiched between face panel set plastic discs bezels add depth instrument face make Continued page 142 &4ntique Series High Performance Propeller Distinctive Shape new Antique Series features undercambered turbo-style blades distinctive scimitar shape series specially designed 60 120 two four stroke applica tions Made high visibility gold glass-filled nylon modeler looking quality high performance Sizes 12x6 13x6 14x7 16x7 WINDSOR PROPELLER CO 384 Tesconi Court Santa Rosa CA 95401
Edition: Model Aviation - 1988/05
Page Numbers: 36, 37, 38, 40, 101, 140
THERE ARE TWO basic floatplane design concepts 1 converted land model 2 model designed start water flying Because its easier us convert ex isting designs Very little weight reduction can achieved building land model exclusive water use redesigning entire structure Designing floatplane scratch however can minimize excess weight usually added crash resistance come close desired wing loading key select right model gin adjust its characteristics configuration water operation what call mandatory op tional modifications required turn land model successful floatplane Also few what consider bet ter candidates floatplane conversion will discuss later article Mandatory modifications first push-through switch water gets switch believe will given chance its over Both Du-Bro Ernst offer push-through switches lid shaft model favorite Concluding se ries floatplanes author relays list mostly simple modifications needed make land model take water Ed Westwood 36 Model Aviation Top Large fIoatpIanes attract lots attention just like land-based cousins Robin hood 80 works weii Sig floats OS 120 four-stroke power Above author Super Kadet floats modei weighs 91/2 ib power OS 61 second required modification really addition install least water rudder Williams Brothers makes commercial unit know its too small anything over 15-powered ship rudders made %2 brass tubes held nylon nose wheel steering blocks collar bottom steering arm top Brass steel sheet rudders crimped slits tubes sweatsoldered hold firmly place Sometimes rudders will bend slight ly straightening replacing may eventually necessary Yet would rather replace rudder occasionally fabricate complicated draggy kick-up type anything hard contacted water rudders tubes bend blocks undisturbed easiest way control water rud der throtfie cable secured fu selage colored tape small aluminum tabs screwed lower longeron After bending around securing aft float strut cable sheath held onto float two nylon gear straps put small rubberband under strap before tightening cable sheath can slipped back forth alignment water rudder air rudder Still requirements third primarily low-wing models wing tachment area must sealed An exception would single-float type model spray deflected away wing attachment area benefits high wing become obvi May 1988 37 12 x 4 cut down 11 x 4 helps maxi mize 05 35s thrust Eagle 63 gorgeous Spitfire rests foam blocks protect floats sand gravel beach Low-wing planes will generally get internal soaking take dunk Como 90 comes life Paul Westons Whip Lash Unique configurations lim ited landplanes use general guidelines article help own design Taxiing right up onto ramp satisfying way cap off another great water flight Floats get particularly dinged up during rigors starting getting set go Using small ramp protects floats makes simpler ease model out water Left Use run-up table saves green knees Tom Richards starts Terrier Right George Graft Gary Gieffe get Georges Sea Guii going Originaily pubiished RCM Guli Wing George changed fussiage added fioats renamed Sea Guli Left John Suiiivan preps model French Druine Turbuient buiit Precedent kit no ionger avaliabie country Power Enya R-120 fiosts now being marketed John Right ciassic J-3 Cubs popuiarity carries over fioat fiying equaiiy weli Left A typicai water rudder controi setup Note verticai fin eniarged Goidberg Eagie 63 heip reduce excessive yaw caused fiosts Right Another nice simpie water rudder instaiiation made modified Du-Bro nose wheei gear ous since wing attachment area essen tially free spray flew Sig Cub three years totally stock condition no water problems control surfaces both hinged sealed ColorTex brings fourth mandatory item seal control surfaces hinges ways though happen like result making hinges iron-on covering material important thing sealing no matter way Incidentally cyanoacrylate adhe sive CyA isnt waterproof youd best keep mind doing sealing work fifth requirement seal pushrod exits easiest way epoxy outer plastic sheath small plywood plate exits fuselage Incidentally high-wing model has another inherent water resistant characteristic turn over sooner later happens best us will float wing top stay almost completely dry wing pushrod exits underside usually stay dry low-wing model turned over water conversely has float fu selage Waterproofing fuselage difficult best push-through switch will probably water water sealing problems low-wing model make high-wing model very attractive first Continued page 40 38 Model Aviation MS SMfl1HI ZIVDUtDWZtZZD 7555 Soo GobreI Rood codero CA 93422 450-1717 floatplane trainer subject internal waterproofing necessary considering flying salt water Ive flown salt water internal waterproofing gotten away opinion anxiety takes away fun flying fresh water soak ing dunk can easily dried out no harm done electronics What open up receiver servos blow dry Sometimes servos will still need pots swabbed alcohol blown dry second time course switch must blown dry dont forget open up battery case check moisture summary forget about internal water proofing end water flying session its good idea open up ma chine check foam packing dampness Normally thats need Optional modifications Lets cover some desirable ones starting creased tail area some land models converted floatplanes suffer loss both yaw pitch stability yaw being hardest correct model has abundance vertical horizontal stabilizer area least 10% 20% respectively wing area no change will usually needed However good-flying land model af ter being converted floatplane begins yaw wrong direction aileron applied vertical stabilizer area insuffi cient Cubs way notorious did some research concerning much additional area required Consider ing floats additional fuselages ex tensive lateral stability analysis six twinfloat models indicated have same yaw stability landplane counter parts between 28% 34% additional ver tical stabilizer area required have model under construction