SI Year Blimp What type RC model has following characteristics 1 flies ultra-slow speeds 2 stable yet responsive maneuverable 3 durable harmless people objects might contact 4 produces little noise pollution 5 operable inexperi enced spectators points became criteria Slow Year Blimp developed merely beginning~ author says potentially sign ifi cant THE CLUB belong has recently faced common problem flying site uncertainty Neigh bors distance lease status have threatened flying field loss continuation club pursuing alternative sites mem bers recognized need some PR Support general public can invaluable seeking use park land other community property creating favorable impression dealings private landowners frequent method obtaining citizen appre ciation modeling demonstrate graphic ally through show team performances static displays shopping malls both help forming good opinion has certain limitations Show team performances often take place before audiences predisposed receptive area suited model flying Mall displays reach deeper broad spectrum public compete antique collectors Scout troops portrait artists myriad other attactions common areas shopping malls Slides movies help can fail capture special something sets building flying models apart other activities Somehow reasoned missing elementlive operationhad introduced otherwise static setting About time list criteria began article being drawn up response need early ads First Indoor RC Contest International Modeler Show 62 Model Aviation Slow Year Blimp cruises overhead Designer/Author Lou Bruhn Checking TV camera crew cabin Lightweight payload possibilities endless RUDDER 0PWR ARE 4 040OP YB INCH NOYR LAYEMFOAM COST OF 001 MYLARALTERNATE SHAPE TO OUTLINE .L-.MATCH APTERPOW00NRUMP 5 L___ --- ___ ____ _ _ ODEMIaL POLO LINE -00 NOT CUT-r POLO PRODUECS S LAYERS OLO LINE -OONOTCUT 5 IPOLD PAROWIC-ES LAYERS CD APPROTI 5 FORWARD OP COUNTER 0 E RIRSREAARR t-4I NZIif USE 0PUCE U-SECTION 5 OW PEWS P05101015 SAITCH IF YOUR SIPITOI IDES SOT RRTCW TESIOSS SIEWNI ULTOR WIRIWO TO 151101 FUNCTIONS GONDOLA BESIWN CAN RB ABSURD 10 SUIT RADIO LAYOUT OR ODORNAROCRI RE-UN/ TASTE IN DOSION RU OR SW CHES OUVIRO Tb-PUCE MOTORS SWLT oLOIJ-'fPUT RI LWENTER UP SWITCH PLATE IDAHORIONRUTUTIRUCESITER IIIIflu QDICYoW-TORN 4 11111SERVO All DRAM CO AR lASER IAdIZ SUNTANSOLDERI AVANTILIIII2L BRASSPROM WNSS 1111 OROTATE GI ON/APP SPEEDLIBSIWAP SERVO-11ffi--jOU BRUHN HEW WOO OVERRIDE YOKE TOTS IPTEIRO FOR SWITCHES ROWING THE TMPOLE TEWIOMLO TN THE SWITCH ETOES AlTO INPUT TO ROTATING CENTER PLATE THROUHI WIPER CONTACTS SLOW YEAR BLIMP appearing magazines addition heavierthan-air classes competition featured lighterthan-air LTA category inspiraton novelty coupled large doubt success fully satisfying preceding criteria conventional heavier-than-air technology led begin investigation LTA Consider ing possibility eventual success added requirement list construction should use non-toxic materials tech niques others might readily duplicate project Initial research showed LTA practic ally unknown model magazine readers aside handful isolated efforts spread over years Nearly involved rigid dirigible frameworks aerodynamic control surfaces soon ruled Out first features being too cumbersome transport time-consuming too easily damaged latter feature involved need constant forward motion complex extensive control linkages An alternative concept non-rigid blimp controlled directed thrust began take shape arrangement prospect exceptional maneuverability includ ing reverse direction turns place nearly vertical ascents descents buoyant lift chose forego slight advantage hydrogen total safety helium have never regretted decision challenge adequately restrict extremely small gas molecules escaping achieve usefully long period between ballast readjust ments way complicated automatic remotely-controlled ballast reduction systems could avoided clear key success LTA vehicle lay method constructing gas containment bag Research indicated instrumented atmospheric research balloons shrinks somewhat heateda feature made laminated layers polyester film would take particular significance later Moresuch DuPonts Mylar Polyester has over polyester mil 001 thick availbest gas retention factors film material t able transparent rolls 40 wide 50 ft long also has exceptional tensile strength less $10 Ichose gauge best com Dawn Hux holds Hula-Hoop blimp show its stuff Tricks like take practice careful control momentum PR possibilities led undertaking March 1981 63 WIRE 5009 OUPPON TAPED TO RORTOM OP RUMP 1100K 011 OORAOOLW 1 0 Note construction sequences shad ed lines representative joining tape 1 Cut piece film double length uninflated blimp Fold film three timesfirst across length twice lengthper layout drawing marker draw cut line along edge opposite final fold Holding layers alignment cut completely through along line Result will two identical double-gore pieces Clean both sides film acetone along future seams Position firstgore piece smooth hard clean surface Start 3M /2-in double-stick tape through notch between gores follow nearer edge curve lapping tape half onto film half onto work surface Roll tape down side pen avoid direct contact fingers Prevent gaps bubbles untaping redoing affected area 2 Carefully matching film edges exactly fold second gore over Onto first Start notch pay film down onto tape eliminating gaps bubbles occur Remove tape work surface along seam Youve done itl Now repeat other three notch seams checking fold will turn same way both ends gore Handle carefully seams dont come undone Result will two blimp halves 3 Lay both blimp halves flat top another untaped edges aligned Around mid-point edge mark longitudinal alignment same place film layers Set blimp half aside Spread untaped edges remaining blimp half apart bulk hanging off edge work surface tape down long seam edge Step 1 Small view shows slicethrough blimpif made now 4 Mate blimp halvestogetheralong just-taped seam making sure nose-to-nose inside-to-inside surface orientaton Start matching together alignment spots edge press film down Step 2 direction lJpperview shows slice stage Now remove surplus tape seam lift whole assembly clear complete remain ing long seam same manner Leave about I-ft tapeless gap arrows straight part final seam Lower right final slice view 6 Prepare apply outer tape seams securely taping clean bowl upside-down near corner table Flatten blimp Out no seam overlaps another Starting notch seam hold blimp down against bowl seam interior flap folded toward point contact bowl Beginning about 1 above notch apply3M #853-in Mylarsingle stick tape overtop seam Overlap both sides equally Dont allow interior flap become smaller larger seam progressively spreading apart pulling together Complete remaining seams same manner except gap 5 Resist urge inflate blimp Turn film Inside out actually right-side-out through tapeless gap seam Work slowly beginning far thest end Careful work pays off promise between strength weight clear transparent because cost minimum order quantities exotic colored metalized laminated versions couldnt justified small project such uncertain outcome material selected problem next forming proper shape size shape traditional blimp con tours seemed like good bet tail surface small hamper control backing up ease basic problem making closed container multiple compound curves flat material planned cut tail fins foam plastic meat trays tape place About easiest way forming generally paraboloid shape end blimp attach tapering gore pieces alongside another closed loop manner parachute technique surface contour would become pleasingly smoother number individual gores increased Clearly though some compromise called between aes thetics spending rest life fastening seams together Impatient see total concept worked settled having four gore pieces stretching nose tail tapered end As turned out ideal high temperature tolerance Mylar makes heat-welding seams critical procedure Addi tionally modelers have access heat-seaming equipment series experiments done perfect alternate method Special contact cement could brushed smoothly uniformly enough Tape looked promising construct compound curvature seams full-size form build over After much trial error pondering later technique described construction sec 64 Model Aviation 7 Fillertube made same material blimp Use pattern form cylinder Part way up base end ring tube Mylartape Below ring cut about eight equal flanges fold outward work surface lay double-sticktape square approx 2-in sides Holding tape circular set down base centered tape square Lay Mylar tape down across flange innermost edge barely covers gap either side near upright tube Trim taped flange area circular outline approx 2-in diameter Lift fillertubewith double-stick tape bottom S1 8 Inflate blimp last through tapeless gap vacuum cleaner hose attached discharge outlet Blimp now resembles rumpled boxy banana Sparingly tape over gap end seams come together Tape small square patch over end Position filler tube mid way between seams point behind lengthwise center blimp Tape down flange covering gaps Point modelers knife tube make X-cut skin inside Tapeless seam gap now can finished oft permanently Reinflate blimp twist filler tube tight secure rubberband Now best part Iron blimp over except tape MonoKote setting Make tail fins cabin attachment rings handling lines etc tape place Glue Velcro pads contact cement Paintailtaped seamswith two coats polyurethane thinned 50% Take vacation reacquaint yourself family friends outside world tion developed overcomes problems involved except onesuccess relates directly amount care patience exerts later next turned attention control system satisfy number criteria provide high degree maneuver ability several axes yet consume little power light weight course should simple rugged reliable directed thrust scheme potentially met requirements addition furnishing propulsion offered nearly direct movement desired direction sharp turning might have possible theoretically just thruster seemed easier positive use located near blimps center-ofgravity way energy would pointlessly wasted pitching rolling vehicle might look dramatic wouldnt effective maneuvering nearly stationary finally opted two thrusters either side cabin suspended beneath center gas containment bag could work col lectively same direction opposite direc tions differentially same direction different speeds both thrusters mounted ends cross tube could rotate about its longitudinal axis could pointed up down changing altitude boiled down three basic functions throttle including forward/reverse capability heading altitude felt possible achieve three control channels As thrusters themselves type quiet flexible enough electric power still left wide range possibilities easiest would have remove gears pair servos use motor/amplifier circuits mount propellers directly pinion shafts motors As Luther Hux subsequently demonstrated arrangement works quite well initially resisted appeal ingly simple solution two reasons conventional transmitter control arrangrnent possible use electronic mixing violating simple-to-duplicate rule skeptical power ungeared servo motors turn propellers adequately An alternative separate propulsion system RC system using latter solely control voltage polarity used former Modifying coreless armature motor appropriate gear reduction ratio proved frustrating repositioned pinion gear could made keep slipping its shaft being able locate other low-cost substitutes gears took chance 3volt Mabuchi RE-14 motors $150 4-in diameter rubber model propellers shoved onto shafts first glance propulsion motor control seemed demand nearly linear rpm change no steps requirement potentiometer series would have served nicely Continued page 120 March 1981 65 iimp caoin sop view snowing front back motor battery pack 100 mAh receiver battery dual multi-position rotary switches pushrod yokes brick-style receiver including elevation throttle servos heading servo Du-Bro mechanical mixer pushrods switches author shown compressing blimp remove airfrom inside maximum lifting ability much airas possible must removed blimp before inflating helium assisting Slights Xerox Training Center Ralph Heath logs some blimp time Lou gives instructions INTRODUCING TIle Arlleri RJL K61 R/C ENGINE RJL Industries now produces renowned engine formerly manufactured Kraft Systems Inc schnuerle ported 61 cubic inch engine provides easy starting high performance longevity Produced finest materials workmanship quality assurance youll proud have aircraft powered K61 FEATURES INCLUDE Schnuerle Ports Boost Port Double Ball Bearings Forged Alloy Piston & Con Rod Bushed Connecting Rod 0- ring Sealed Back Cover 16 HPat 15500 RPM SUGGESTED RETAIL $13995 Muffler Included Send Free Catalog Today R J L INDUSTRIES P0 Box 5654 Pasadena CA 91107 1831 Business Center Dr Duane CA 91010 wreckage ship strike Air Force vehicle parked field ship itself actually struck ground approximately 15 ft front vehicle however due planes high speed resultant wreckage immediately struck vehicle damaging actual hazard contributing factor hazard hazard am writing about cause ship going down planning stage demonstration re quested project officer radio operations 70 80 MHz range shut down demo fact accom plished base personnel However known club local TV stations area would using newer equipment cover event newer equipment being pressed use more TV stations commonly known live action remote TV Basically consists portable TV unit coupled high-powered transmitter make use live-coverage techniques Units transmitting frequencies actually adjacent own flying frequencies lies actual hazard transmit devices power output far exceeds power used own equipment adjacent frequency can bleed over enough point flying opera tions endangered case particular accident Clubs AMA demonstration teams should made aware potentially dangerous hazard soon possible avoid type accident occurring accident extremely close being disastrous aircraft airborne -second ship would have impacted upon car airborne another full second would have impacted upon USAF Thunderbird aircraft ship would have flying another direction loss control occurred could very well have flown crowd people estimated 3000-plus Luckily God willing case potential caution identifying hazard exercised organization giving demonstration result can disastrous mentioned above Sincerely yours s Michael S Lee President Luke Condors RC Club wind up months column item seen November 1980 issue British magazine Radio Control Models & Electronicsgives us food thought New Products RC Hobby section magazine write-up fail-safe device put Out Chromatronics mentioned previous column device neutralizes controls retards throttle either interference transmitter mal function occurs statement caught eye opening sentence mandatory conditions granting permit fly model aircraft excess 5-kg 11 lb weight provision fail-safe system stated mandates use fail-safe devices assume must some branch British government end question should consider using such fail-safe devices biggies show team models voluntary basis John Preston 7012 Elvira Court Falls Church VA 22042 Slow Year Blimp/Bruhn Continued page 65 However need reverse electrical polarity after tapering down power-off condition motor could advance opposite rotation Electronic throttles too costly heavy experiment mechanical arrangement reversing potenti ometer rotation conjunction switching polarity looked very complex Again taking expedient route hoped multiple position rotary switch could work enabled small enough stepped power changes direction pair inexpensive 12-position electronic switches modified provide two-step center off two-step reverse polarity independent control motor Actually moving switches appropriate position combinations required connecting control shafts through mechanical servo mixer blended throttle heading functions fact rotary switches positioned linear push-pull action meant travel limited less 1800 order avoid linkage jamming extremes throw Competing against commercial switch contacts necessitated about 1400 rotation cover full five-position sequence Without some compensation combination hard turn full throttle would drive pushrod other past jam limits avoid sliding pushrod/yoke arrangement added switch shafts Packaging sheet balsa cabin along three-channel radio system 24V 450 mAb drive-battery pack ballast made possibly compact serviceable simplest configuration assembly attached underneath gas bag hook end plus mating Velcro pads keep cabin shifting during thrust changes Modeling clay 120 Model Aviation 213/359-0016 Slope Squire Featured R/C SPORTSMAN SaraCen Featured RCM April 1976 Seville$6100 Featured MODEL AVIATION Apr 7 Winterhawk$57 Featured MODEL AVIATION May Hotrock Featured MODEL AVI Simitar 540 Featured RCM Oct 1978 COMPLETE PLANS WING CORE FIBERGLAS FUSELAGE PLYWOOD WING SHEETING CORE FILM WING SHEETING TAPE comes 14 X 60 yd roll $895 XHINGE$189/Pkg N EW EASY-MOUNT K&B 40 L ~dUIB vvrite 20825/z Roscoe Blvd Canoga Park CA 91306 BILL EVANS RIC AIRCRAFT Phone 213 709-0894 U IN Losing control can night mare wrong response given command can take its toll model nerves wallet Radio South know feel about hobby too avid RC enthusiasts nearly half century combined experience CONiRO modeling radio repair So avoid inflated repair costs undue service time Radio South fast economical inhouse radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control VISA 7 jrn Futaba_ 1925 E Creighton RoadPensacola FL 32504 904/478-6745 CUSTOM TUNED ENGINESGET ORGANIZEDWEVE EXPANDEDI COMPETITION ACCESSORIESHeresaseIof4sInrdyf4eSthahOIdSOOCSCALE DRAWINGSPHOTOS BOOKLETS Special GY 014 X 60 solid lines $295 ppd 4 yeas yon inoonte 0, II nagaZOUS Custom needle valves racing wheels4 MAG FILES $4950U quick fills fuel shut -a ffs & othersSend $495 pins $100 postag handling detailed brochure send 25 cents to0GM INDUSTRIESREPLA-TECI-I PO BOX 388-KiNTERNATIONAL Kustom Kraftsmanship Box 2699 Laguna HillsDOVER NH 03820CATALOGS $20048500 MC 5N818 HWY Calif 92653 Ph 714 830-5162voa 088008 97489 stuck around single landing wheel bottom cabin enabled blimp ballasted neutral buoyancy after inflation complete breathed deeply switched radio Construction Before beginning number things should clearly understood its large surface area very low mass blimp affected slightest air current includ ing too faint pilot sense Heating cooling system outlets convection currents outdoor operation impossible operating conditions unless equip blimp extremely high-thrust capability has kept away some otherwise prime sites enough say wasnt worth doubt