will become floatplane making fin area larger can accomplished easily Slightly enlarging whole vertical stabi lizer will also work discerning eye will ever notice model already built adding ventral fin sub-fin may reasonable options Insufficient horizontal pitch stability usually shows up landing flare forward center gravity CG tail stops flying before wing does nose pitches down just before model touches water can enlarge stabilizer before going o extreme try moving CU aft sealing elevator hinge line plane still sensitive try adding stabilizer tip plates theres added bonus taking approach also get vertical area process may want change somewhat larger engine take average trainer Continued page 101 40 Model Aviation $975 AVAILABLE AT AMERICAS FINEST HOBBY SHOPS $975$525 DISTRIBUTED BY 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW IcZ22ZZI Water FIying/Westwood Continued page 101 counter local hobby shop ponder ing what airplane will make best float conversion Most trainer models have wing loadings 18 oz per sq ft Adding floats will raise value about 23 25% crease assuming theres enough pow er pussycat just turned real tiger dont need tiger just yet perhaps will help know right wing load ing start recommend 20 oz per sq ft reason figure corresponds stall speed 20 mph maximum lift coefficient 12 assumed Reynolds numbers 12 about can expect results what call 20/20 machine just average power 20/20 models will jump off water less 100 ft usually around 50 no wind Add little headwind liftoff will right bird comes up step pAN5pAC Impervious Exhaust Products Eliminate Burned Up & Blown Out Silicone 1000/0 SatIsfaction Guaranteed Money Back SEND 450 per 5/B ID Coupler or55aper3/4ID DANA AEROSPACE CORP 1110 E 5th St rior WI 54880 140 Model Aviation MASTER AIRSCREW Back hobby shop look box es behind counter mentally add 25% stated flying weight compute wing loading four prob ably will jump right out Sig Cub Kadet Senior Eagle 63 Telemaster 40 last really comes Hobby Lob might hobby shop too Cub Eagle both need extra 30% vertical fin area other two will float right out box ll almost Hopefully have provided enough good stuff get down water ma chine will fly well enough win fun fly events get hooked float fly ing water site boat youll find whole lot easier land flyingand cleaner too sincere desire help add water flying site inventory ease pressure existing land facili ties Lets go F When responding advertisers mention read about ModelAviation TacticalNNVi HighA IKit Includes II Mach ne Cut ISanded Balsa Ply II Foam Parts Full S ze Rolled Plans Instruct Gu de Necessary Hardware Specifications wingspan 44 Weight 9A bs Power RK-740 ft PO Box 224071 1900 Houston TX shipping 713621-1462 RC Scale/Wischers Continued page 43 tip wood strip end wood strip resting against panel beneath instrument dial image will centered within frame photo roll Just wind film shoot No need look through viewfinder image film will exact scale model exposure After film developed have contact prints made proof prints roll readymade instrument faces favored film Kodak Tri-X system provides prints highest pos sible definition because no enlargement steps process requires camera lens quite close focusing capability can used model scales up including quarter-scale thing remember three-inch dial /3 -scale larger 35mm film frame procedure color prints local processor places camera farther away panel because prints enlarged about 37 times original negative size jumbo prints Continuing example -scale model three-inch-diameter instrument would like diameter print 60 image waxed paper ground glass should 60 -- 37 16-in-diameter exercise math intended arrive dimension will produce proper scale ratio Measure camera-to-subject dis tance image size load camera color film proceed take photos air plane distance using wood strip spacing use steel tape exposure wood strip will show up print always underneath instrument minimize direct reflections glass cov ering instrument face lower camera slightly line sight isnt right angles glass using wood strip helps have painted flat black Wearing dark clothing helps keep photographer Out reflections also take photos stand ing outside cockpit Reflections glass arent really serious since present view instru ment panel anyway Reflections can elimi nated using polarizing filter either black-and-white color systems described lens best adapted wide angle employ 35mm focal length has minimum focusing distance nine inches color process wide angle lens brings camera up close panel seat backs airplane dont interfere foregoing necessary pro ducing instrument faces correct airplane being modeled panel itself can made 062-in styrene sheet holes cut instruments have painting pan els same black crackle spray can 10 years Some instruments have bezel surrounding face Make sliced tubing strips aluminum wrapped around dowel bezel glued hole instrument face photo print glued back panel prints made glossy paper illusion glass face enhance appearance clear plastic sheet can sandwiched between face panel set plastic discs bezels add depth instrument face make Continued page 142 &4ntique Series High Performance Propeller Distinctive Shape new Antique Series features undercambered turbo-style blades distinctive scimitar shape series specially designed 60 120 two four stroke applica tions Made high visibility gold glass-filled nylon modeler looking quality high performance Sizes 12x6 13x6 14x7 16x7 WINDSOR PROPELLER CO 384 Tesconi Court Santa Rosa CA 95401
Edition: Model Aviation - 1988/05
Page Numbers: 36, 37, 38, 40, 101, 140
THERE ARE TWO basic floatplane design concepts 1 converted land model 2 model designed start water flying Because its easier us convert ex isting designs Very little weight reduction can achieved building land model exclusive water use redesigning entire structure Designing floatplane scratch however can minimize excess weight usually added crash resistance come close desired wing loading key select right model gin adjust its characteristics configuration water operation what call mandatory op tional modifications required turn land model successful floatplane Also few what consider bet ter candidates floatplane conversion will discuss later article Mandatory modifications first push-through switch water gets switch believe will given chance its over Both Du-Bro Ernst offer push-through switches lid shaft model favorite Concluding se ries floatplanes author relays list mostly simple modifications needed make land model take water Ed Westwood 36 Model Aviation Top Large fIoatpIanes attract lots attention just like land-based cousins Robin hood 80 works weii Sig floats OS 120 four-stroke power Above author Super Kadet floats modei weighs 91/2 ib power OS 61 second required modification really addition install least water rudder Williams Brothers makes commercial unit know its too small anything over 15-powered ship rudders made %2 brass tubes held nylon nose wheel steering blocks collar bottom steering arm top Brass steel sheet rudders crimped slits tubes sweatsoldered hold firmly place Sometimes rudders will bend slight ly straightening replacing may eventually necessary Yet would rather replace rudder occasionally fabricate complicated draggy kick-up type anything hard contacted water rudders tubes bend blocks undisturbed easiest way control water rud der throtfie cable secured fu selage colored tape small aluminum tabs screwed lower longeron After bending around securing aft float strut cable sheath held onto float two nylon gear straps put small rubberband under strap before tightening cable sheath can slipped back forth alignment water rudder air rudder Still requirements third primarily low-wing models wing tachment area must sealed An exception would single-float type model spray deflected away wing attachment area benefits high wing become obvi May 1988 37 12 x 4 cut down 11 x 4 helps maxi mize 05 35s thrust Eagle 63 gorgeous Spitfire rests foam blocks protect floats sand gravel beach Low-wing planes will generally get internal soaking take dunk Como 90 comes life Paul Westons Whip Lash Unique configurations lim ited landplanes use general guidelines article help own design Taxiing right up onto ramp satisfying way cap off another great water flight Floats get particularly dinged up during rigors starting getting set go Using small ramp protects floats makes simpler ease model out water Left Use run-up table saves green knees Tom Richards starts Terrier Right George Graft Gary Gieffe get Georges Sea Guii going Originaily pubiished RCM Guli Wing George changed fussiage added fioats renamed Sea Guli Left John Suiiivan preps model French Druine Turbuient buiit Precedent kit no ionger avaliabie country Power Enya R-120 fiosts now being marketed John Right ciassic J-3 Cubs popuiarity carries over fioat fiying equaiiy weli Left A typicai water rudder controi setup Note verticai fin eniarged Goidberg Eagie 63 heip reduce excessive yaw caused fiosts Right Another nice simpie water rudder instaiiation made modified Du-Bro nose wheei gear ous since wing attachment area essen tially free spray flew Sig Cub three years totally stock condition no water problems control surfaces both hinged sealed ColorTex brings fourth mandatory item seal control surfaces hinges ways though happen like result making hinges iron-on covering material important thing sealing no matter way Incidentally cyanoacrylate adhe sive CyA isnt waterproof youd best keep mind doing sealing work fifth requirement seal pushrod exits easiest way epoxy outer plastic sheath small plywood plate exits fuselage Incidentally high-wing model has another inherent water resistant characteristic turn over sooner later happens best us will float wing top stay almost completely dry wing pushrod exits underside usually stay dry low-wing model turned over water conversely has float fu selage Waterproofing fuselage difficult best push-through switch will probably water water sealing problems low-wing model make high-wing model very attractive first Continued page 40 38 Model Aviation MS SMfl1HI ZIVDUtDWZtZZD 7555 Soo GobreI Rood codero CA 93422 450-1717 floatplane trainer subject internal waterproofing necessary considering flying salt water Ive flown salt water internal waterproofing gotten away opinion anxiety takes away fun flying fresh water soak ing dunk can easily dried out no harm done electronics What open up receiver servos blow dry Sometimes servos will still need pots swabbed alcohol blown dry second time course switch must blown dry dont forget open up battery case check moisture summary forget about internal water proofing end water flying session its good idea open up ma chine check foam packing dampness Normally thats need Optional modifications Lets cover some desirable ones starting creased tail area some land models converted floatplanes suffer loss both yaw pitch stability yaw being hardest correct model has abundance vertical horizontal stabilizer area least 10% 20% respectively wing area no change will usually needed However good-flying land model af ter being converted floatplane begins yaw wrong direction aileron applied vertical stabilizer area insuffi cient Cubs way notorious did some research concerning much additional area required Consider ing floats additional fuselages ex tensive lateral stability analysis six twinfloat models indicated have same yaw stability landplane counter parts between 28% 34% additional ver tical stabilizer area required have model under construction will become floatplane making fin area larger can accomplished easily Slightly enlarging whole vertical stabi lizer will also work discerning eye will ever notice model already built adding ventral fin sub-fin may reasonable options Insufficient horizontal pitch stability usually shows up landing flare forward center gravity CG tail stops flying before wing does nose pitches down just before model touches water can enlarge stabilizer before going o extreme try moving CU aft sealing elevator hinge line plane still sensitive try adding stabilizer tip plates theres added bonus taking approach also get vertical area process may want change somewhat larger engine take average trainer Continued page 101 40 Model Aviation $975 AVAILABLE AT AMERICAS FINEST HOBBY SHOPS $975$525 DISTRIBUTED BY 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW IcZ22ZZI Water FIying/Westwood Continued page 101 counter local hobby shop ponder ing what airplane will make best float conversion Most trainer models have wing loadings 18 oz per sq ft Adding floats will raise value about 23 25% crease assuming theres enough pow er pussycat just turned real tiger dont need tiger just yet perhaps will help know right wing load ing start recommend 20 oz per sq ft reason figure corresponds stall speed 20 mph maximum lift coefficient 12 assumed Reynolds numbers 12 about can expect results what call 20/20 machine just average power 20/20 models will jump off water less 100 ft usually