test area first small helium balloon long string Second degree greater conventional projects success dependent amount patient attention given repetitious actions Helium escapes pathway offered including right through film material low rate course Seams must near perfect possible rapid loss buoyant gas will drastically shorten length operating time before removal ballast becomes necessary Keep mind youre tempted speed things up little after third seam Time spent being careful well worth later Finally particular design represents first generation stage development instructions precautions followed fairly closely have no doubt will have same level success have will able take real pride accomplishment Con siderable improvement should possible though Probe areas further development suggested end article own thing share rest us Rather give detailed fasten part part B instructions feel would helpful case provide illustrations supplemented notes comments blimps size relates load has support helps start determining weight radio system propulsion system other payload components including ballast Ballast important because will always helium gas leakage temperature/pressure atmospheric changes Some leeway adjust neutral buoyancy essential Dont forget include estimate weight gas bag weighed about 6 oz tail fins weight total ounces approximates ideal displacement cubic feet helium bag sea-level operaton practice some over-sizing must made allow impure gas higher elevation etc cabin pretty conventional once placement components has established Refer drawings photos further guidance Adjustment mechanical mixer linkage switch setup critical aspect assembly Two types switches diagramed Centralab 1002 usable modification isnt readily available modify Radio Shack 12-position shorting type no current interruption changing positions follows 1 Remove position detent ball socket 2 Carefully remove contact deck bottom switch 3 Use file divide inner contact ring two equal unconnected semi-circular segments 4 Remove switch shaft rotating contact disc switch mounting assembly 5 Make cannibalize another switch duplicate metal contact piece like already mounted rotating contact disc 6 Securely fasten new piece onto rotating contact disc would touch bottom deck contacts 1800 original contact piece 7 Adjust contact tension positive free reassemble switch elements Remove metal insert collar electric knob slide fully onto switch shaft tighten set-screw Make brass tin yoke solder onto collar Cut off switch shaft -in above collar Make solder pushrod retainer guide switch mounting washer Wire switch circuit test its operation thoroughly before installing cabin OK its time bite bullet make gas bag Thoroughly clean kitchen table top other very smooth hard Formica-like surface resolve stay until completion might take about week evenings following key points have common goal avoidance leakage paths First apply tape utmost care prevent bubbles gaps Second use smallest number separate pieces tape possible ie long piece rather two shorter pieces Third try avoid handling Mylar roughly folding sharply time Pinhole leaks will likely result Fourth keep clean Tape adheres best surface free grease dust release agent etc Wipe film areas apt taped later acetone before starting assembly Good luck Operation youre satisfied preliminary inflation checks using plain air detach cabin carefully work much air out bag possible Suck through fill tube really collapse flat Install balloon inflation valve onto compressed helium cyl inder prefer lay cylinder its side inflation nipple angled upward Get assis tant take precautions positively retain blimp inflate through fill tube half full cabin can reinstalled Continue inflation until just full overfilling reduces buoyancy increases gas leakage rate stresses seams Squeeze off fill tube near upper end twist lower portion tightly fold over upon itself loop rubberband repeatedly around secure Adjust ballast neutral buoyancy Eureka floats midair Charge batteries fully use Astro Flight 15-mm formula time receiver battery simple Amps X time charge March 1981 121 TLC RIC PRODUCTS Rt 1 Box 282 Prospect VA 23901 thoroughly depleted propulsion battery Opera tion sizes used averages 25 mm Its hard believe genuine excitement novice learning fly blimp confined space like living room Although weightless blimps inertia continues power off whatever direction headed last avoid probably harmless collision lamps plants candles other objects requires frantically reversing control maximum power Finesse called order control momen tum very limited thrust available tually getting hang vertical ascents descents spot landings become routine blimp can flown through hula hoop both backwards forwards calm air degree control seems practically unlimited Larger areas allow relaxed operation heading directional stability over long straight run marginal small tail fins Neverthe less theres always line turn sticks Just watch battery charge blimp small enough transported intact rear compact station wagon back seat folded down Going through rapid temperature changes outdoors indoors can dramatically change skin tension tem porarily Allow some time internal temper ature stabilize before readjusting inflation Future development concept begs modification havent yet time As example gas bag could made high-priced spread colored metalized film real impression seam-making technique should simpler Control system development can take directions electronic mixing geared servo motor thrusters different thruster location biggest opportunity may payloads airborne PA systems signs banners light-bulb changers etc Have ball Just sure pass along Summer Breeze Balloon/Hux Continued page 69 window does first convention filled up balloon nearby room started down hall auditorium entrance double door fixed center bar tightest squeeze yet applied bumper stickers over lock hinges protect balloon sharp edges People began wonder about strange placement campaign material pushed balloon through met several reporters barrage questions candidate came podium let balloon go flew up frontwhere people yet seen Previously described balloon candidate hadnt seen started opening remarks paused staring balloon banner pulled attention back what saying started over again told what expect guess just couldnt believe TV reporter asked us fly during next break film evening saw balloon few seconds announced political news next Imagine surprise have first public flight shown TV first time Lou saw balloon too Some conventions exciting othersnot programs flights buildings heavy air-conditioning equipment balloon pushed around quite lot series air-conditioning vents can play game full up full power under vent opposite between Occasionally someone would try help balloon low enough reach push like might give basketball would help give balloon little altitude would shoot ceiling. full down full power would bounce off ceiling. full up full power would scramble coming down though could hurt anyone settled imagine just sitting minding own business something blew ear type convention flying can cut flight time between recharge about 15 minutes still air could fly long hour lady puzzled transmitter took out hands What asked Its control balloon Im about crash replied calmly knowing balloon harmless After second word crash sank handed back like hot potato after disappeared crowd considered going big convention could just see delegates using big signs play badminton balloon After convention offered Bill Winter chance fly home planned way helium paid already As can read first Just Fun article quite reaciton bull-in-chinashop reaction bit surprise Con sidering room furniture 8-ft ceiling learn guess did seem lot handle could have tried gym Im sure would have enjoyed looks photo article Im sure much fun could thing have remind fliers inertialet off command long before get want go would make excellent training aid astronauts handling control jets weightless equipment Because ofour busy schedules balloon Lous blimp did fly together some time Chuck Thomas made arrangements us fly Saturday morning Xerox Train ing Center provide opportunity Dawn photograph two models pilots together Imagine will Xerox students getting up strolling through mezzanine way get morning cup coffeeand finding hot-air balloon blimp waltzing around building wide-eyed reactions lot fun guy asked unsure voice time go get cameraas thought wouldnt took eyes off thanks Ralph Heath escorting us four-hour photo session plans tell story building balloon problem some will 1 22 Model Aviation Fast realistic aerobatic kit features ABS wheelpants moulded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/03
Page Numbers: 62, 63, 64, 65, 120, 121, 122
SI Year Blimp What type RC model has following characteristics 1 flies ultra-slow speeds 2 stable yet responsive maneuverable 3 durable harmless people objects might contact 4 produces little noise pollution 5 operable inexperi enced spectators points became criteria Slow Year Blimp developed merely beginning~ author says potentially sign ifi cant THE CLUB belong has recently faced common problem flying site uncertainty Neigh bors distance lease status have threatened flying field loss continuation club pursuing alternative sites mem bers recognized need some PR Support general public can invaluable seeking use park land other community property creating favorable impression dealings private landowners frequent method obtaining citizen appre ciation modeling demonstrate graphic ally through show team performances static displays shopping malls both help forming good opinion has certain limitations Show team performances often take place before audiences predisposed receptive area suited model flying Mall displays reach deeper broad spectrum public compete antique collectors Scout troops portrait artists myriad other attactions common areas shopping malls Slides movies help can fail capture special something sets building flying models apart other activities Somehow reasoned missing elementlive operationhad introduced otherwise static setting About time list criteria began article being drawn up response need early ads First Indoor RC Contest International Modeler Show 62 Model Aviation Slow Year Blimp cruises overhead Designer/Author Lou Bruhn Checking TV camera crew cabin Lightweight payload possibilities endless RUDDER 0PWR ARE 4 040OP YB INCH NOYR LAYEMFOAM COST OF 001 MYLARALTERNATE SHAPE TO OUTLINE .L-.MATCH APTERPOW00NRUMP 5 L___ --- ___ ____ _ _ ODEMIaL POLO LINE -00 NOT CUT-r POLO PRODUECS S LAYERS OLO LINE -OONOTCUT 5 IPOLD PAROWIC-ES LAYERS CD APPROTI 5 FORWARD OP COUNTER 0 E RIRSREAARR t-4I NZIif USE 0PUCE U-SECTION 5 OW PEWS P05101015 SAITCH IF YOUR SIPITOI IDES SOT RRTCW TESIOSS SIEWNI ULTOR WIRIWO TO 151101 FUNCTIONS GONDOLA BESIWN CAN RB ABSURD 10 SUIT RADIO LAYOUT OR ODORNAROCRI RE-UN/ TASTE IN DOSION RU OR SW CHES OUVIRO Tb-PUCE MOTORS SWLT oLOIJ-'fPUT RI LWENTER UP SWITCH PLATE IDAHORIONRUTUTIRUCESITER IIIIflu QDICYoW-TORN 4 11111SERVO All DRAM CO AR lASER IAdIZ SUNTANSOLDERI AVANTILIIII2L BRASSPROM WNSS 1111 OROTATE GI ON/APP SPEEDLIBSIWAP SERVO-11ffi--jOU BRUHN HEW WOO OVERRIDE YOKE TOTS IPTEIRO FOR SWITCHES ROWING THE TMPOLE TEWIOMLO TN THE SWITCH ETOES AlTO INPUT TO ROTATING CENTER PLATE THROUHI WIPER CONTACTS SLOW YEAR BLIMP appearing magazines addition heavierthan-air classes competition featured lighterthan-air LTA category inspiraton novelty coupled large doubt success fully satisfying preceding criteria conventional heavier-than-air technology led begin investigation LTA Consider ing possibility eventual success added requirement list construction should use non-toxic materials tech niques others might readily duplicate project Initial research showed LTA practic ally unknown model magazine readers aside handful isolated efforts spread over years Nearly involved rigid dirigible frameworks aerodynamic control surfaces soon ruled Out first features being too cumbersome transport time-consuming too easily damaged latter feature involved need constant forward motion complex extensive control linkages An alternative concept non-rigid blimp controlled directed thrust began take shape arrangement prospect exceptional maneuverability includ ing reverse direction turns place nearly vertical ascents descents buoyant lift chose forego slight advantage hydrogen total safety helium have never regretted decision challenge adequately restrict extremely small gas molecules escaping achieve usefully long period between ballast readjust ments way complicated automatic remotely-controlled ballast reduction systems could avoided clear key success LTA vehicle lay method constructing gas containment bag Research indicated instrumented atmospheric research balloons shrinks somewhat heateda feature made laminated layers polyester film would take particular significance later Moresuch DuPonts Mylar Polyester has over polyester mil 001 thick availbest gas retention factors film material t able transparent rolls 40 wide 50 ft long also has exceptional tensile strength less $10 Ichose gauge best com Dawn Hux holds Hula-Hoop blimp show its stuff Tricks like take practice careful control momentum PR possibilities led undertaking March 1981 63 WIRE 5009 OUPPON TAPED TO RORTOM OP RUMP 1100K 011 OORAOOLW 1 0 Note construction sequences shad ed lines representative joining tape 1 Cut piece film double length uninflated blimp Fold film three timesfirst across length twice lengthper layout drawing marker draw cut line along edge opposite final fold Holding layers alignment cut completely through along line Result will two identical double-gore pieces Clean both sides film acetone along future seams Position firstgore piece smooth hard clean surface Start 3M /2-in double-stick tape through notch between gores follow nearer edge curve lapping tape half onto film half onto work surface Roll tape down side pen avoid direct contact fingers Prevent gaps bubbles untaping redoing affected area 2 Carefully matching film edges exactly fold second gore over Onto first Start notch pay film down onto tape eliminating gaps bubbles occur Remove tape work surface along seam Youve done itl Now repeat other three notch seams checking fold will turn same way both ends gore Handle carefully seams dont come undone Result will two blimp halves 3 Lay both blimp halves flat top another untaped edges aligned Around mid-point edge mark longitudinal alignment same place film layers Set blimp half aside Spread untaped edges remaining blimp half apart bulk hanging off edge work surface tape down long seam edge Step 1 Small view shows slicethrough blimpif made now 4 Mate blimp halvestogetheralong just-taped seam making sure nose-to-nose inside-to-inside surface orientaton Start matching together alignment spots edge press film down Step 2 direction lJpperview shows slice stage Now remove surplus tape seam lift whole assembly clear complete remain ing long seam same manner Leave about I-ft tapeless gap arrows straight part final seam Lower right final slice view 6 Prepare apply outer tape seams securely taping clean bowl upside-down near corner table Flatten blimp Out no seam overlaps another Starting notch seam hold blimp down against bowl seam interior flap folded toward point contact bowl Beginning about 1 above notch apply3M #853-in Mylarsingle stick tape overtop seam Overlap both sides equally Dont allow interior flap become smaller larger seam progressively spreading apart pulling together Complete remaining seams same manner except gap 5 Resist urge inflate blimp Turn film Inside out actually right-side-out through tapeless gap seam Work slowly beginning far thest end Careful work pays off promise between strength weight clear transparent because cost minimum order quantities exotic colored metalized laminated versions couldnt justified small project such uncertain outcome material selected problem next forming proper shape size shape traditional blimp con tours seemed like good bet tail surface small hamper control backing up ease basic problem making closed container multiple compound curves flat material planned cut tail fins foam plastic meat trays tape place About easiest way forming generally paraboloid shape end blimp attach tapering gore pieces alongside another closed loop manner parachute technique surface contour would become pleasingly smoother number individual gores increased Clearly though some compromise called between aes thetics spending rest life fastening seams together Impatient see total concept worked settled having four gore pieces stretching nose tail tapered end As turned out ideal high temperature tolerance Mylar makes heat-welding seams critical procedure Addi tionally modelers have access heat-seaming equipment series experiments done perfect alternate method Special contact cement could brushed smoothly uniformly enough Tape looked promising construct compound curvature seams full-size form build over After much trial error pondering later technique described construction sec 64 Model Aviation 7 Fillertube made same material blimp Use pattern form cylinder Part way up base end ring tube Mylartape Below ring cut about eight equal flanges fold outward work surface lay double-sticktape square approx 2-in sides Holding tape circular set down base centered tape square Lay Mylar tape down across flange innermost edge barely covers gap either side near upright tube Trim taped flange area circular outline approx 2-in diameter Lift fillertubewith double-stick tape bottom S1 8 Inflate blimp last through tapeless gap vacuum cleaner hose attached discharge outlet Blimp now resembles rumpled boxy banana Sparingly tape over gap end seams come together Tape small square patch over end Position filler tube mid way between seams point behind lengthwise center blimp Tape down flange covering gaps Point modelers knife tube make X-cut skin inside Tapeless seam gap now can finished oft permanently Reinflate blimp twist filler tube tight secure rubberband Now best part Iron blimp over except tape MonoKote setting Make tail fins cabin attachment rings handling lines etc tape place Glue Velcro pads contact cement Paintailtaped seamswith two coats polyurethane thinned 50% Take vacation reacquaint yourself family friends outside world tion developed overcomes problems involved except onesuccess relates directly amount care patience exerts later next turned attention control system satisfy number criteria provide high degree maneuver ability several axes yet consume little power light weight course should simple rugged reliable directed thrust scheme potentially met requirements addition furnishing propulsion offered nearly direct movement desired direction sharp turning might have possible theoretically just thruster seemed easier positive use located near blimps center-ofgravity way energy would pointlessly wasted pitching rolling vehicle might look dramatic wouldnt effective maneuvering nearly stationary finally opted two thrusters either side cabin suspended beneath center gas containment bag could work col lectively same direction opposite direc tions differentially same direction different speeds both thrusters mounted ends cross tube could rotate about its longitudinal axis could pointed up down changing altitude boiled down three basic functions throttle including forward/reverse capability heading altitude felt possible achieve three control channels As thrusters themselves type quiet flexible enough electric power still left wide range possibilities easiest would have remove gears pair servos use motor/amplifier circuits mount propellers directly pinion shafts motors As Luther Hux subsequently demonstrated arrangement works quite well initially resisted appeal ingly simple solution two reasons conventional transmitter control arrangrnent possible use electronic mixing violating simple-to-duplicate rule skeptical power ungeared servo motors turn propellers adequately An alternative separate propulsion system RC system using latter solely control voltage polarity used former Modifying coreless armature motor appropriate gear reduction ratio proved frustrating repositioned pinion gear could made keep slipping its shaft being able locate other low-cost substitutes gears took chance 3volt Mabuchi RE-14 motors $150 4-in diameter rubber model propellers shoved onto shafts first glance propulsion motor control seemed demand nearly linear rpm change no steps requirement potentiometer series would have served nicely Continued page 120 March 1981 65 iimp caoin sop view snowing front back motor battery pack 100 mAh receiver battery dual multi-position rotary switches pushrod yokes brick-style receiver including elevation throttle servos heading servo Du-Bro mechanical mixer pushrods switches author shown compressing blimp remove airfrom inside maximum lifting ability much airas possible must removed blimp before inflating helium assisting Slights Xerox Training Center Ralph Heath logs some blimp time Lou gives instructions INTRODUCING TIle Arlleri RJL K61 R/C ENGINE RJL Industries now produces renowned engine formerly manufactured Kraft Systems Inc schnuerle ported 61 cubic inch engine provides easy starting high performance longevity Produced finest materials workmanship quality assurance youll proud have aircraft powered K61 FEATURES INCLUDE Schnuerle Ports Boost Port Double Ball Bearings Forged Alloy Piston & Con Rod Bushed Connecting Rod 0- ring Sealed Back Cover 16 HPat 15500 RPM SUGGESTED RETAIL $13995 Muffler Included Send Free Catalog Today R J L INDUSTRIES P0 Box 5654 Pasadena CA 91107 1831 Business Center Dr Duane CA 91010 wreckage ship strike Air Force vehicle parked field ship itself actually struck ground approximately 15 ft front vehicle however due planes high speed resultant wreckage immediately struck vehicle damaging actual hazard contributing factor hazard hazard am writing about cause ship going down planning stage demonstration re quested project officer radio operations 70 80 MHz range shut down demo fact accom plished base personnel However known club local TV stations area would using newer equipment cover event newer equipment being pressed use more TV stations commonly known live action remote TV Basically consists portable TV unit coupled high-powered transmitter make use live-coverage techniques Units transmitting frequencies actually adjacent own flying frequencies lies actual hazard transmit devices power output far exceeds power used own equipment adjacent frequency can bleed over enough point flying opera tions endangered case particular accident Clubs AMA demonstration teams should made aware potentially dangerous hazard soon possible avoid type accident occurring accident extremely close being disastrous aircraft airborne -second ship would have impacted upon car airborne another full second would have impacted upon USAF Thunderbird aircraft ship would have flying another direction loss control occurred could very well have flown crowd people estimated 3000-plus Luckily God willing case potential caution identifying hazard exercised organization giving demonstration result can disastrous mentioned above Sincerely yours s Michael S Lee President Luke Condors RC Club wind up months column item seen November 1980 issue British magazine Radio Control Models & Electronicsgives us food thought New Products RC Hobby section magazine write-up fail-safe device put Out Chromatronics mentioned previous column device neutralizes controls retards throttle either interference transmitter mal function occurs statement caught eye opening sentence mandatory conditions granting permit fly model aircraft excess 5-kg 11 lb weight provision fail-safe system stated mandates use fail-safe devices assume must some branch British government end question should consider using such fail-safe devices biggies show team models voluntary basis John Preston 7012 Elvira Court Falls Church VA 22042 Slow Year Blimp/Bruhn Continued page 65 However need reverse electrical polarity after tapering down power-off condition motor could advance opposite rotation Electronic throttles too costly heavy experiment mechanical arrangement reversing potenti ometer rotation conjunction switching polarity looked very complex Again taking expedient route hoped multiple position rotary switch could work enabled small enough stepped power changes direction pair inexpensive 12-position electronic switches modified provide two-step center off two-step reverse polarity independent control motor Actually moving switches appropriate position combinations required connecting control shafts through mechanical servo mixer blended throttle heading functions fact rotary switches positioned linear push-pull action meant travel limited less 1800 order avoid linkage jamming extremes throw Competing against commercial switch contacts necessitated about 1400 rotation cover full five-position sequence Without some compensation combination hard turn full throttle would drive pushrod other past jam limits avoid sliding pushrod/yoke arrangement added switch shafts Packaging sheet balsa cabin along three-channel radio system 24V 450 mAb drive-battery pack ballast made possibly compact serviceable simplest configuration assembly attached underneath gas bag hook end plus mating Velcro pads keep cabin shifting during thrust changes Modeling clay 120 Model Aviation 213/359-0016 Slope Squire Featured R/C SPORTSMAN SaraCen Featured RCM April 1976 Seville$6100 Featured MODEL AVIATION Apr 7 Winterhawk$57 Featured MODEL AVIATION May Hotrock Featured MODEL AVI Simitar 540 Featured RCM Oct 1978 COMPLETE PLANS WING CORE FIBERGLAS FUSELAGE PLYWOOD WING SHEETING CORE FILM WING SHEETING TAPE comes 14 X 60 yd roll $895 XHINGE$189/Pkg N EW EASY-MOUNT K&B 40 L ~dUIB vvrite 20825/z Roscoe Blvd Canoga Park CA 91306 BILL EVANS RIC AIRCRAFT Phone 213 709-0894 U IN Losing control can night mare wrong response given command can take its toll model nerves wallet Radio South know feel about hobby too avid RC enthusiasts nearly half century combined experience CONiRO modeling radio repair So avoid inflated repair costs undue service time Radio South fast economical inhouse radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control VISA 7 jrn Futaba_ 1925 E Creighton RoadPensacola FL 32504 904/478-6745 CUSTOM TUNED ENGINESGET ORGANIZEDWEVE EXPANDEDI COMPETITION ACCESSORIESHeresaseIof4sInrdyf4eSthahOIdSOOCSCALE DRAWINGSPHOTOS BOOKLETS Special GY 014 X 60 solid lines $295 ppd 4 yeas yon inoonte 0, II nagaZOUS Custom needle valves racing wheels4 MAG FILES $4950U quick fills fuel shut -a ffs & othersSend $495 pins $100 postag handling detailed brochure send 25 cents to0GM INDUSTRIESREPLA-TECI-I PO BOX 388-KiNTERNATIONAL Kustom Kraftsmanship Box 2699 Laguna HillsDOVER NH 03820CATALOGS $20048500 MC 5N818 HWY Calif 92653 Ph 714 830-5162voa 088008 97489 stuck around single landing wheel bottom cabin enabled blimp ballasted neutral buoyancy after inflation complete breathed deeply switched radio Construction Before beginning number things should clearly understood its large surface area very low mass blimp affected slightest air current includ ing too faint pilot sense Heating cooling system outlets convection currents outdoor operation impossible operating conditions unless equip blimp extremely high-thrust capability has kept away some otherwise prime sites enough say wasnt worth doubt test area first small helium balloon long string Second degree greater conventional projects success dependent amount patient attention given repetitious actions Helium escapes pathway offered including right through film material low rate course Seams must near perfect possible rapid loss buoyant gas will drastically shorten length operating time before removal ballast becomes necessary Keep mind youre tempted speed things up little after third seam Time spent being careful well worth later Finally particular design represents first generation stage development instructions precautions followed fairly closely have no doubt will have same level success have will able take real pride accomplishment Con siderable improvement should possible though Probe areas further development suggested end article own thing share rest us Rather give detailed fasten part part B instructions feel would helpful case provide illustrations supplemented notes comments blimps size relates load has support helps start determining weight radio system propulsion system other payload components including ballast Ballast important because will always helium gas leakage temperature/pressure atmospheric changes Some leeway adjust neutral buoyancy essential Dont forget include estimate weight gas bag weighed about 6 oz tail fins weight total ounces approximates ideal displacement cubic feet helium bag sea-level operaton practice some over-sizing must made allow impure gas higher elevation etc cabin pretty conventional once placement components has established Refer drawings photos further guidance Adjustment mechanical mixer linkage switch setup critical aspect assembly Two types switches diagramed Centralab 1002 usable modification isnt readily available modify Radio Shack 12-position shorting type no current interruption changing positions follows 1 Remove position detent ball socket 2 Carefully remove contact deck bottom switch 3 Use file divide inner contact ring two equal unconnected semi-circular segments 4 Remove switch shaft rotating contact disc switch mounting assembly 5 Make cannibalize another switch duplicate metal contact piece like already mounted rotating contact disc 6 Securely fasten new piece onto rotating contact disc would touch bottom deck contacts 1800 original contact piece 7 Adjust contact tension positive free reassemble switch elements Remove metal insert collar electric knob slide fully onto switch shaft tighten set-screw Make brass tin yoke solder onto collar Cut off switch shaft -in above collar Make solder pushrod retainer guide switch mounting washer Wire switch circuit test its operation thoroughly before installing cabin OK its time bite bullet make gas bag Thoroughly clean kitchen table top other very smooth hard Formica-like surface resolve stay until completion might take about week evenings following key points have common goal avoidance leakage paths First apply tape utmost care prevent bubbles gaps Second use smallest number separate pieces tape possible ie long piece rather two shorter pieces Third try avoid handling Mylar roughly folding sharply time Pinhole leaks will likely result Fourth keep clean Tape adheres best surface free grease dust release agent etc Wipe film areas apt taped later acetone before starting assembly Good luck Operation youre satisfied preliminary inflation checks using plain air detach cabin carefully work much air out bag possible Suck through fill tube really collapse flat Install balloon inflation valve onto compressed helium cyl inder prefer lay cylinder its side inflation nipple angled upward Get assis tant take precautions positively retain blimp inflate through fill tube half full cabin can reinstalled Continue inflation until just full overfilling reduces buoyancy increases gas leakage rate stresses seams Squeeze off fill tube near upper end twist lower portion tightly fold over upon itself loop rubberband repeatedly around secure Adjust ballast neutral buoyancy Eureka floats midair Charge batteries fully use Astro Flight 15-mm formula time receiver battery simple Amps X time charge March 1981 121 TLC RIC PRODUCTS Rt 1 Box 282 Prospect VA 23901 thoroughly depleted propulsion battery Opera tion sizes used averages 25 mm Its hard believe genuine excitement novice learning fly blimp confined space like living room Although weightless blimps inertia continues power off whatever direction headed last avoid probably harmless collision lamps plants candles other objects requires frantically reversing control maximum power Finesse called order control momen tum very limited thrust available tually getting hang vertical ascents descents spot landings become routine blimp can flown through hula hoop both backwards forwards calm air degree control seems practically unlimited Larger areas allow relaxed operation heading directional stability over long straight run marginal small tail fins Neverthe less theres always line turn sticks Just watch battery charge blimp small enough transported intact rear compact station wagon back seat folded down Going through rapid temperature changes outdoors indoors can dramatically change skin tension tem porarily Allow some time internal temper ature stabilize before readjusting inflation Future development concept begs modification havent yet time As example gas bag could made high-priced spread colored metalized film real impression seam-making technique should simpler Control system development can take directions electronic mixing geared servo motor thrusters different thruster location biggest opportunity may payloads airborne PA systems signs banners light-bulb changers etc Have ball Just sure pass along Summer Breeze Balloon/Hux Continued page 69 window does first convention filled up balloon nearby room started down hall auditorium entrance double door fixed center bar tightest squeeze yet applied bumper stickers over lock hinges protect balloon sharp edges People began wonder about strange placement campaign material pushed balloon through met several reporters barrage questions candidate came podium let balloon go flew up frontwhere people yet seen Previously described balloon candidate hadnt seen started opening remarks paused staring balloon banner pulled attention back what saying started over again told what expect guess just couldnt believe TV reporter asked us fly during next break film evening saw balloon few seconds announced political news next Imagine surprise have first public flight shown TV first time Lou saw balloon too Some conventions exciting othersnot programs flights buildings heavy air-conditioning equipment balloon pushed around quite lot series air-conditioning vents can play game full up full power under vent opposite between Occasionally someone would try help balloon low enough reach push like might give basketball would help give balloon little altitude would shoot ceiling. full down full power would bounce off ceiling. full up full power would scramble coming down though could hurt anyone settled imagine just sitting minding own business something blew ear type convention flying can cut flight time between recharge about 15 minutes still air could fly long hour lady puzzled transmitter took out hands What asked Its control balloon Im about crash replied calmly knowing balloon harmless After second word crash sank handed back like hot potato after disappeared crowd considered going big convention could just see delegates using big signs play badminton balloon After convention offered Bill Winter chance fly home planned way helium paid already As can read first Just Fun article quite reaciton bull-in-chinashop reaction bit surprise Con sidering room furniture 8-ft ceiling learn guess did seem lot handle could have tried gym Im sure would have enjoyed looks photo article Im sure much fun could thing have remind fliers inertialet off command long before get want go would make excellent training aid astronauts handling control jets weightless equipment Because ofour busy schedules balloon Lous blimp did fly together some time Chuck Thomas made arrangements us fly Saturday morning Xerox Train ing Center provide opportunity Dawn photograph two models pilots together Imagine will Xerox students getting up strolling through mezzanine way get morning cup coffeeand finding hot-air balloon blimp waltzing around building wide-eyed reactions lot fun guy asked unsure voice time go get cameraas thought wouldnt took eyes off thanks Ralph Heath escorting us four-hour photo session plans tell story building balloon problem some will 1 22 Model Aviation Fast realistic aerobatic kit features ABS wheelpants moulded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/03
Page Numbers: 62, 63, 64, 65, 120, 121, 122