around 50 no wind Add little headwind liftoff will right bird comes up step pAN5pAC Impervious Exhaust Products Eliminate Burned Up & Blown Out Silicone 1000/0 SatIsfaction Guaranteed Money Back SEND 450 per 5/B ID Coupler or55aper3/4ID DANA AEROSPACE CORP 1110 E 5th St rior WI 54880 140 Model Aviation MASTER AIRSCREW Back hobby shop look box es behind counter mentally add 25% stated flying weight compute wing loading four prob ably will jump right out Sig Cub Kadet Senior Eagle 63 Telemaster 40 last really comes Hobby Lob might hobby shop too Cub Eagle both need extra 30% vertical fin area other two will float right out box ll almost Hopefully have provided enough good stuff get down water ma chine will fly well enough win fun fly events get hooked float fly ing water site boat youll find whole lot easier land flyingand cleaner too sincere desire help add water flying site inventory ease pressure existing land facili ties Lets go F When responding advertisers mention read about ModelAviation TacticalNNVi HighA IKit Includes II Mach ne Cut ISanded Balsa Ply II Foam Parts Full S ze Rolled Plans Instruct Gu de Necessary Hardware Specifications wingspan 44 Weight 9A bs Power RK-740 ft PO Box 224071 1900 Houston TX shipping 713621-1462 RC Scale/Wischers Continued page 43 tip wood strip end wood strip resting against panel beneath instrument dial image will centered within frame photo roll Just wind film shoot No need look through viewfinder image film will exact scale model exposure After film developed have contact prints made proof prints roll readymade instrument faces favored film Kodak Tri-X system provides prints highest pos sible definition because no enlargement steps process requires camera lens quite close focusing capability can used model scales up including quarter-scale thing remember three-inch dial /3 -scale larger 35mm film frame procedure color prints local processor places camera farther away panel because prints enlarged about 37 times original negative size jumbo prints Continuing example -scale model three-inch-diameter instrument would like diameter print 60 image waxed paper ground glass should 60 -- 37 16-in-diameter exercise math intended arrive dimension will produce proper scale ratio Measure camera-to-subject dis tance image size load camera color film proceed take photos air plane distance using wood strip spacing use steel tape exposure wood strip will show up print always underneath instrument minimize direct reflections glass cov ering instrument face lower camera slightly line sight isnt right angles glass using wood strip helps have painted flat black Wearing dark clothing helps keep photographer Out reflections also take photos stand ing outside cockpit Reflections glass arent really serious since present view instru ment panel anyway Reflections can elimi nated using polarizing filter either black-and-white color systems described lens best adapted wide angle employ 35mm focal length has minimum focusing distance nine inches color process wide angle lens brings camera up close panel seat backs airplane dont interfere foregoing necessary pro ducing instrument faces correct airplane being modeled panel itself can made 062-in styrene sheet holes cut instruments have painting pan els same black crackle spray can 10 years Some instruments have bezel surrounding face Make sliced tubing strips aluminum wrapped around dowel bezel glued hole instrument face photo print glued back panel prints made glossy paper illusion glass face enhance appearance clear plastic sheet can sandwiched between face panel set plastic discs bezels add depth instrument face make Continued page 142 &4ntique Series High Performance Propeller Distinctive Shape new Antique Series features undercambered turbo-style blades distinctive scimitar shape series specially designed 60 120 two four stroke applica tions Made high visibility gold glass-filled nylon modeler looking quality high performance Sizes 12x6 13x6 14x7 16x7 WINDSOR PROPELLER CO 384 Tesconi Court Santa Rosa CA 95401
Edition: Model Aviation - 1988/05
Page Numbers: 36, 37, 38, 40, 101, 140
THERE ARE TWO basic floatplane design concepts 1 converted land model 2 model designed start water flying Because its easier us convert ex isting designs Very little weight reduction can achieved building land model exclusive water use redesigning entire structure Designing floatplane scratch however can minimize excess weight usually added crash resistance come close desired wing loading key select right model gin adjust its characteristics configuration water operation what call mandatory op tional modifications required turn land model successful floatplane Also few what consider bet ter candidates floatplane conversion will discuss later article Mandatory modifications first push-through switch water gets switch believe will given chance its over Both Du-Bro Ernst offer push-through switches lid shaft model favorite Concluding se ries floatplanes author relays list mostly simple modifications needed make land model take water Ed Westwood 36 Model Aviation Top Large fIoatpIanes attract lots attention just like land-based cousins Robin hood 80 works weii Sig floats OS 120 four-stroke power Above author Super Kadet floats modei weighs 91/2 ib power OS 61 second required modification really addition install least water rudder Williams Brothers makes commercial unit know its too small anything over 15-powered ship rudders made %2 brass tubes held nylon nose wheel steering blocks collar bottom steering arm top Brass steel sheet rudders crimped slits tubes sweatsoldered hold firmly place Sometimes rudders will bend slight ly straightening replacing may eventually necessary Yet would rather replace rudder occasionally fabricate complicated draggy kick-up type anything hard contacted water rudders tubes bend blocks undisturbed easiest way control water rud der throtfie cable secured fu selage colored tape small aluminum tabs screwed lower longeron After bending around securing aft float strut cable sheath held onto float two nylon gear straps put small rubberband under strap before tightening cable sheath can slipped back forth alignment water rudder air rudder Still requirements third primarily low-wing models wing tachment area must sealed An exception would single-float type model spray deflected away wing attachment area benefits high wing become obvi May 1988 37 12 x 4 cut down 11 x 4 helps maxi mize 05 35s thrust Eagle 63 gorgeous Spitfire rests foam