SI Year Blimp What type RC model has following characteristics 1 flies ultra-slow speeds 2 stable yet responsive maneuverable 3 durable harmless people objects might contact 4 produces little noise pollution 5 operable inexperi enced spectators points became criteria Slow Year Blimp developed merely beginning~ author says potentially sign ifi cant THE CLUB belong has recently faced common problem flying site uncertainty Neigh bors distance lease status have threatened flying field loss continuation club pursuing alternative sites mem bers recognized need some PR Support general public can invaluable seeking use park land other community property creating favorable impression dealings private landowners frequent method obtaining citizen appre ciation modeling demonstrate graphic ally through show team performances static displays shopping malls both help forming good opinion has certain limitations Show team performances often take place before audiences predisposed receptive area suited model flying Mall displays reach deeper broad spectrum public compete antique collectors Scout troops portrait artists myriad other attactions common areas shopping malls Slides movies help can fail capture special something sets building flying models apart other activities Somehow reasoned missing elementlive operationhad introduced otherwise static setting About time list criteria began article being drawn up response need early ads First Indoor RC Contest International Modeler Show 62 Model Aviation Slow Year Blimp cruises overhead Designer/Author Lou Bruhn Checking TV camera crew cabin Lightweight payload possibilities endless RUDDER 0PWR ARE 4 040OP YB INCH NOYR LAYEMFOAM COST OF 001 MYLARALTERNATE SHAPE TO OUTLINE .L-.MATCH APTERPOW00NRUMP 5 L___ --- ___ ____ _ _ ODEMIaL POLO LINE -00 NOT CUT-r POLO PRODUECS S LAYERS OLO LINE -OONOTCUT 5 IPOLD PAROWIC-ES LAYERS CD APPROTI 5 FORWARD OP COUNTER 0 E RIRSREAARR t-4I NZIif USE 0PUCE U-SECTION 5 OW PEWS P05101015 SAITCH IF YOUR SIPITOI IDES SOT RRTCW TESIOSS SIEWNI ULTOR WIRIWO TO 151101 FUNCTIONS GONDOLA BESIWN CAN RB ABSURD 10 SUIT RADIO LAYOUT OR ODORNAROCRI RE-UN/ TASTE IN DOSION RU OR SW CHES OUVIRO Tb-PUCE MOTORS SWLT oLOIJ-'fPUT RI LWENTER UP SWITCH PLATE IDAHORIONRUTUTIRUCESITER IIIIflu QDICYoW-TORN 4 11111SERVO All DRAM CO AR lASER IAdIZ SUNTANSOLDERI AVANTILIIII2L BRASSPROM WNSS 1111 OROTATE GI ON/APP SPEEDLIBSIWAP SERVO-11ffi--jOU BRUHN HEW WOO OVERRIDE YOKE TOTS IPTEIRO FOR SWITCHES ROWING THE TMPOLE TEWIOMLO TN THE SWITCH ETOES AlTO INPUT TO ROTATING CENTER PLATE THROUHI WIPER CONTACTS SLOW YEAR BLIMP appearing magazines addition heavierthan-air classes competition featured lighterthan-air LTA category inspiraton novelty coupled large doubt success fully satisfying preceding criteria conventional heavier-than-air technology led begin investigation LTA Consider ing possibility eventual success added requirement list construction should use non-toxic materials tech niques others might readily duplicate project Initial research showed LTA practic ally unknown model magazine readers aside handful isolated efforts spread over years Nearly involved rigid dirigible frameworks aerodynamic control surfaces soon ruled Out first features being too cumbersome transport time-consuming too easily damaged latter feature involved need constant forward motion complex extensive control linkages An alternative concept non-rigid blimp controlled directed thrust began take shape arrangement prospect exceptional maneuverability includ ing reverse direction turns place nearly vertical ascents descents buoyant lift chose forego slight advantage hydrogen total safety helium have never regretted decision challenge adequately restrict extremely small gas molecules escaping achieve usefully long period between ballast readjust ments way complicated automatic remotely-controlled ballast reduction systems could avoided clear key success LTA vehicle lay method constructing gas containment bag Research indicated instrumented atmospheric research balloons shrinks somewhat heateda feature made laminated layers polyester film would take particular significance later Moresuch DuPonts Mylar Polyester has over polyester mil 001 thick availbest gas retention factors film material t able transparent rolls 40 wide 50 ft long also has exceptional tensile strength less $10 Ichose gauge best com Dawn Hux holds Hula-Hoop blimp show its stuff Tricks like take practice careful control momentum PR possibilities led undertaking March 1981 63 WIRE 5009 OUPPON TAPED TO RORTOM OP RUMP 1100K 011 OORAOOLW 1 0 Note construction sequences shad ed lines representative joining tape 1 Cut piece film double length uninflated blimp Fold film three timesfirst across length twice lengthper layout drawing marker draw cut line along edge opposite final fold Holding layers alignment cut completely through along line Result will two identical double-gore pieces Clean both sides film acetone along future seams Position firstgore piece smooth hard clean surface Start 3M /2-in double-stick tape through notch between gores follow nearer edge curve lapping tape half onto film half onto work surface Roll tape down side pen avoid direct contact fingers Prevent gaps bubbles untaping redoing affected area 2 Carefully matching film edges exactly fold second gore over Onto first Start notch pay film down onto tape eliminating gaps bubbles occur Remove tape work surface along seam Youve done itl Now repeat other three notch seams checking fold will turn same way both ends gore Handle carefully seams dont come undone Result will two blimp halves 3 Lay both blimp halves flat top another untaped edges aligned Around mid-point edge mark longitudinal alignment same place film layers Set blimp half aside Spread untaped edges remaining blimp half apart bulk hanging off edge work surface tape down long seam edge Step 1 Small view shows slicethrough blimpif made now 4 Mate blimp halvestogetheralong just-taped seam making sure nose-to-nose inside-to-inside surface orientaton Start matching together alignment spots edge press film down Step 2 direction lJpperview shows slice stage Now remove surplus tape seam lift whole assembly clear complete remain ing long seam same manner Leave about I-ft tapeless gap arrows straight part final seam Lower right final slice view 6 Prepare apply outer tape seams securely taping clean bowl upside-down near corner table Flatten blimp Out no seam overlaps another Starting notch seam hold blimp down against bowl seam interior flap folded toward point contact bowl Beginning about 1 above notch apply3M #853-in Mylarsingle stick tape overtop seam Overlap both sides equally Dont allow interior flap become smaller larger seam progressively spreading apart pulling together Complete remaining seams same manner except gap 5 Resist urge inflate blimp Turn film Inside out actually right-side-out through tapeless gap seam Work slowly beginning far thest end Careful work pays off promise between strength weight clear transparent because cost minimum order quantities exotic colored metalized laminated versions couldnt justified small project such uncertain outcome material selected problem next forming proper shape size shape traditional blimp con tours seemed like good bet tail surface small hamper control backing up ease basic problem making closed container multiple compound curves flat material planned cut tail fins foam plastic meat trays tape place About easiest way forming generally paraboloid shape end blimp attach tapering gore pieces alongside another closed loop manner parachute technique surface contour would become pleasingly smoother number individual gores increased Clearly though some compromise called between aes thetics spending rest life fastening seams together Impatient see total concept worked settled having four gore pieces stretching nose tail tapered end As turned out ideal high temperature tolerance Mylar makes heat-welding seams critical procedure Addi tionally modelers have access heat-seaming equipment series experiments done perfect alternate method Special contact cement could brushed smoothly uniformly enough Tape looked promising construct compound curvature seams full-size form build over After much trial error pondering later technique described construction sec 64 Model Aviation 7 Fillertube made same material blimp Use pattern form cylinder Part way up base end ring tube Mylartape Below ring cut about eight equal flanges fold outward work surface lay double-sticktape square approx 2-in sides Holding tape circular set down base centered tape square Lay Mylar tape down across flange innermost edge barely covers gap either side near upright tube Trim taped flange area circular outline approx 2-in diameter Lift fillertubewith double-stick tape bottom S1 8 Inflate blimp last through tapeless gap vacuum cleaner hose attached discharge outlet Blimp now resembles rumpled boxy banana Sparingly tape over gap end seams come together Tape small square patch over end Position filler tube mid way between seams point behind lengthwise center blimp Tape down flange covering gaps Point modelers knife tube make X-cut skin inside Tapeless seam gap now can finished oft permanently Reinflate blimp twist filler tube tight secure rubberband Now best part Iron blimp over except tape MonoKote setting Make tail fins cabin attachment rings handling lines etc tape place Glue Velcro pads contact cement Paintailtaped seamswith two coats polyurethane thinned 50% Take vacation reacquaint yourself family friends outside world tion developed overcomes problems involved except onesuccess relates directly amount care patience exerts later next turned attention control system satisfy number criteria provide high degree maneuver ability several axes yet consume little power light weight course should simple rugged reliable directed thrust scheme potentially met requirements addition furnishing propulsion offered nearly direct movement desired direction sharp turning might have possible theoretically just thruster seemed easier positive use located near blimps center-ofgravity way energy would pointlessly wasted pitching rolling vehicle might look dramatic wouldnt effective maneuvering nearly stationary finally opted two thrusters either side cabin suspended beneath center gas containment bag could work col lectively same direction opposite direc tions differentially same direction different speeds both thrusters mounted ends cross tube could rotate about its longitudinal axis could pointed up down changing altitude boiled down three basic functions throttle including forward/reverse capability heading altitude felt possible achieve three control channels As thrusters themselves type quiet flexible enough electric power still left wide range possibilities easiest would have remove gears pair servos use motor/amplifier circuits mount propellers directly pinion shafts motors As Luther Hux subsequently demonstrated arrangement works quite well initially resisted appeal ingly simple solution two reasons conventional transmitter control arrangrnent possible use electronic mixing violating simple-to-duplicate rule skeptical power ungeared servo motors turn propellers adequately An alternative separate propulsion system RC system using latter solely control voltage polarity used former Modifying coreless armature motor appropriate gear reduction ratio proved frustrating repositioned pinion gear could made keep slipping its shaft being able locate other low-cost substitutes gears took chance 3volt Mabuchi RE-14 motors $150 4-in diameter rubber model propellers shoved onto shafts first glance propulsion motor control seemed demand nearly linear rpm change no steps requirement potentiometer series would have served nicely Continued page 120 March 1981 65 iimp caoin sop view snowing front back motor battery pack 100 mAh receiver battery dual multi-position rotary switches pushrod yokes brick-style receiver including elevation throttle servos heading servo Du-Bro mechanical mixer pushrods switches author shown compressing blimp remove airfrom inside maximum lifting ability much airas possible must removed blimp before inflating helium assisting Slights Xerox Training Center Ralph Heath logs some blimp time Lou gives instructions INTRODUCING TIle Arlleri RJL K61 R/C ENGINE RJL Industries now produces renowned engine formerly manufactured Kraft Systems Inc schnuerle ported 61 cubic inch engine provides easy starting high performance longevity Produced finest materials workmanship quality assurance youll proud have aircraft powered K61 FEATURES INCLUDE Schnuerle Ports Boost Port Double Ball Bearings Forged Alloy Piston & Con Rod Bushed Connecting Rod 0- ring Sealed Back Cover 16 HPat 15500 RPM SUGGESTED RETAIL $13995 Muffler Included Send Free Catalog Today R J L INDUSTRIES P0 Box 5654 Pasadena CA 91107 1831 Business Center Dr Duane CA 91010 wreckage ship strike Air Force vehicle parked field ship itself actually struck ground approximately 15 ft front vehicle however due planes high speed resultant wreckage immediately struck vehicle damaging actual hazard contributing factor hazard hazard am writing about cause ship going down planning stage demonstration re quested project officer radio operations 70 80 MHz range shut down demo fact accom plished base personnel However known club local TV stations area would using newer equipment cover event newer equipment being pressed use more TV stations commonly known live action remote TV Basically consists portable TV unit coupled high-powered transmitter make use live-coverage techniques Units transmitting frequencies actually adjacent own flying frequencies lies actual hazard transmit devices power output far exceeds power used own equipment adjacent frequency can bleed over enough point flying opera tions endangered case particular accident Clubs AMA demonstration teams should made aware potentially dangerous hazard soon possible avoid type accident occurring accident extremely close being disastrous aircraft airborne -second ship would have impacted upon car airborne another full second would have impacted upon USAF Thunderbird aircraft ship would have flying another direction loss control occurred could very well have flown crowd people estimated 3000-plus Luckily God willing case potential caution identifying hazard exercised organization giving demonstration result can disastrous mentioned above Sincerely yours s Michael S Lee President Luke Condors RC Club wind up months column item seen November 1980 issue British magazine Radio Control Models & Electronicsgives us food thought New Products RC Hobby section magazine write-up fail-safe device put Out Chromatronics mentioned previous column device neutralizes controls retards throttle either interference transmitter mal function occurs statement caught eye opening sentence mandatory conditions granting permit fly model aircraft excess 5-kg 11 lb weight provision fail-safe system stated mandates use fail-safe devices assume must some branch British government end question should consider using such fail-safe devices biggies show team models voluntary basis John Preston 7012 Elvira Court Falls Church VA 22042 Slow Year Blimp/Bruhn Continued page 65 However need reverse electrical polarity after tapering down power-off condition motor could advance opposite rotation Electronic throttles too costly heavy experiment mechanical arrangement reversing potenti ometer rotation conjunction switching polarity looked very complex Again taking expedient route hoped multiple position rotary switch could work enabled small enough stepped power changes direction pair inexpensive 12-position electronic switches modified provide two-step center off two-step reverse polarity independent control motor Actually moving switches appropriate position combinations required connecting control shafts through mechanical servo mixer blended throttle heading functions fact rotary switches positioned linear push-pull action meant travel limited less 1800 order avoid linkage jamming extremes throw Competing against commercial switch contacts necessitated about 1400 rotation cover full five-position sequence Without some compensation combination hard turn full throttle would drive pushrod other past jam limits avoid sliding pushrod/yoke arrangement added switch shafts Packaging sheet balsa cabin along three-channel radio system 24V 450 mAb drive-battery pack ballast made possibly compact serviceable simplest configuration assembly attached underneath gas bag hook end plus mating Velcro pads keep cabin shifting during thrust changes Modeling clay 120 Model Aviation 213/359-0016 Slope Squire Featured R/C SPORTSMAN SaraCen Featured RCM April 1976 Seville$6100 Featured MODEL AVIATION Apr 7 Winterhawk$57 Featured MODEL AVIATION May Hotrock Featured MODEL AVI Simitar 540 Featured RCM Oct 1978 COMPLETE PLANS WING CORE FIBERGLAS FUSELAGE PLYWOOD WING SHEETING CORE FILM WING SHEETING TAPE comes 14 X 60 yd roll $895 XHINGE$189/Pkg N EW EASY-MOUNT K&B 40 L ~dUIB vvrite 20825/z Roscoe Blvd Canoga Park CA 91306 BILL EVANS RIC AIRCRAFT Phone 213 709-0894 U IN Losing control can night mare wrong response given command can take its toll model nerves wallet Radio South know feel about hobby too avid RC enthusiasts nearly half century combined experience CONiRO modeling radio repair So avoid inflated repair costs undue service time Radio South fast economical inhouse radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control VISA 7 jrn Futaba_ 1925 E Creighton RoadPensacola FL 32504 904/478-6745 CUSTOM TUNED ENGINESGET ORGANIZEDWEVE EXPANDEDI COMPETITION ACCESSORIESHeresaseIof4sInrdyf4eSthahOIdSOOCSCALE DRAWINGSPHOTOS BOOKLETS Special GY 014 X 60 solid lines $295 ppd 4 yeas yon inoonte 0, II nagaZOUS Custom needle valves racing wheels4 MAG FILES $4950U quick fills fuel shut -a ffs & othersSend $495 pins $100 postag handling detailed brochure send 25 cents to0GM INDUSTRIESREPLA-TECI-I PO BOX 388-KiNTERNATIONAL Kustom Kraftsmanship Box 2699 Laguna HillsDOVER NH 03820CATALOGS $20048500 MC 5N818 HWY Calif 92653 Ph 714 830-5162voa 088008 97489 stuck around single landing wheel bottom cabin enabled blimp ballasted neutral buoyancy after inflation complete breathed deeply switched radio Construction Before beginning number things should clearly understood its large surface area very low mass blimp affected slightest air current includ ing too faint pilot sense Heating cooling system outlets convection currents outdoor operation impossible operating conditions unless equip blimp extremely high-thrust capability has kept away some otherwise prime sites enough say wasnt worth doubt test area first small helium balloon long string Second degree greater conventional projects success dependent amount patient attention given repetitious actions Helium escapes pathway offered including right through film material low rate course Seams must near perfect possible rapid loss buoyant gas will drastically shorten length operating time before removal ballast becomes necessary Keep mind youre tempted speed things up little after third seam Time spent being careful well worth later Finally particular design represents first generation stage development instructions precautions followed fairly closely have no doubt will have same level success have will able take real pride accomplishment Con siderable improvement should possible though Probe areas further development suggested end article own thing share rest us Rather give detailed fasten part part B instructions feel would helpful case provide illustrations supplemented notes comments blimps size relates load has support helps start determining weight radio system propulsion system other payload components including ballast Ballast important because will always helium gas leakage temperature/pressure atmospheric changes Some leeway adjust neutral buoyancy essential Dont forget include estimate weight gas bag weighed about 6 oz tail fins weight total ounces approximates ideal displacement cubic feet helium bag sea-level operaton practice some over-sizing must made allow impure gas higher elevation etc cabin pretty conventional once placement components has established Refer drawings photos further guidance Adjustment mechanical mixer linkage switch setup critical aspect assembly Two types switches diagramed Centralab 1002 usable modification isnt readily available modify Radio Shack 12-position shorting type no current interruption changing positions follows 1 Remove position detent ball socket 2 Carefully remove contact deck bottom switch 3 Use file divide inner contact ring two equal unconnected semi-circular segments 4 Remove switch shaft rotating contact disc switch mounting assembly 5 Make cannibalize another switch duplicate metal contact piece like already mounted rotating contact disc 6 Securely fasten new piece onto rotating contact disc would touch bottom deck contacts 1800 original contact piece 7 Adjust contact tension positive free reassemble switch elements Remove metal insert collar electric knob slide fully onto switch shaft tighten set-screw Make brass tin yoke solder onto collar Cut off switch shaft -in above collar Make solder pushrod retainer guide switch mounting washer Wire switch circuit test its operation thoroughly before installing cabin OK its time bite bullet make gas bag Thoroughly clean kitchen table top other very smooth hard Formica-like surface resolve stay until completion might take about week evenings following key points have common goal avoidance leakage paths First apply tape utmost care prevent bubbles gaps Second use smallest number separate pieces tape possible ie long piece rather two shorter pieces Third try avoid handling Mylar roughly folding sharply time Pinhole leaks will likely result Fourth keep clean Tape adheres best surface free grease dust release agent etc Wipe film areas apt taped later acetone before starting assembly Good luck Operation youre satisfied preliminary inflation checks using plain air detach cabin carefully work much air out bag possible Suck through fill tube really collapse flat Install balloon inflation valve onto compressed helium cyl inder prefer lay cylinder its side inflation nipple angled upward Get assis tant take precautions positively retain blimp inflate through fill tube half full cabin can reinstalled Continue inflation until just full overfilling reduces buoyancy increases gas leakage rate stresses seams Squeeze off fill tube near upper end twist lower portion tightly fold over upon itself loop rubberband repeatedly around secure Adjust ballast neutral buoyancy Eureka floats midair Charge batteries fully use Astro Flight 15-mm formula time receiver battery simple Amps X time charge March 1981 121 TLC RIC PRODUCTS Rt 1 Box 282 Prospect VA 23901 thoroughly depleted propulsion battery Opera tion sizes used averages 25 mm Its hard believe genuine excitement novice learning fly blimp confined space like living room Although weightless blimps inertia continues power off whatever direction headed last avoid probably harmless collision lamps plants candles other objects requires frantically reversing control maximum power Finesse called order control momen tum very limited thrust available tually getting hang vertical ascents descents spot landings become routine blimp can flown through hula hoop both backwards forwards calm air degree control seems practically unlimited Larger areas allow relaxed operation heading directional stability over long straight run marginal small tail fins Neverthe less theres always line turn sticks Just watch battery charge blimp small enough transported intact rear compact station wagon back seat folded down Going through rapid temperature changes outdoors indoors can dramatically change skin tension tem porarily Allow some time internal temper ature stabilize before readjusting inflation Future development concept begs modification havent yet time As example gas bag could made high-priced spread colored metalized film real impression seam-making technique should simpler Control system development can take directions electronic mixing geared servo motor thrusters different thruster location biggest opportunity may payloads airborne PA systems signs banners light-bulb changers etc Have ball Just sure pass along Summer Breeze Balloon/Hux Continued page 69 window does first convention filled up balloon nearby room started down hall auditorium entrance double door fixed center bar tightest squeeze yet applied bumper stickers over lock hinges protect balloon sharp edges People began wonder about strange placement campaign material pushed balloon through met several reporters barrage questions candidate came podium let balloon go flew up frontwhere people yet seen Previously described balloon candidate hadnt seen started opening remarks paused staring balloon banner pulled attention back what saying started over again told what expect guess just couldnt believe TV reporter asked us fly during next break film evening saw balloon few seconds announced political news next Imagine surprise have first public flight shown TV first time Lou saw balloon too Some conventions exciting othersnot programs flights buildings heavy air-conditioning equipment balloon pushed around quite lot series air-conditioning vents can play game full up full power under vent opposite between Occasionally someone would try help balloon low enough reach push like might give basketball would help give balloon little altitude would shoot ceiling. full down full power would bounce off ceiling. full up full power would scramble coming down though could hurt anyone settled imagine just sitting minding own business something blew ear type convention flying can cut flight time between recharge about 15 minutes still air could fly long hour lady puzzled transmitter took out hands What asked Its control balloon Im about crash replied calmly knowing balloon harmless After second word crash sank handed back like hot potato after disappeared crowd considered going big convention could just see delegates using big signs play badminton balloon After convention offered Bill Winter chance fly home planned way helium paid already As can read first Just Fun article quite reaciton bull-in-chinashop reaction bit surprise Con sidering room furniture 8-ft ceiling learn guess did seem lot handle could have tried gym Im sure would have enjoyed looks photo article Im sure much fun could thing have remind fliers inertialet off command long before get want go would make excellent training aid astronauts handling control jets weightless equipment Because ofour busy schedules balloon Lous blimp did fly together some time Chuck Thomas made arrangements us fly Saturday morning Xerox Train ing Center provide opportunity Dawn photograph two models pilots together Imagine will Xerox students getting up strolling through mezzanine way get morning cup coffeeand finding hot-air balloon blimp waltzing around building wide-eyed reactions lot fun guy asked unsure voice time go get cameraas thought wouldnt took eyes off thanks Ralph Heath escorting us four-hour photo session plans tell story building balloon problem some will 1 22 Model Aviation Fast realistic aerobatic kit features ABS wheelpants moulded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/03
Page Numbers: 62, 63, 64, 65, 120, 121, 122
SI Year Blimp What type RC model has following characteristics 1 flies ultra-slow speeds 2 stable yet responsive maneuverable 3 durable harmless people objects might contact 4 produces little noise pollution 5 operable inexperi enced spectators points became criteria Slow Year Blimp developed merely beginning~ author says potentially sign ifi cant THE CLUB belong has recently faced common problem flying site uncertainty Neigh bors distance lease status have threatened flying field loss continuation club pursuing alternative sites mem bers recognized need some PR Support general public can invaluable seeking use park land other community property creating favorable impression dealings private landowners frequent method obtaining citizen appre ciation modeling demonstrate graphic ally through show team performances static displays shopping malls both help forming good opinion has certain limitations Show team performances often take place before audiences predisposed receptive area suited model flying Mall displays reach deeper broad spectrum public compete antique collectors Scout troops portrait artists myriad other attactions common areas shopping malls Slides movies help can fail capture special something sets building flying models apart other activities Somehow reasoned missing elementlive operationhad introduced otherwise static setting About time list criteria began article being drawn up response need early ads First Indoor RC Contest International Modeler Show 62 Model Aviation Slow Year Blimp cruises overhead Designer/Author Lou Bruhn Checking TV camera crew cabin Lightweight payload possibilities endless RUDDER 0PWR ARE 4 040OP YB INCH NOYR LAYEMFOAM COST OF 001 MYLARALTERNATE SHAPE TO OUTLINE .L-.MATCH APTERPOW00NRUMP 5 L___ --- ___ ____ _ _ ODEMIaL POLO LINE -00 NOT CUT-r POLO PRODUECS S LAYERS OLO LINE -OONOTCUT 5 IPOLD PAROWIC-ES LAYERS CD APPROTI 5 FORWARD OP COUNTER 0 E RIRSREAARR t-4I NZIif USE 0PUCE U-SECTION 5 OW PEWS P05101015 SAITCH IF YOUR SIPITOI IDES SOT RRTCW TESIOSS SIEWNI ULTOR WIRIWO TO 151101 FUNCTIONS GONDOLA BESIWN CAN RB ABSURD 10 SUIT RADIO LAYOUT OR ODORNAROCRI RE-UN/ TASTE IN DOSION RU OR SW CHES OUVIRO Tb-PUCE MOTORS SWLT oLOIJ-'fPUT RI LWENTER UP SWITCH PLATE IDAHORIONRUTUTIRUCESITER IIIIflu QDICYoW-TORN 4 11111SERVO All DRAM CO AR lASER IAdIZ SUNTANSOLDERI AVANTILIIII2L BRASSPROM WNSS 1111 OROTATE GI ON/APP SPEEDLIBSIWAP SERVO-11ffi--jOU BRUHN HEW WOO OVERRIDE YOKE TOTS IPTEIRO FOR SWITCHES ROWING THE TMPOLE TEWIOMLO TN THE SWITCH ETOES AlTO INPUT TO ROTATING CENTER PLATE THROUHI WIPER CONTACTS SLOW YEAR BLIMP appearing magazines addition heavierthan-air classes competition featured lighterthan-air LTA category inspiraton novelty coupled large doubt success fully satisfying preceding criteria conventional heavier-than-air technology led begin investigation LTA Consider ing possibility eventual success added requirement list construction should use non-toxic materials tech niques others might readily duplicate project Initial research showed LTA practic ally unknown model magazine readers aside handful isolated efforts spread over years Nearly involved rigid dirigible frameworks aerodynamic control surfaces soon ruled Out first features being too cumbersome transport time-consuming too easily damaged latter feature involved need constant forward motion complex extensive control linkages An alternative concept non-rigid blimp controlled directed thrust began take shape arrangement prospect exceptional maneuverability includ ing reverse direction turns place nearly vertical ascents descents buoyant lift chose forego slight advantage hydrogen total safety helium have never regretted decision challenge adequately restrict extremely small gas molecules escaping achieve usefully long period between ballast readjust ments way complicated automatic remotely-controlled ballast reduction systems could avoided clear key success LTA vehicle lay method constructing gas containment bag Research indicated instrumented atmospheric research balloons shrinks somewhat heateda feature made laminated layers polyester film would take particular significance later Moresuch DuPonts Mylar Polyester has over polyester mil 001 thick availbest gas retention factors film material t able transparent rolls 40 wide 50 ft long also has exceptional tensile strength less $10 Ichose gauge best com Dawn Hux holds Hula-Hoop blimp show its stuff Tricks like take practice careful control momentum PR possibilities led undertaking March 1981 63 WIRE 5009 OUPPON TAPED TO RORTOM OP RUMP 1100K 011 OORAOOLW 1 0 Note construction sequences shad ed lines representative joining tape 1 Cut piece film double length uninflated blimp Fold film three timesfirst across length twice lengthper layout drawing marker draw cut line along edge opposite final fold Holding layers alignment cut completely through along line Result will two identical double-gore pieces Clean both sides film acetone along future seams Position firstgore piece smooth hard clean surface Start 3M /2-in double-stick tape through notch between gores follow nearer edge curve lapping tape half onto film half onto work surface Roll tape down side pen avoid direct contact fingers Prevent gaps bubbles untaping redoing affected area 2 Carefully matching film edges exactly fold second gore over Onto first Start notch pay film down onto tape eliminating gaps bubbles occur Remove tape work surface along seam Youve done itl Now repeat other three notch seams checking fold will turn same way both ends gore Handle carefully seams dont come undone Result will two blimp halves 3 Lay both blimp halves flat top another untaped edges aligned Around mid-point edge mark longitudinal alignment same place film layers Set blimp half aside Spread untaped edges remaining blimp half apart bulk hanging off edge work surface tape down long seam edge Step 1 Small view shows slicethrough blimpif made now 4 Mate blimp halvestogetheralong just-taped seam making sure nose-to-nose inside-to-inside surface orientaton Start matching together alignment spots edge press film down Step 2 direction lJpperview shows slice stage Now remove surplus tape seam lift whole assembly clear complete remain ing long seam same manner Leave about I-ft tapeless gap arrows straight part final seam Lower right final slice view 6 Prepare apply outer tape seams securely taping clean bowl upside-down near corner table Flatten blimp Out no seam overlaps another Starting notch seam hold blimp down against bowl seam interior flap folded toward point contact bowl Beginning about 1 above notch apply3M #853-in Mylarsingle stick tape overtop seam Overlap both sides equally Dont allow interior flap become smaller larger seam progressively spreading apart pulling together Complete remaining seams same manner except gap 5 Resist urge inflate blimp Turn film Inside out actually right-side-out through tapeless gap seam Work slowly beginning far thest end Careful work pays off promise between strength weight clear transparent because cost minimum order quantities exotic colored metalized laminated versions couldnt justified small project such uncertain outcome material selected problem next forming proper shape size shape traditional blimp con tours seemed like good bet tail surface small hamper control backing up ease basic problem making closed container multiple compound curves flat material planned cut tail fins foam plastic meat trays tape place About easiest way forming generally paraboloid shape end blimp attach tapering gore pieces alongside another closed loop manner parachute technique surface contour would become pleasingly smoother number individual gores increased Clearly though some compromise called between aes thetics spending rest life fastening seams together Impatient see total concept worked settled having four gore pieces stretching nose tail tapered end As turned out ideal high temperature tolerance Mylar makes heat-welding seams critical procedure Addi tionally modelers have access heat-seaming equipment series experiments done perfect alternate method Special contact cement could brushed smoothly uniformly enough Tape looked promising construct compound curvature seams full-size form build over After much trial error pondering later technique described construction sec 64 Model Aviation 7 Fillertube made same material blimp Use pattern form cylinder Part way up base end ring tube Mylartape Below ring cut about eight equal flanges fold outward work surface lay double-sticktape square approx 2-in sides Holding tape circular set down base centered tape square Lay Mylar tape down across flange innermost edge barely covers gap either side near upright tube Trim taped flange area circular outline approx 2-in diameter Lift fillertubewith double-stick tape bottom S1 8 Inflate blimp last through tapeless gap vacuum cleaner hose attached discharge outlet Blimp now resembles rumpled boxy banana Sparingly tape over gap end seams come together Tape small square patch over end Position filler tube mid way between seams point behind lengthwise center blimp Tape down flange covering gaps Point modelers knife tube make X-cut skin inside Tapeless seam gap now can finished oft permanently Reinflate blimp twist filler tube tight secure rubberband Now best part Iron blimp over except tape MonoKote setting Make tail fins cabin attachment rings handling lines etc tape place Glue Velcro pads contact cement Paintailtaped seamswith two coats polyurethane thinned 50% Take vacation reacquaint yourself family friends outside world tion developed overcomes problems involved except onesuccess relates directly amount care patience exerts later next turned attention control system satisfy number criteria provide high degree maneuver ability several axes yet consume little power light weight course should simple rugged reliable directed thrust scheme potentially met requirements addition furnishing propulsion offered nearly direct movement desired direction sharp turning might have possible theoretically just thruster seemed easier positive use located near blimps center-ofgravity way energy would pointlessly wasted pitching rolling vehicle might look dramatic wouldnt effective maneuvering nearly stationary finally opted two thrusters either side cabin suspended beneath center gas containment bag could work col lectively same direction opposite direc tions differentially same direction different speeds both thrusters mounted ends cross tube could rotate about its longitudinal axis could pointed up down changing altitude boiled down three basic functions throttle including forward/reverse capability heading altitude felt possible achieve three control channels As thrusters themselves type quiet flexible enough electric power still left wide range possibilities easiest would have remove gears pair servos use motor/amplifier circuits mount propellers directly pinion shafts motors As Luther Hux subsequently demonstrated arrangement works quite well initially resisted appeal ingly simple solution two reasons conventional transmitter control arrangrnent possible use electronic mixing violating simple-to-duplicate rule skeptical power