blocks protect floats sand gravel beach Low-wing planes will generally get internal soaking take dunk Como 90 comes life Paul Westons Whip Lash Unique configurations lim ited landplanes use general guidelines article help own design Taxiing right up onto ramp satisfying way cap off another great water flight Floats get particularly dinged up during rigors starting getting set go Using small ramp protects floats makes simpler ease model out water Left Use run-up table saves green knees Tom Richards starts Terrier Right George Graft Gary Gieffe get Georges Sea Guii going Originaily pubiished RCM Guli Wing George changed fussiage added fioats renamed Sea Guli Left John Suiiivan preps model French Druine Turbuient buiit Precedent kit no ionger avaliabie country Power Enya R-120 fiosts now being marketed John Right ciassic J-3 Cubs popuiarity carries over fioat fiying equaiiy weli Left A typicai water rudder controi setup Note verticai fin eniarged Goidberg Eagie 63 heip reduce excessive yaw caused fiosts Right Another nice simpie water rudder instaiiation made modified Du-Bro nose wheei gear ous since wing attachment area essen tially free spray flew Sig Cub three years totally stock condition no water problems control surfaces both hinged sealed ColorTex brings fourth mandatory item seal control surfaces hinges ways though happen like result making hinges iron-on covering material important thing sealing no matter way Incidentally cyanoacrylate adhe sive CyA isnt waterproof youd best keep mind doing sealing work fifth requirement seal pushrod exits easiest way epoxy outer plastic sheath small plywood plate exits fuselage Incidentally high-wing model has another inherent water resistant characteristic turn over sooner later happens best us will float wing top stay almost completely dry wing pushrod exits underside usually stay dry low-wing model turned over water conversely has float fu selage Waterproofing fuselage difficult best push-through switch will probably water water sealing problems low-wing model make high-wing model very attractive first Continued page 40 38 Model Aviation MS SMfl1HI ZIVDUtDWZtZZD 7555 Soo GobreI Rood codero CA 93422 450-1717 floatplane trainer subject internal waterproofing necessary considering flying salt water Ive flown salt water internal waterproofing gotten away opinion anxiety takes away fun flying fresh water soak ing dunk can easily dried out no harm done electronics What open up receiver servos blow dry Sometimes servos will still need pots swabbed alcohol blown dry second time course switch must blown dry dont forget open up battery case check moisture summary forget about internal water proofing end water flying session its good idea open up ma chine check foam packing dampness Normally thats need Optional modifications Lets cover some desirable ones starting creased tail area some land models converted floatplanes suffer loss both yaw pitch stability yaw being hardest correct model has abundance vertical horizontal stabilizer area least 10% 20% respectively wing area no change will usually needed However good-flying land model af ter being converted floatplane begins yaw wrong direction aileron applied vertical stabilizer area insuffi cient Cubs way notorious did some research concerning much additional area required Consider ing floats additional fuselages ex tensive lateral stability analysis six twinfloat models indicated have same yaw stability landplane counter parts between 28% 34% additional ver tical stabilizer area required have model under construction will become floatplane making fin area larger can accomplished easily Slightly enlarging whole vertical stabi lizer will also work discerning eye will ever notice model already built adding ventral fin sub-fin may reasonable options Insufficient horizontal pitch stability usually shows up landing flare forward center gravity CG tail stops flying before wing does nose pitches down just before model touches water can enlarge stabilizer before going o extreme try moving CU aft sealing elevator hinge line plane still sensitive try adding stabilizer tip plates theres added bonus taking approach also get vertical area process may want change somewhat larger engine take average trainer Continued page 101 40 Model Aviation $975 AVAILABLE AT AMERICAS FINEST HOBBY SHOPS $975$525 DISTRIBUTED BY 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW IcZ22ZZI Water FIying/Westwood Continued page 101 counter local hobby shop ponder ing what airplane will make best float conversion Most trainer models have wing loadings 18 oz per sq ft Adding floats will raise value about 23 25% crease assuming theres enough pow er pussycat just turned real tiger dont need tiger just yet perhaps will help know right wing load ing start recommend 20 oz per sq ft reason figure corresponds stall speed 20 mph maximum lift coefficient 12 assumed Reynolds numbers 12 about can expect results what call 20/20 machine just average power 20/20 models will jump off water less 100 ft usually around 50 no wind Add little headwind liftoff will right bird comes up step pAN5pAC Impervious Exhaust Products Eliminate Burned Up & Blown Out Silicone 1000/0 SatIsfaction Guaranteed Money Back SEND 450 per 5/B ID Coupler or55aper3/4ID DANA AEROSPACE CORP 1110 E 5th St rior WI 54880 140 Model Aviation MASTER AIRSCREW Back hobby shop look box es behind counter mentally add 25% stated flying weight compute wing loading four prob ably will jump right out Sig Cub Kadet Senior Eagle 63 Telemaster 40 last really comes Hobby Lob might hobby shop too Cub Eagle both need extra 30% vertical fin area other two will float right out box ll almost Hopefully have provided enough good stuff get down water ma chine will fly well enough win fun fly events get hooked float fly ing water site boat youll find whole lot easier land flyingand cleaner too sincere desire help add water flying site inventory ease pressure existing land facili ties Lets go F When responding advertisers mention read about ModelAviation TacticalNNVi HighA IKit Includes II Mach ne Cut ISanded Balsa Ply II Foam Parts Full S ze Rolled Plans Instruct Gu de Necessary Hardware Specifications wingspan 44 Weight 9A bs Power RK-740 ft PO Box 224071 1900 Houston TX shipping 713621-1462 RC Scale/Wischers Continued page 43 tip wood strip end wood strip resting against panel beneath instrument dial image will centered within frame photo roll Just wind film shoot No need look through viewfinder image film will