ungeared servo motors turn propellers adequately An alternative separate propulsion system RC system using latter solely control voltage polarity used former Modifying coreless armature motor appropriate gear reduction ratio proved frustrating repositioned pinion gear could made keep slipping its shaft being able locate other low-cost substitutes gears took chance 3volt Mabuchi RE-14 motors $150 4-in diameter rubber model propellers shoved onto shafts first glance propulsion motor control seemed demand nearly linear rpm change no steps requirement potentiometer series would have served nicely Continued page 120 March 1981 65 iimp caoin sop view snowing front back motor battery pack 100 mAh receiver battery dual multi-position rotary switches pushrod yokes brick-style receiver including elevation throttle servos heading servo Du-Bro mechanical mixer pushrods switches author shown compressing blimp remove airfrom inside maximum lifting ability much airas possible must removed blimp before inflating helium assisting Slights Xerox Training Center Ralph Heath logs some blimp time Lou gives instructions INTRODUCING TIle Arlleri RJL K61 R/C ENGINE RJL Industries now produces renowned engine formerly manufactured Kraft Systems Inc schnuerle ported 61 cubic inch engine provides easy starting high performance longevity Produced finest materials workmanship quality assurance youll proud have aircraft powered K61 FEATURES INCLUDE Schnuerle Ports Boost Port Double Ball Bearings Forged Alloy Piston & Con Rod Bushed Connecting Rod 0- ring Sealed Back Cover 16 HPat 15500 RPM SUGGESTED RETAIL $13995 Muffler Included Send Free Catalog Today R J L INDUSTRIES P0 Box 5654 Pasadena CA 91107 1831 Business Center Dr Duane CA 91010 wreckage ship strike Air Force vehicle parked field ship itself actually struck ground approximately 15 ft front vehicle however due planes high speed resultant wreckage immediately struck vehicle damaging actual hazard contributing factor hazard hazard am writing about cause ship going down planning stage demonstration re quested project officer radio operations 70 80 MHz range shut down demo fact accom plished base personnel However known club local TV stations area would using newer equipment cover event newer equipment being pressed use more TV stations commonly known live action remote TV Basically consists portable TV unit coupled high-powered transmitter make use live-coverage techniques Units transmitting frequencies actually adjacent own flying frequencies lies actual hazard transmit devices power output far exceeds power used own equipment adjacent frequency can bleed over enough point flying opera tions endangered case particular accident Clubs AMA demonstration teams should made aware potentially dangerous hazard soon possible avoid type accident occurring accident extremely close being disastrous aircraft airborne -second ship would have impacted upon car airborne another full second would have impacted upon USAF Thunderbird aircraft ship would have flying another direction loss control occurred could very well have flown crowd people estimated 3000-plus Luckily God willing case potential caution identifying hazard exercised organization giving demonstration result can disastrous mentioned above Sincerely yours s Michael S Lee President Luke Condors RC Club wind up months column item seen November 1980 issue British magazine Radio Control Models & Electronicsgives us food thought New Products RC Hobby section magazine write-up fail-safe device put Out Chromatronics mentioned previous column device neutralizes controls retards throttle either interference transmitter mal function occurs statement caught eye opening sentence mandatory conditions granting permit fly model aircraft excess 5-kg 11 lb weight provision fail-safe system stated mandates use fail-safe devices assume must some branch British government end question should consider using such fail-safe devices biggies show team models voluntary basis John Preston 7012 Elvira Court Falls Church VA 22042 Slow Year Blimp/Bruhn Continued page 65 However need reverse electrical polarity after tapering down power-off condition motor could advance opposite rotation Electronic throttles too costly heavy experiment mechanical arrangement reversing potenti ometer rotation conjunction switching polarity looked very complex Again taking expedient route hoped multiple position rotary switch could work enabled small enough stepped power changes direction pair inexpensive 12-position electronic switches modified provide two-step center off two-step reverse polarity independent control motor Actually moving switches appropriate position combinations required connecting control shafts through mechanical servo mixer blended throttle heading functions fact rotary switches positioned linear push-pull action meant travel limited less 1800 order avoid linkage jamming extremes throw Competing against commercial switch contacts necessitated about 1400 rotation cover full five-position sequence Without some compensation combination hard turn full throttle would drive pushrod other past jam limits avoid sliding pushrod/yoke arrangement added switch shafts Packaging sheet balsa cabin along three-channel radio system 24V 450 mAb drive-battery pack ballast made possibly compact serviceable simplest configuration assembly attached underneath gas bag hook end plus mating Velcro pads keep cabin shifting during thrust changes Modeling clay 120 Model Aviation 213/359-0016 Slope Squire Featured R/C SPORTSMAN SaraCen Featured RCM April 1976 Seville$6100 Featured MODEL AVIATION Apr 7 Winterhawk$57 Featured MODEL AVIATION May Hotrock Featured MODEL AVI Simitar 540 Featured RCM Oct 1978 COMPLETE PLANS WING CORE FIBERGLAS FUSELAGE PLYWOOD WING SHEETING CORE FILM WING SHEETING TAPE comes 14 X 60 yd roll $895 XHINGE$189/Pkg N EW EASY-MOUNT K&B 40 L ~dUIB vvrite 20825/z Roscoe Blvd Canoga Park CA 91306 BILL EVANS RIC AIRCRAFT Phone 213 709-0894 U IN Losing control can night mare wrong response given command can take its toll model nerves wallet Radio South know feel about hobby too avid RC enthusiasts nearly half century combined experience CONiRO modeling radio repair So avoid inflated repair costs undue service time Radio South fast economical inhouse radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control VISA 7 jrn Futaba_ 1925 E Creighton RoadPensacola FL 32504 904/478-6745 CUSTOM TUNED ENGINESGET ORGANIZEDWEVE EXPANDEDI COMPETITION ACCESSORIESHeresaseIof4sInrdyf4eSthahOIdSOOCSCALE DRAWINGSPHOTOS BOOKLETS Special GY 014 X 60 solid lines $295 ppd 4 yeas yon inoonte 0, II nagaZOUS Custom needle valves racing wheels4 MAG FILES $4950U quick fills fuel shut -a ffs & othersSend $495 pins $100 postag handling detailed brochure send 25 cents to0GM INDUSTRIESREPLA-TECI-I PO BOX 388-KiNTERNATIONAL Kustom Kraftsmanship Box 2699 Laguna HillsDOVER NH 03820CATALOGS $20048500 MC 5N818 HWY Calif 92653 Ph 714 830-5162voa 088008 97489 stuck around single landing wheel bottom cabin enabled blimp ballasted neutral buoyancy after inflation complete breathed deeply switched radio Construction Before beginning number things should clearly understood its large surface area very low mass blimp affected slightest air current includ ing too faint pilot sense Heating cooling system outlets convection currents outdoor operation impossible operating conditions unless equip blimp extremely high-thrust capability has kept away some otherwise prime sites enough say wasnt worth doubt test area first small helium balloon long string Second degree greater conventional projects success dependent amount patient attention given repetitious actions Helium escapes pathway offered including right through film material low rate course Seams must near perfect possible rapid loss buoyant gas will drastically shorten length operating time before removal ballast becomes necessary Keep mind youre tempted speed things up little after third seam Time spent being careful well worth later Finally particular design represents first generation stage development instructions precautions followed fairly closely have no doubt will have same level success have will able take real pride accomplishment Con siderable improvement should possible though Probe areas further development suggested end article own thing share rest us Rather give detailed fasten part part B instructions feel would helpful case provide illustrations supplemented notes comments blimps size relates load has support helps start determining weight radio system propulsion system other payload components including ballast Ballast important because will always helium gas leakage temperature/pressure atmospheric changes Some leeway adjust neutral buoyancy essential Dont forget include estimate weight gas bag weighed about 6 oz tail fins weight total ounces approximates ideal displacement cubic feet helium bag sea-level operaton practice some over-sizing must made allow impure gas higher elevation etc cabin pretty conventional once placement components has established Refer drawings photos further guidance Adjustment mechanical mixer linkage switch setup critical aspect assembly Two types switches diagramed Centralab 1002 usable modification isnt readily available modify Radio Shack 12-position shorting type no current interruption changing positions follows 1 Remove position detent ball socket 2 Carefully remove contact deck bottom switch 3 Use file divide inner contact ring two equal unconnected semi-circular segments 4 Remove switch shaft rotating contact disc switch mounting assembly 5 Make cannibalize another switch duplicate metal contact piece like already mounted rotating contact disc 6 Securely fasten new piece onto rotating contact disc would touch bottom deck contacts 1800 original contact piece 7 Adjust contact tension positive free reassemble switch elements Remove metal insert collar electric knob slide fully onto switch shaft tighten set-screw Make brass tin yoke solder onto collar Cut off switch shaft -in above collar Make solder pushrod retainer guide switch mounting washer Wire switch circuit test its operation thoroughly before installing cabin OK its time bite bullet make gas bag Thoroughly clean kitchen table top other very smooth hard Formica-like surface resolve stay until completion might take about week evenings following key points have common goal avoidance leakage paths First apply tape utmost care prevent bubbles gaps Second use smallest number separate pieces tape possible ie long piece rather two shorter pieces Third try avoid handling Mylar roughly folding sharply time Pinhole leaks will likely result Fourth keep clean Tape adheres best surface free grease dust release agent etc Wipe film areas apt taped later acetone before starting assembly Good luck Operation youre satisfied preliminary inflation checks using plain air detach cabin carefully work much air out bag possible Suck through fill tube really collapse flat Install balloon inflation valve onto compressed helium cyl inder prefer lay cylinder its side inflation nipple angled upward Get assis tant take precautions positively retain blimp inflate through fill tube half full cabin can reinstalled Continue inflation until just full overfilling reduces buoyancy increases gas leakage rate stresses seams Squeeze off fill tube near upper end twist lower portion tightly fold over upon itself loop rubberband repeatedly around secure Adjust ballast neutral buoyancy Eureka floats midair Charge batteries fully use Astro Flight 15-mm formula time receiver battery simple Amps X time charge March 1981 121 TLC RIC PRODUCTS Rt 1 Box 282 Prospect VA 23901 thoroughly depleted propulsion battery Opera tion sizes used averages 25 mm Its hard believe genuine excitement novice learning fly blimp confined space like living room Although weightless blimps inertia continues power off whatever direction headed last avoid probably harmless collision lamps plants candles other objects requires frantically reversing control maximum power Finesse called order control momen tum very limited thrust available tually getting hang vertical ascents descents spot landings become routine blimp can flown through hula hoop both backwards forwards calm air degree control seems practically unlimited Larger areas allow relaxed operation heading directional stability over long straight run marginal small tail fins Neverthe less theres always line turn sticks Just watch battery charge blimp small enough transported intact rear compact station wagon back seat folded down Going through rapid temperature changes outdoors indoors can dramatically change skin tension tem porarily Allow some time internal temper ature stabilize before readjusting inflation Future development concept begs modification havent yet time As example gas bag could made high-priced spread colored metalized film real impression seam-making technique should simpler Control system development can take directions electronic mixing geared servo motor thrusters different thruster location biggest opportunity may payloads airborne PA systems signs banners light-bulb changers etc Have ball Just sure pass along Summer Breeze Balloon/Hux Continued page 69 window does first convention filled up balloon nearby room started down hall auditorium entrance double door fixed center bar tightest squeeze yet applied bumper stickers over lock hinges protect balloon sharp edges People began wonder about strange placement campaign material pushed balloon through met several reporters barrage questions candidate came podium let balloon go flew up frontwhere people yet seen Previously described balloon candidate hadnt seen started opening remarks paused staring balloon banner pulled attention back what saying started over again told what expect guess just couldnt believe TV reporter asked us fly during next break film evening saw balloon few seconds announced political news next Imagine surprise have first public flight shown TV first time Lou saw balloon too Some conventions exciting othersnot programs flights buildings heavy air-conditioning equipment balloon pushed around quite lot series air-conditioning vents can play game full up full power under vent opposite between Occasionally someone would try help balloon low enough reach push like might give basketball would help give balloon little altitude would shoot ceiling. full down full power would bounce off ceiling. full up full power would scramble coming down though could hurt anyone settled imagine just sitting minding own business something blew ear type convention flying can cut flight time between recharge about 15 minutes still air could fly long hour lady puzzled transmitter took out hands What asked Its control balloon Im about crash replied calmly knowing balloon harmless After second word crash sank handed back like hot potato after disappeared crowd considered going big convention could just see delegates using big signs play badminton balloon After convention offered Bill Winter chance fly home planned way helium paid already As can read first Just Fun article quite reaciton bull-in-chinashop reaction bit surprise Con sidering room furniture 8-ft ceiling learn guess did seem lot handle could have tried gym Im sure would have enjoyed looks photo article Im sure much fun could thing have remind fliers inertialet off command long before get want go would make excellent training aid astronauts handling control jets weightless equipment Because ofour busy schedules balloon Lous blimp did fly together some time Chuck Thomas made arrangements us fly Saturday morning Xerox Train ing Center provide opportunity Dawn photograph two models pilots together Imagine will Xerox students getting up strolling through mezzanine way get morning cup coffeeand finding hot-air balloon blimp waltzing around building wide-eyed reactions lot fun guy asked unsure voice time go get cameraas thought wouldnt took eyes off thanks Ralph Heath escorting us four-hour photo session plans tell story building balloon problem some will 1 22 Model Aviation Fast realistic aerobatic kit features ABS wheelpants moulded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/03
Page Numbers: 62, 63, 64, 65, 120, 121, 122