exact scale model exposure After film developed have contact prints made proof prints roll readymade instrument faces favored film Kodak Tri-X system provides prints highest pos sible definition because no enlargement steps process requires camera lens quite close focusing capability can used model scales up including quarter-scale thing remember three-inch dial /3 -scale larger 35mm film frame procedure color prints local processor places camera farther away panel because prints enlarged about 37 times original negative size jumbo prints Continuing example -scale model three-inch-diameter instrument would like diameter print 60 image waxed paper ground glass should 60 -- 37 16-in-diameter exercise math intended arrive dimension will produce proper scale ratio Measure camera-to-subject dis tance image size load camera color film proceed take photos air plane distance using wood strip spacing use steel tape exposure wood strip will show up print always underneath instrument minimize direct reflections glass cov ering instrument face lower camera slightly line sight isnt right angles glass using wood strip helps have painted flat black Wearing dark clothing helps keep photographer Out reflections also take photos stand ing outside cockpit Reflections glass arent really serious since present view instru ment panel anyway Reflections can elimi nated using polarizing filter either black-and-white color systems described lens best adapted wide angle employ 35mm focal length has minimum focusing distance nine inches color process wide angle lens brings camera up close panel seat backs airplane dont interfere foregoing necessary pro ducing instrument faces correct airplane being modeled panel itself can made 062-in styrene sheet holes cut instruments have painting pan els same black crackle spray can 10 years Some instruments have bezel surrounding face Make sliced tubing strips aluminum wrapped around dowel bezel glued hole instrument face photo print glued back panel prints made glossy paper illusion glass face enhance appearance clear plastic sheet can sandwiched between face panel set plastic discs bezels add depth instrument face make Continued page 142 &4ntique Series High Performance Propeller Distinctive Shape new Antique Series features undercambered turbo-style blades distinctive scimitar shape series specially designed 60 120 two four stroke applica tions Made high visibility gold glass-filled nylon modeler looking quality high performance Sizes 12x6 13x6 14x7 16x7 WINDSOR PROPELLER CO 384 Tesconi Court Santa Rosa CA 95401
Edition: Model Aviation - 1988/05
Page Numbers: 36, 37, 38, 40, 101, 140
THERE ARE TWO basic floatplane design concepts 1 converted land model 2 model designed start water flying Because its easier us convert ex isting designs Very little weight reduction can achieved building land model exclusive water use redesigning entire structure Designing floatplane scratch however can minimize excess weight usually added crash resistance come close desired wing loading key select right model gin adjust its characteristics configuration water operation what call mandatory op tional modifications required turn land model successful floatplane Also few what consider bet ter candidates floatplane conversion will discuss later article Mandatory modifications first push-through switch water gets switch believe will given chance its over Both Du-Bro Ernst offer push-through switches lid shaft model favorite Concluding se ries floatplanes author relays list mostly simple modifications needed make land model take water Ed Westwood 36 Model Aviation Top Large fIoatpIanes attract lots attention just like land-based cousins Robin hood 80 works weii Sig floats OS 120 four-stroke power Above author Super Kadet floats modei weighs 91/2 ib power OS 61 second required modification really addition install least water rudder Williams Brothers makes commercial unit know its too small anything over 15-powered ship rudders made %2 brass tubes held nylon nose wheel steering blocks collar bottom steering arm top Brass steel sheet rudders crimped slits tubes sweatsoldered hold firmly place Sometimes rudders will bend slight ly straightening replacing may eventually necessary Yet would rather replace rudder occasionally fabricate complicated draggy kick-up type anything hard contacted water rudders tubes bend blocks undisturbed easiest way control water rud der throtfie cable secured fu selage colored tape small aluminum tabs screwed lower longeron After bending around securing aft float strut cable sheath held onto float two nylon gear straps put small rubberband under strap before tightening cable sheath can slipped back forth alignment water rudder air rudder Still requirements third primarily low-wing models wing tachment area must sealed An exception would single-float type model spray deflected away wing attachment area benefits high wing become obvi May 1988 37 12 x 4 cut down 11 x 4 helps maxi mize 05 35s thrust Eagle 63 gorgeous Spitfire rests foam blocks protect floats sand gravel beach Low-wing planes will generally get internal soaking take dunk Como 90 comes life Paul Westons Whip Lash Unique configurations lim ited landplanes use general guidelines article help own design Taxiing right up onto ramp satisfying way cap off another great water flight Floats get particularly dinged up during rigors starting getting set go Using small ramp protects floats makes simpler ease model out water Left Use run-up table saves green knees Tom Richards starts Terrier Right George Graft Gary Gieffe get Georges Sea Guii going Originaily pubiished RCM Guli Wing George changed fussiage added fioats renamed Sea Guli Left John Suiiivan preps model French Druine Turbuient buiit Precedent kit no ionger avaliabie country Power Enya R-120 fiosts now being marketed John Right ciassic J-3 Cubs popuiarity carries over fioat fiying equaiiy weli Left A typicai water rudder controi setup Note verticai fin eniarged Goidberg Eagie 63 heip reduce excessive yaw caused fiosts Right Another nice simpie water rudder instaiiation made modified Du-Bro nose wheei gear ous since wing attachment area essen tially free spray flew Sig Cub three years totally stock condition no water problems control surfaces both hinged sealed ColorTex brings fourth mandatory item seal control surfaces hinges ways though happen like result making hinges iron-on covering material important thing sealing no matter way Incidentally cyanoacrylate adhe sive CyA isnt waterproof youd best keep mind doing sealing work fifth requirement seal pushrod exits easiest way epoxy outer plastic sheath small plywood plate exits fuselage Incidentally high-wing model has another inherent water resistant characteristic turn over sooner later happens best us will float wing top stay almost completely dry wing pushrod exits underside usually stay dry low-wing model turned over water conversely has float fu selage Waterproofing fuselage difficult best push-through switch will probably water water sealing problems low-wing model make high-wing model very attractive first Continued page 40 38 Model Aviation MS SMfl1HI ZIVDUtDWZtZZD 7555 Soo GobreI Rood codero CA 93422 450-1717 floatplane trainer subject internal waterproofing necessary considering flying salt water Ive flown salt water internal waterproofing gotten away opinion anxiety takes away fun flying fresh water soak ing dunk can easily dried out no harm done electronics What open up receiver servos blow dry Sometimes servos will still need pots swabbed alcohol blown dry second time course switch must blown dry dont forget open up battery case check moisture summary forget about internal water proofing end water flying session its good idea open up ma chine check foam packing dampness Normally thats need Optional modifications Lets cover some desirable ones starting creased tail area some land models converted floatplanes suffer loss both yaw pitch stability yaw being hardest correct model has abundance vertical horizontal stabilizer area least 10% 20% respectively wing area no change will usually needed However good-flying land model af ter being converted floatplane begins yaw wrong direction aileron applied vertical stabilizer area insuffi cient Cubs way notorious did some research concerning much additional area required Consider ing floats additional fuselages ex tensive lateral stability analysis six twinfloat models indicated have same yaw stability landplane counter parts between 28% 34% additional ver tical stabilizer area required have model under construction will become floatplane making fin area larger can accomplished easily Slightly enlarging whole vertical stabi lizer will also work discerning eye will ever notice model already built adding ventral fin sub-fin may reasonable options Insufficient horizontal pitch stability usually shows up landing flare forward center gravity CG tail stops flying before wing does nose pitches down just before model touches water can enlarge stabilizer before going o extreme try moving CU aft sealing elevator hinge line plane still sensitive try adding stabilizer tip plates theres added bonus taking approach also get vertical area process may want change somewhat larger engine take average trainer Continued page 101 40 Model Aviation $975 AVAILABLE AT AMERICAS FINEST HOBBY SHOPS $975$525 DISTRIBUTED BY 2 happen fall directly cent ers adjacent RC channels 3 spaced same two test transmitters example intermodula tion-generated channels spaced 120 kHz apart because generating transmitters spaced 120 kHz apart THIS IS PRETTY GOOD SIMULATION OF FLYING NEAR CROWD OF RC TRANSMITTERS OPERATING ON ADJA CENT CHANNELS has advantage dont need crowd transmitters simulation So now will call burt-to-butt test setup FLS Flight Line Simulation test FLS test easy way discriminate tween receivers show good resistance saturation crowd adjacent-channel transmitters dont Based data George Steiner has accumulated tests hundreds RC receivers best designs sold prior 1988 wont tolerate inter fering signal about 30 dB above minimum signal required good control true whether interferer 10 kHz 500 kHz away 30 dB power level translates minimum FLS test distance about 30 ft receiv er between interferers control transmitter 200 ft away test setup yields multiplier 200-30130 Remember number intention continues to present simple field test looks worst case doesnt need special test equipment worst case occurs stand alone couple hundred feet crowd transmitters op erating adjacent channels Looking in-service reality may have wondered some people can stand sideby-side group fly obvious inter ference problems can tell get away because have good transmitters receivers Crowding transmitters together creates ideal conditions ADJACENT-CHANNEL interfer ence particularly OWBAM RC sys tems designed 80-kHz matrix operating 40-kHz matrix Lets look Figure 3 see what hap pens put OWBAM transmitter next new FM transmitter operating channel 40 kHz away Note intermodu lation signals spot other adjacent chan nels buried sidebands rel atively sloppy AM transmitter As can plain ly see 31M isnt major problem standing close flying problem OWBAM transmitters sidebands As better transmitters replace OWBAM transmitters interference problems 40 kHz raster par ticularly part instituted 1988 should become rare may have observed spreading out generates its own problems end long line pilots airplane must fly close other transmitters taking off landing can make both adjacentchannel third-order signals strong enough cause glitches critical point flight What might have dip during fly-by becomes serious deviation close ground Now pay attention Owen Blacks Pacific Plan separates 31M pairs 60 ft flight line thereby reducing pos sible intermodulation signal power INSIGNIF ICANT LEVELS has proven need avoid problem Back field testing Bob have spent some time testing small group RC systems using revised procedure results five dif ferent systems tests show some interesting things bad news OWBAM interference always worst particularly considering 20 kHz adjacent-channel interference good news OWBAM interfer ence should start disappear soonas OWBAM transmitters replaced Besides paragraph 314 AMA Frequen cy Use Plan doesnt permit OWBAM trans mitter within 20 kHz another transmitter thats true RIGHT NOW about 1991 go 50 channels will spaced 20 kHz encounter someone local flying field operating OWBAM transmitter RC38-RC56 hasnt upgraded since 1982 THATS test first receivers pass new tests Polks Challenger 720 FM receiver Ace RIC Inc Model 91 AM receiver Polks should congratulated rewarded sales great improvement have made over last years Challenger 620 new Challenger 720 receiver scored bullet proof against three types single adjacentchannel transmitters both 20 40 kHz scored Very Good against FLS 20 40 kHz transmitter meets AMA require ments use channel receiver best weve ever tested amazing part low-priced system Polks Modeleraft Hobbies 