SI Year Blimp What type RC model has following characteristics 1 flies ultra-slow speeds 2 stable yet responsive maneuverable 3 durable harmless people objects might contact 4 produces little noise pollution 5 operable inexperi enced spectators points became criteria Slow Year Blimp developed merely beginning~ author says potentially sign ifi cant THE CLUB belong has recently faced common problem flying site uncertainty Neigh bors distance lease status have threatened flying field loss continuation club pursuing alternative sites mem bers recognized need some PR Support general public can invaluable seeking use park land other community property creating favorable impression dealings private landowners frequent method obtaining citizen appre ciation modeling demonstrate graphic ally through show team performances static displays shopping malls both help forming good opinion has certain limitations Show team performances often take place before audiences predisposed receptive area suited model flying Mall displays reach deeper broad spectrum public compete antique collectors Scout troops portrait artists myriad other attactions common areas shopping malls Slides movies help can fail capture special something sets building flying models apart other activities Somehow reasoned missing elementlive operationhad introduced otherwise static setting About time list criteria began article being drawn up response need early ads First Indoor RC Contest International Modeler Show 62 Model Aviation Slow Year Blimp cruises overhead Designer/Author Lou Bruhn Checking TV camera crew cabin Lightweight payload possibilities endless RUDDER 0PWR ARE 4 040OP YB INCH NOYR LAYEMFOAM COST OF 001 MYLARALTERNATE SHAPE TO OUTLINE .L-.MATCH APTERPOW00NRUMP 5 L___ --- ___ ____ _ _ ODEMIaL POLO LINE -00 NOT CUT-r POLO PRODUECS S LAYERS OLO LINE -OONOTCUT 5 IPOLD PAROWIC-ES LAYERS CD APPROTI 5 FORWARD OP COUNTER 0 E RIRSREAARR t-4I NZIif USE 0PUCE U-SECTION 5 OW PEWS P05101015 SAITCH IF YOUR SIPITOI IDES SOT RRTCW TESIOSS SIEWNI ULTOR WIRIWO TO 151101 FUNCTIONS GONDOLA BESIWN CAN RB ABSURD 10 SUIT RADIO LAYOUT OR ODORNAROCRI RE-UN/ TASTE IN DOSION RU OR SW CHES OUVIRO Tb-PUCE MOTORS SWLT oLOIJ-'fPUT RI LWENTER UP SWITCH PLATE IDAHORIONRUTUTIRUCESITER IIIIflu QDICYoW-TORN 4 11111SERVO All DRAM CO AR lASER IAdIZ SUNTANSOLDERI AVANTILIIII2L BRASSPROM WNSS 1111 OROTATE GI ON/APP SPEEDLIBSIWAP SERVO-11ffi--jOU BRUHN HEW WOO OVERRIDE YOKE TOTS IPTEIRO FOR SWITCHES ROWING THE TMPOLE TEWIOMLO TN THE SWITCH ETOES AlTO INPUT TO ROTATING CENTER PLATE THROUHI WIPER CONTACTS SLOW YEAR BLIMP appearing magazines addition heavierthan-air classes competition featured lighterthan-air LTA category inspiraton novelty coupled large doubt success fully satisfying preceding criteria conventional heavier-than-air technology led begin investigation LTA Consider ing possibility eventual success added requirement list construction should use non-toxic materials tech niques others might readily duplicate project Initial research showed LTA practic ally unknown model magazine readers aside handful isolated efforts spread over years Nearly involved rigid dirigible frameworks aerodynamic control surfaces soon ruled Out first features being too cumbersome transport time-consuming too easily damaged latter feature involved need constant forward motion complex extensive control linkages An alternative concept non-rigid blimp controlled directed thrust began take shape arrangement prospect exceptional maneuverability includ ing reverse direction turns place nearly vertical ascents descents buoyant lift chose forego slight advantage hydrogen total safety helium have never regretted decision challenge adequately restrict extremely small gas molecules escaping achieve usefully long period between ballast readjust ments way complicated automatic remotely-controlled ballast reduction systems could avoided clear key success LTA vehicle lay method constructing gas containment bag Research indicated instrumented atmospheric research balloons shrinks somewhat heateda feature made laminated layers polyester film would take particular significance later Moresuch DuPonts Mylar Polyester has over polyester mil 001 thick availbest gas retention factors film material t able transparent rolls 40 wide 50 ft long also has exceptional tensile strength less $10 Ichose gauge best com Dawn Hux holds Hula-Hoop blimp show its stuff Tricks like take practice careful control momentum PR possibilities led undertaking March 1981 63 WIRE 5009 OUPPON TAPED TO RORTOM OP RUMP 1100K 011 OORAOOLW 1 0 Note construction sequences shad ed lines representative joining tape 1 Cut piece film double length uninflated blimp Fold film three timesfirst across length twice lengthper layout drawing marker draw cut line along edge opposite final fold Holding layers alignment cut completely through along line Result will two identical double-gore pieces Clean both sides film acetone along future seams Position firstgore piece smooth hard clean surface Start 3M /2-in double-stick tape through notch between gores follow nearer edge curve lapping tape half onto film half onto work surface Roll tape down side pen avoid direct contact fingers Prevent gaps bubbles untaping redoing affected area 2 Carefully matching film edges exactly fold second gore over Onto first Start notch pay film down onto tape eliminating gaps bubbles occur Remove tape work surface along seam Youve done itl Now repeat other three notch seams checking fold will turn same way both ends gore Handle carefully seams dont come undone Result will two blimp halves 3 Lay both blimp halves flat top another untaped edges aligned Around mid-point edge mark longitudinal alignment same place film layers Set blimp half aside Spread untaped edges remaining blimp half apart bulk hanging off edge work surface tape down long seam edge Step 1 Small view shows slicethrough blimpif made now 4 Mate blimp halvestogetheralong just-taped seam making sure nose-to-nose inside-to-inside surface orientaton Start matching together alignment spots edge press film down Step 2 direction lJpperview shows slice stage Now remove surplus tape seam lift whole assembly clear complete remain ing long seam same manner Leave about I-ft tapeless gap arrows straight part final seam Lower right final slice view 6 Prepare apply outer tape seams securely taping clean bowl upside-down near corner table Flatten blimp Out no seam overlaps another Starting notch seam hold blimp down against bowl seam interior flap folded toward point contact bowl Beginning about 1 above notch apply3M #853-in Mylarsingle stick tape overtop seam Overlap both sides equally Dont allow interior flap become smaller larger seam progressively spreading apart pulling together Complete remaining seams same manner except gap 5 Resist urge inflate blimp Turn film Inside out actually right-side-out through tapeless gap seam Work slowly beginning far thest end Careful work pays off promise between strength weight clear transparent because cost minimum order quantities exotic colored metalized laminated versions couldnt justified small project such uncertain outcome material selected problem next forming proper shape size shape traditional blimp con tours seemed like good bet tail surface small hamper control backing up ease basic problem making closed container multiple compound curves flat material planned cut tail fins foam plastic meat trays tape place About easiest way forming generally paraboloid shape end blimp attach tapering gore pieces alongside another closed loop manner parachute technique surface contour would become pleasingly smoother number individual gores increased Clearly though some compromise called between aes thetics spending rest life fastening seams together Impatient see total concept worked settled having four gore pieces stretching nose tail tapered end As turned out ideal high temperature tolerance Mylar makes heat-welding seams critical procedure Addi tionally modelers have access heat-seaming equipment series experiments done perfect alternate method Special contact cement could brushed smoothly uniformly enough Tape looked promising construct compound curvature seams full-size form build over After much trial error pondering later technique described construction sec 64 Model Aviation 7 Fillertube made same material blimp Use pattern form cylinder Part way up base end ring tube Mylartape Below ring cut about eight equal flanges fold outward work surface lay double-sticktape square approx 2-in sides Holding tape circular set down base centered tape square Lay Mylar tape down across flange innermost edge barely covers gap either side near upright tube Trim taped flange area circular outline approx 2-in diameter Lift fillertubewith double-stick tape bottom S1 8 Inflate blimp last through tapeless gap vacuum cleaner hose attached discharge outlet Blimp now resembles rumpled boxy banana Sparingly tape over gap end seams come together Tape small square patch over end Position filler tube mid way between seams point behind lengthwise center blimp Tape down flange covering gaps Point modelers knife tube make X-cut skin inside Tapeless seam gap now can finished oft permanently Reinflate blimp twist filler tube tight secure rubberband Now best part Iron blimp over except tape MonoKote setting Make tail fins cabin attachment rings handling lines etc tape place Glue Velcro pads contact cement Paintailtaped seamswith two coats polyurethane thinned 50% Take vacation reacquaint yourself family friends outside world tion developed overcomes problems involved except onesuccess relates directly amount care patience exerts later next turned attention control system satisfy number criteria provide high degree maneuver ability several axes yet consume little power light weight course should simple rugged reliable directed thrust scheme potentially met requirements addition furnishing propulsion offered nearly direct movement desired direction sharp turning might have possible theoretically just thruster seemed easier positive use located near blimps center-ofgravity way energy would pointlessly wasted pitching rolling vehicle might look dramatic wouldnt effective maneuvering nearly stationary finally opted two thrusters either side cabin suspended beneath center gas containment bag could work col lectively same direction opposite direc tions differentially same direction different speeds both thrusters mounted ends cross tube could rotate about its longitudinal axis could pointed up down changing altitude boiled down three basic functions throttle including forward/reverse capability heading altitude felt possible achieve three control channels As thrusters themselves type quiet flexible enough electric power still left wide range possibilities easiest would have remove gears pair servos use motor/amplifier circuits mount propellers directly pinion shafts motors As Luther Hux subsequently demonstrated arrangement works quite well initially resisted appeal ingly simple solution two reasons conventional transmitter control arrangrnent possible use electronic mixing violating simple-to-duplicate rule skeptical power ungeared servo motors turn propellers adequately An alternative separate propulsion system RC system using latter solely control voltage polarity used former Modifying coreless armature motor appropriate gear reduction ratio proved frustrating repositioned pinion gear could made keep slipping its shaft being able locate other low-cost substitutes gears took chance 3volt Mabuchi RE-14 motors $150 4-in diameter rubber model propellers shoved onto shafts first glance propulsion motor control seemed demand nearly linear rpm change no steps requirement potentiometer series would have served nicely Continued page 120 March 1981 65 iimp caoin sop view snowing front back motor battery pack 100 mAh receiver battery dual multi-position rotary switches pushrod yokes brick-style receiver including elevation throttle servos heading servo Du-Bro mechanical mixer pushrods switches author shown compressing blimp remove airfrom inside maximum lifting ability much airas possible must removed blimp before inflating helium assisting Slights Xerox Training Center Ralph Heath logs some blimp time Lou gives instructions INTRODUCING TIle Arlleri RJL K61 R/C ENGINE RJL Industries now produces renowned engine formerly manufactured Kraft Systems Inc schnuerle ported 61 cubic inch engine provides easy starting high performance longevity Produced finest materials workmanship quality assurance youll proud have aircraft powered K61 FEATURES INCLUDE Schnuerle Ports Boost Port Double Ball Bearings Forged Alloy Piston & Con Rod Bushed Connecting Rod 0- ring Sealed Back Cover 16 HPat 15500 RPM SUGGESTED RETAIL $13995 Muffler Included Send Free Catalog Today R J L INDUSTRIES P0 Box 5654 Pasadena CA 91107 1831 Business Center Dr Duane CA 91010 wreckage ship strike Air Force vehicle parked field ship itself actually struck ground approximately 15 ft front vehicle however due planes high speed resultant wreckage immediately struck vehicle damaging actual hazard contributing factor hazard hazard am writing about cause ship going down planning stage demonstration re quested project officer radio operations 70 80 MHz range shut down demo fact accom plished base personnel However known club local TV stations area would using newer equipment cover event newer equipment being pressed use more TV stations commonly known live action remote TV Basically consists portable TV unit coupled high-powered transmitter make use live-coverage techniques Units transmitting frequencies actually adjacent own flying frequencies lies actual hazard transmit devices power output far exceeds power used own equipment adjacent frequency can bleed over enough point flying opera tions endangered case particular accident Clubs AMA demonstration teams should made aware potentially dangerous hazard soon possible avoid type accident occurring accident extremely close being disastrous aircraft airborne -second ship would have impacted upon car airborne another full second would have impacted upon USAF Thunderbird aircraft ship would have flying another direction loss control occurred could very well have flown crowd people estimated 3000-plus Luckily God willing case potential caution identifying hazard exercised organization giving demonstration result can disastrous mentioned above Sincerely yours s Michael S Lee President Luke Condors RC Club wind up months column item seen November 1980 issue British magazine Radio Control Models & Electronicsgives us food thought New Products RC Hobby section magazine write-up fail-safe device put Out Chromatronics mentioned previous column device neutralizes controls retards throttle either interference transmitter mal function occurs statement caught eye opening sentence mandatory conditions granting permit fly model aircraft excess 5-kg 11 lb weight provision fail-safe system stated mandates use fail-safe devices assume must some branch British government end question should consider using such fail-safe devices biggies show team models voluntary basis John Preston 7012 Elvira Court Falls Church VA 22042 Slow Year Blimp/Bruhn Continued page 65 However need reverse electrical polarity after tapering down power-off condition motor could advance opposite rotation Electronic throttles too costly heavy experiment mechanical arrangement reversing potenti ometer rotation conjunction switching polarity looked very complex Again taking expedient route hoped multiple position rotary switch could work enabled small enough stepped power changes direction pair inexpensive 12-position electronic switches modified provide two-step center off two-step reverse polarity independent control motor Actually moving switches appropriate position combinations required connecting control shafts through mechanical servo mixer blended throttle heading functions fact rotary switches positioned linear push-pull action meant travel limited less 1800 order avoid linkage jamming extremes throw Competing against commercial switch contacts necessitated about 1400 rotation cover full five-position sequence Without some compensation combination hard turn full throttle would drive pushrod other past jam limits avoid sliding pushrod/yoke arrangement added switch shafts Packaging sheet balsa cabin along three-channel radio system 24V 450 mAb drive-battery pack ballast made possibly compact serviceable simplest configuration assembly attached underneath gas bag hook end plus mating Velcro pads keep cabin shifting during thrust changes Modeling clay 120 Model Aviation 213/359-0016 Slope Squire Featured R/C SPORTSMAN SaraCen Featured RCM April 1976 Seville$6100 Featured MODEL AVIATION Apr 7 Winterhawk$57 Featured MODEL AVIATION May Hotrock Featured MODEL AVI Simitar 540 Featured RCM Oct 1978 COMPLETE PLANS WING CORE FIBERGLAS FUSELAGE PLYWOOD WING SHEETING CORE FILM WING SHEETING TAPE comes 14 X 60 yd roll $895 XHINGE$189/Pkg N EW EASY-MOUNT K&B 40 L ~dUIB vvrite 20825/z Roscoe Blvd Canoga Park CA 91306 BILL EVANS RIC AIRCRAFT Phone 213 709-0894 U IN Losing control can night mare wrong response given command can take its toll model nerves wallet Radio South know feel about hobby too avid RC enthusiasts nearly half century combined experience CONiRO modeling radio repair So avoid inflated repair costs undue service time Radio South fast economical inhouse radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control VISA 7 jrn Futaba_ 1925 E Creighton RoadPensacola FL 32504 904/478-6745 CUSTOM TUNED ENGINESGET ORGANIZEDWEVE EXPANDEDI COMPETITION ACCESSORIESHeresaseIof4sInrdyf4eSthahOIdSOOCSCALE DRAWINGSPHOTOS BOOKLETS Special GY 014 X 60 solid lines $295 ppd 4 yeas yon inoonte 0, II nagaZOUS Custom needle valves racing wheels4 MAG FILES $4950U quick fills fuel shut -a ffs & othersSend $495 pins $100 postag handling detailed brochure send 25 cents to0GM INDUSTRIESREPLA-TECI-I PO BOX 388-KiNTERNATIONAL Kustom Kraftsmanship Box 2699 Laguna HillsDOVER NH 03820CATALOGS $20048500 MC 5N818 HWY Calif 92653 Ph 714 830-5162voa 088008 97489 stuck around single landing wheel bottom cabin enabled blimp ballasted neutral buoyancy after inflation complete breathed deeply switched radio Construction Before beginning number things should clearly understood its large surface area very low mass blimp affected slightest air current includ ing too faint pilot sense Heating cooling system outlets convection currents outdoor operation impossible operating conditions unless equip blimp extremely high-thrust capability has kept away some otherwise prime sites enough say wasnt worth doubt test area first small helium balloon long string Second degree greater conventional projects success dependent amount patient attention given repetitious actions Helium escapes pathway offered including right through film material low rate course Seams must near perfect possible rapid loss buoyant gas will drastically shorten length operating time before removal ballast becomes necessary Keep mind youre tempted speed things up little after third seam Time spent being careful well worth later Finally particular design represents first generation stage development instructions precautions followed fairly closely have no doubt will have same level success have will able take real pride accomplishment Con siderable improvement should possible though Probe areas further development suggested end article own thing share rest us Rather give detailed fasten part part B instructions feel would helpful case provide illustrations supplemented notes comments blimps size relates load has support helps start determining weight radio system propulsion system other payload components including ballast Ballast important because will always helium gas leakage temperature/pressure atmospheric changes Some leeway adjust neutral buoyancy essential Dont forget include estimate weight gas bag weighed about 6 oz tail fins weight total ounces approximates ideal displacement cubic feet helium bag sea-level operaton practice some over-sizing must made allow impure gas higher elevation etc cabin pretty conventional once placement components has established Refer drawings photos further guidance Adjustment mechanical mixer linkage switch setup critical aspect assembly Two types switches diagramed Centralab 1002 usable modification isnt readily available modify Radio Shack 12-position shorting type no current interruption changing positions follows 1 Remove position detent ball socket 2 Carefully remove contact deck bottom switch 3 Use file divide inner contact ring two equal unconnected semi-circular segments 4 Remove switch shaft rotating contact disc switch mounting assembly 5 Make cannibalize another switch duplicate metal contact piece like already mounted rotating contact disc 6 Securely fasten new piece onto rotating contact disc would touch bottom deck contacts 1800 original contact piece 7 Adjust contact tension positive free reassemble switch elements Remove metal insert collar electric knob slide fully onto switch shaft tighten