346 Bergen Ave Jersey City NJ 07304 telephone 1-800-225-POLK Ace R/C Model 91 AM dual-conver sion receiver scored Very Good against three types single narrow-band adjacentchannel transmitters 20 40 kHz Very Good against FLS 40 kHz Ace R/C Inc Box 51 lE Higginsville MO 64037 tele phone 816 584-7121 What does mean real world think means Aristocraft/High-Tec Chal lenger 720 will work fine RC aircraft channelnow beyond 1991 Ace R/C Model 91 should well against 1988 narrow-band environment will exist RCl2-RC34 YOU make happen narrow-band environment planned 1991 beyond ITS STILL ALL UP TO YOU Water Flying/Westwood Continued page 40 add floatplane modifications will 20% 25% heavier get off water models performance will probably disappointing reason thrust-to-weight ratio just dropped same 20% 25% may pick up bit loss us ing prop lower pitch wing loading too high say 22 oz/sq ft thing going save larger engine rule thumb automatically go next size en gine though Ive seen some models took increase couple engine sizes make difference last optional characteristic Im going discuss wing loading However its op tional youre standing Continued page 140 ELLERS NEW CYCLE S 100 THP DESIGN TAILORED HELICAL PITCH DEVELOPEDTO GIVE MAXIMUM THRUST AT 4 CYCLE ENGINE RPM ALLTHE LATEST TECHNIQUES USED ON OUR PRO SERIES 3 SEE BELOW DIA PITCH THP PRICE 12661477/z8 13677/28 146778 1567 16678 NEW NEW HIGH TECH AIRFOIL SECTION 10T020%INCREASE IN THRUST MFG OF SELECT HARD MAPLE WOOD WILL NOT FATIGUE LIKE SYNTHETICS FUEL PROOF HIGH LUSTER FINISH DIA PITCHPRICE 5S/34 634 72833/456 8334568 845667 f94566/ 77 /2 10 4566/27 6EW 46777I 78 j SEW /267 124W 125W 1266 1356 1456 1556 164N 16678 ii V May1988 101 THE LEADER IN COMPETITION PRO SERIES 3 RC PYLON RACING SERIES 500 DIAPITCHPRICE 7 5N 5/N SERIES 400C 866777 977/7 W WIDE BLADE EW EXTRA WIDE N NARROW IcZ22ZZI Water FIying/Westwood Continued page 101 counter local hobby shop ponder ing what airplane will make best float conversion Most trainer models have wing loadings 18 oz per sq ft Adding floats will raise value about 23 25% crease assuming theres enough pow er pussycat just turned real tiger dont need tiger just yet perhaps will help know right wing load ing start recommend 20 oz per sq ft reason figure corresponds stall speed 20 mph maximum lift coefficient 12 assumed Reynolds numbers 12 about can expect results what call 20/20 machine just average power 20/20 models will jump off water less 100 ft usually around 50 no wind Add little headwind liftoff will right bird comes up step pAN5pAC Impervious Exhaust Products Eliminate Burned Up & Blown Out Silicone 1000/0 SatIsfaction Guaranteed Money Back SEND 450 per 5/B ID Coupler or55aper3/4ID DANA AEROSPACE CORP 1110 E 5th St rior WI 54880 140 Model Aviation MASTER AIRSCREW Back hobby shop look box es behind counter mentally add 25% stated flying weight compute wing loading four prob ably will jump right out Sig Cub Kadet Senior Eagle 63 Telemaster 40 last really comes Hobby Lob might hobby shop too Cub Eagle both need extra 30% vertical fin area other two will float right out box ll almost Hopefully have provided enough good stuff get down water ma chine will fly well enough win fun fly events get hooked float fly ing water site boat youll find whole lot easier land flyingand cleaner too sincere desire help add water flying site inventory ease pressure existing land facili ties Lets go F When responding advertisers mention read about ModelAviation TacticalNNVi HighA IKit Includes II Mach ne Cut ISanded Balsa Ply II Foam Parts Full S ze Rolled Plans Instruct Gu de Necessary Hardware Specifications wingspan 44 Weight 9A bs Power RK-740 ft PO Box 224071 1900 Houston TX shipping 713621-1462 RC Scale/Wischers Continued page 43 tip wood strip end wood strip resting against panel beneath instrument dial image will centered within frame photo roll Just wind film shoot No need look through viewfinder image film will exact scale model exposure After film developed have contact prints made proof prints roll readymade instrument faces favored film Kodak Tri-X system provides prints highest pos sible definition because no enlargement steps process requires camera lens quite close focusing capability can used model scales up including quarter-scale thing remember three-inch dial /3 -scale larger 35mm film frame procedure color prints local processor places camera farther away panel because prints enlarged about 37 times original negative size jumbo prints Continuing example -scale model three-inch-diameter instrument would like diameter print 60 image waxed paper ground glass should 60 -- 37 16-in-diameter exercise math intended arrive dimension will produce proper scale ratio Measure camera-to-subject dis tance image size load camera color film proceed take photos air plane distance using wood strip spacing use steel tape exposure wood strip will show up print always underneath instrument minimize direct reflections glass cov ering instrument face lower camera slightly line sight isnt right angles glass using wood strip helps have painted flat black Wearing dark clothing helps keep photographer Out reflections also take photos stand ing outside cockpit Reflections glass arent really serious since present view instru ment panel anyway Reflections can elimi nated using polarizing filter either black-and-white color systems described lens best adapted wide angle employ 35mm focal length has minimum focusing distance nine inches color process wide angle lens brings camera up close panel seat backs airplane dont interfere foregoing necessary pro ducing instrument faces correct airplane being modeled panel itself can made 062-in styrene sheet holes cut instruments have painting pan els same black crackle spray can 10 years Some instruments have bezel surrounding face Make sliced tubing strips aluminum wrapped around dowel bezel glued hole instrument face photo print glued back panel prints made glossy paper illusion glass face enhance appearance clear plastic sheet can sandwiched between face panel set plastic discs bezels add depth instrument face make Continued page 142 &4ntique Series High Performance Propeller Distinctive Shape new Antique Series features undercambered turbo-style blades distinctive scimitar shape series specially designed 60 120 two four stroke applica tions Made high visibility gold glass-filled nylon modeler looking quality high performance Sizes 12x6 13x6 14x7 16x7 WINDSOR PROPELLER CO 384 Tesconi Court Santa Rosa CA 95401