set-screw Make brass tin yoke solder onto collar Cut off switch shaft -in above collar Make solder pushrod retainer guide switch mounting washer Wire switch circuit test its operation thoroughly before installing cabin OK its time bite bullet make gas bag Thoroughly clean kitchen table top other very smooth hard Formica-like surface resolve stay until completion might take about week evenings following key points have common goal avoidance leakage paths First apply tape utmost care prevent bubbles gaps Second use smallest number separate pieces tape possible ie long piece rather two shorter pieces Third try avoid handling Mylar roughly folding sharply time Pinhole leaks will likely result Fourth keep clean Tape adheres best surface free grease dust release agent etc Wipe film areas apt taped later acetone before starting assembly Good luck Operation youre satisfied preliminary inflation checks using plain air detach cabin carefully work much air out bag possible Suck through fill tube really collapse flat Install balloon inflation valve onto compressed helium cyl inder prefer lay cylinder its side inflation nipple angled upward Get assis tant take precautions positively retain blimp inflate through fill tube half full cabin can reinstalled Continue inflation until just full overfilling reduces buoyancy increases gas leakage rate stresses seams Squeeze off fill tube near upper end twist lower portion tightly fold over upon itself loop rubberband repeatedly around secure Adjust ballast neutral buoyancy Eureka floats midair Charge batteries fully use Astro Flight 15-mm formula time receiver battery simple Amps X time charge March 1981 121 TLC RIC PRODUCTS Rt 1 Box 282 Prospect VA 23901 thoroughly depleted propulsion battery Opera tion sizes used averages 25 mm Its hard believe genuine excitement novice learning fly blimp confined space like living room Although weightless blimps inertia continues power off whatever direction headed last avoid probably harmless collision lamps plants candles other objects requires frantically reversing control maximum power Finesse called order control momen tum very limited thrust available tually getting hang vertical ascents descents spot landings become routine blimp can flown through hula hoop both backwards forwards calm air degree control seems practically unlimited Larger areas allow relaxed operation heading directional stability over long straight run marginal small tail fins Neverthe less theres always line turn sticks Just watch battery charge blimp small enough transported intact rear compact station wagon back seat folded down Going through rapid temperature changes outdoors indoors can dramatically change skin tension tem porarily Allow some time internal temper ature stabilize before readjusting inflation Future development concept begs modification havent yet time As example gas bag could made high-priced spread colored metalized film real impression seam-making technique should simpler Control system development can take directions electronic mixing geared servo motor thrusters different thruster location biggest opportunity may payloads airborne PA systems signs banners light-bulb changers etc Have ball Just sure pass along Summer Breeze Balloon/Hux Continued page 69 window does first convention filled up balloon nearby room started down hall auditorium entrance double door fixed center bar tightest squeeze yet applied bumper stickers over lock hinges protect balloon sharp edges People began wonder about strange placement campaign material pushed balloon through met several reporters barrage questions candidate came podium let balloon go flew up frontwhere people yet seen Previously described balloon candidate hadnt seen started opening remarks paused staring balloon banner pulled attention back what saying started over again told what expect guess just couldnt believe TV reporter asked us fly during next break film evening saw balloon few seconds announced political news next Imagine surprise have first public flight shown TV first time Lou saw balloon too Some conventions exciting othersnot programs flights buildings heavy air-conditioning equipment balloon pushed around quite lot series air-conditioning vents can play game full up full power under vent opposite between Occasionally someone would try help balloon low enough reach push like might give basketball would help give balloon little altitude would shoot ceiling. full down full power would bounce off ceiling. full up full power would scramble coming down though could hurt anyone settled imagine just sitting minding own business something blew ear type convention flying can cut flight time between recharge about 15 minutes still air could fly long hour lady puzzled transmitter took out hands What asked Its control balloon Im about crash replied calmly knowing balloon harmless After second word crash sank handed back like hot potato after disappeared crowd considered going big convention could just see delegates using big signs play badminton balloon After convention offered Bill Winter chance fly home planned way helium paid already As can read first Just Fun article quite reaciton bull-in-chinashop reaction bit surprise Con sidering room furniture 8-ft ceiling learn guess did seem lot handle could have tried gym Im sure would have enjoyed looks photo article Im sure much fun could thing have remind fliers inertialet off command long before get want go would make excellent training aid astronauts handling control jets weightless equipment Because ofour busy schedules balloon Lous blimp did fly together some time Chuck Thomas made arrangements us fly Saturday morning Xerox Train ing Center provide opportunity Dawn photograph two models pilots together Imagine will Xerox students getting up strolling through mezzanine way get morning cup coffeeand finding hot-air balloon blimp waltzing around building wide-eyed reactions lot fun guy asked unsure voice time go get cameraas thought wouldnt took eyes off thanks Ralph Heath escorting us four-hour photo session plans tell story building balloon problem some will 1 22 Model Aviation Fast realistic aerobatic kit features ABS wheelpants moulded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/03
Page Numbers: 62, 63, 64, 65, 120, 121, 122
SI Year Blimp What type RC model has following characteristics 1 flies ultra-slow speeds 2 stable yet responsive maneuverable 3 durable harmless people objects might contact 4 produces little noise pollution 5 operable inexperi enced spectators points became criteria Slow Year Blimp developed merely beginning~ author says potentially sign ifi cant THE CLUB belong has recently faced common problem flying site uncertainty Neigh bors distance lease status have threatened flying field loss continuation club pursuing alternative sites mem bers recognized need some PR Support general public can invaluable seeking use park land other community property creating favorable impression dealings private landowners frequent method obtaining citizen appre ciation modeling demonstrate graphic ally through show team performances static displays shopping malls both help forming good opinion has certain limitations Show team performances often take place before audiences predisposed receptive area suited model flying Mall displays reach deeper broad spectrum public compete antique collectors Scout troops portrait artists myriad other attactions common areas shopping malls Slides movies help can fail capture special something sets building flying models apart other activities Somehow reasoned missing elementlive operationhad introduced otherwise static setting About time list criteria began article being drawn up response need early ads First Indoor RC Contest International Modeler Show 62 Model Aviation Slow Year Blimp cruises overhead Designer/Author Lou Bruhn Checking TV camera crew cabin Lightweight payload possibilities endless RUDDER 0PWR ARE 4 040OP YB INCH NOYR LAYEMFOAM COST OF 001 MYLARALTERNATE SHAPE TO OUTLINE .L-.MATCH APTERPOW00NRUMP 5 L___ --- ___ ____ _ _ ODEMIaL POLO LINE -00 NOT CUT-r POLO PRODUECS S LAYERS OLO LINE -OONOTCUT 5 IPOLD PAROWIC-ES LAYERS CD APPROTI 5 FORWARD OP COUNTER 0 E RIRSREAARR t-4I NZIif USE 0PUCE U-SECTION 5 OW PEWS P05101015 SAITCH IF YOUR SIPITOI IDES SOT RRTCW TESIOSS SIEWNI ULTOR WIRIWO TO 151101 FUNCTIONS GONDOLA BESIWN CAN RB ABSURD 10 SUIT RADIO LAYOUT OR ODORNAROCRI RE-UN/ TASTE IN DOSION RU OR SW CHES OUVIRO Tb-PUCE MOTORS SWLT oLOIJ-'fPUT RI LWENTER UP SWITCH PLATE IDAHORIONRUTUTIRUCESITER IIIIflu QDICYoW-TORN 4 11111SERVO All DRAM CO AR lASER IAdIZ SUNTANSOLDERI AVANTILIIII2L BRASSPROM WNSS 1111 OROTATE GI ON/APP SPEEDLIBSIWAP SERVO-11ffi--jOU BRUHN HEW WOO OVERRIDE YOKE TOTS IPTEIRO FOR SWITCHES ROWING THE TMPOLE TEWIOMLO TN THE SWITCH ETOES AlTO INPUT TO ROTATING CENTER PLATE THROUHI WIPER CONTACTS SLOW YEAR BLIMP appearing magazines addition heavierthan-air classes competition featured lighterthan-air LTA category inspiraton novelty coupled large doubt success fully satisfying preceding criteria conventional heavier-than-air technology led begin investigation LTA Consider ing possibility eventual success added requirement list construction should use non-toxic materials tech niques others might readily duplicate project Initial research showed LTA practic ally unknown model magazine readers aside handful isolated efforts spread over years Nearly involved rigid dirigible frameworks aerodynamic control surfaces soon ruled Out first features being too cumbersome transport time-consuming too easily damaged latter feature involved need constant forward motion complex extensive control linkages An alternative concept non-rigid blimp controlled directed thrust began take shape arrangement prospect exceptional maneuverability includ ing reverse direction turns place nearly vertical ascents descents buoyant lift chose forego slight advantage hydrogen total safety helium have never regretted decision challenge adequately restrict extremely small gas molecules escaping achieve usefully long period between ballast readjust ments way complicated automatic remotely-controlled ballast reduction systems could avoided clear key success LTA vehicle lay method constructing gas containment bag Research indicated instrumented atmospheric research balloons shrinks somewhat heateda feature made laminated layers polyester film would take particular significance later Moresuch DuPonts Mylar Polyester has over polyester mil 001 thick availbest gas retention factors film material t able transparent rolls 40 wide 50 ft long also has exceptional tensile strength less $10 Ichose gauge best com Dawn Hux holds Hula-Hoop blimp show its stuff Tricks like take practice careful control momentum PR possibilities led undertaking March 1981 63 WIRE 5009 OUPPON TAPED TO RORTOM OP RUMP 1100K 011 OORAOOLW 1 0 Note construction sequences shad ed lines representative joining tape 1 Cut piece film double length uninflated blimp Fold film three timesfirst across length twice lengthper layout drawing marker draw cut line along edge opposite final fold Holding layers alignment cut completely through along line Result will two identical double-gore pieces Clean both sides film acetone along future seams Position firstgore piece smooth hard clean surface Start 3M /2-in double-stick tape through notch between gores follow nearer edge curve lapping tape half onto film half onto work surface Roll tape down side pen avoid direct contact fingers Prevent gaps bubbles untaping redoing affected area 2 Carefully matching film edges exactly fold second gore over Onto first Start notch pay film down onto tape eliminating gaps bubbles occur Remove tape work surface along seam Youve done itl Now repeat other three notch seams checking fold will turn same way both ends gore Handle carefully seams dont come undone Result will two blimp halves 3 Lay both blimp halves flat top another untaped edges aligned Around mid-point edge mark longitudinal alignment same place film layers Set blimp half aside Spread untaped edges remaining blimp half apart bulk hanging off edge work surface tape down long seam edge Step 1 Small view shows slicethrough blimpif made now 4 Mate blimp halvestogetheralong just-taped seam making sure nose-to-nose inside-to-inside surface orientaton Start matching together alignment spots edge press film down Step 2 direction lJpperview shows slice stage Now remove surplus tape seam lift whole assembly clear complete remain ing long seam same manner Leave about I-ft tapeless gap arrows straight part final seam Lower right final slice view 6 Prepare apply outer tape seams securely taping clean bowl upside-down near corner table Flatten blimp Out no seam overlaps another Starting notch seam hold blimp down against bowl seam interior flap folded toward point contact bowl Beginning about 1 above notch apply3M #853-in Mylarsingle stick tape overtop seam Overlap both sides equally Dont allow interior flap become smaller larger seam progressively spreading apart pulling together Complete remaining seams same manner except gap 5 Resist urge inflate blimp Turn film Inside out actually right-side-out through tapeless gap seam Work slowly beginning far thest end Careful work pays off promise between strength weight clear transparent because cost minimum order quantities exotic colored metalized laminated versions couldnt justified small project such uncertain outcome material selected problem next forming proper shape size shape traditional blimp con tours seemed like good bet tail surface small hamper control backing up ease basic problem making closed container multiple compound curves flat material planned cut tail fins foam plastic meat trays tape place About easiest way forming generally paraboloid shape end blimp attach tapering gore pieces alongside another closed loop manner parachute technique surface contour would become pleasingly smoother number individual gores increased Clearly though some compromise called between aes thetics spending rest life fastening seams together Impatient see total concept worked settled having four gore pieces stretching nose tail tapered end As turned out ideal high temperature tolerance Mylar makes heat-welding seams critical procedure Addi tionally modelers have access heat-seaming equipment series experiments done perfect alternate method Special contact cement could brushed smoothly uniformly enough Tape looked promising construct compound curvature seams full-size form build over After much trial error pondering later technique described construction sec 64 Model Aviation 7 Fillertube made same material blimp Use pattern form cylinder Part way up base end ring tube Mylartape Below ring cut about eight equal flanges fold outward work surface lay double-sticktape square approx 2-in sides Holding tape circular set down base centered tape square Lay Mylar tape down across flange innermost edge barely covers gap either side near upright tube Trim taped flange area circular outline approx 2-in diameter Lift fillertubewith double-stick tape bottom S1 8 Inflate blimp last through tapeless gap vacuum cleaner hose attached discharge outlet Blimp now resembles rumpled boxy banana Sparingly tape over gap end seams come together Tape small square patch over end Position filler tube mid way between seams point behind lengthwise center blimp Tape down flange covering gaps Point modelers knife tube make X-cut skin inside Tapeless seam gap now can finished oft permanently Reinflate blimp twist filler tube tight secure rubberband Now best part Iron blimp over except tape MonoKote setting Make tail fins cabin attachment rings handling lines etc tape place Glue Velcro pads contact cement Paintailtaped seamswith two coats polyurethane thinned 50% Take vacation reacquaint yourself family friends outside world tion developed overcomes problems involved except onesuccess relates directly amount care patience exerts later next turned attention control system satisfy number criteria provide high degree maneuver ability several axes yet consume little power light weight course should simple rugged reliable directed thrust scheme potentially met requirements addition furnishing propulsion offered nearly direct movement desired direction sharp turning might have possible theoretically just thruster seemed easier positive use located near blimps center-ofgravity way energy would pointlessly wasted pitching rolling vehicle might look dramatic wouldnt effective maneuvering nearly stationary finally opted two thrusters either side cabin suspended beneath center gas containment bag could work col lectively same direction opposite direc tions differentially same direction different speeds both thrusters mounted ends cross tube could rotate about its longitudinal axis could pointed up down changing altitude boiled down three basic functions throttle including forward/reverse capability heading altitude felt possible achieve three control channels As thrusters themselves type quiet flexible enough electric power still left wide range possibilities easiest would have remove gears pair servos use motor/amplifier circuits mount propellers directly pinion shafts motors As Luther Hux subsequently demonstrated arrangement works quite well initially resisted appeal ingly simple solution two reasons conventional transmitter control arrangrnent possible use electronic mixing violating simple-to-duplicate rule skeptical power ungeared servo motors turn propellers adequately An alternative separate propulsion system RC system using latter solely control voltage polarity used former Modifying coreless armature motor appropriate gear reduction ratio proved frustrating repositioned pinion gear could made keep slipping its shaft being able locate other low-cost substitutes gears took chance 3volt Mabuchi RE-14 motors $150 4-in diameter rubber model propellers shoved onto shafts first glance propulsion motor control seemed demand nearly linear rpm change no steps requirement potentiometer series would have served nicely Continued page 120 March 1981 65 iimp caoin sop view snowing front back motor battery pack 100 mAh receiver battery dual multi-position rotary switches pushrod yokes brick-style receiver including elevation throttle servos heading servo Du-Bro mechanical mixer pushrods switches author shown compressing blimp remove airfrom inside maximum lifting ability much airas possible must removed blimp before inflating helium assisting Slights Xerox Training Center Ralph Heath logs some blimp time Lou gives instructions INTRODUCING TIle Arlleri RJL K61 R/C ENGINE RJL Industries now produces renowned engine formerly manufactured Kraft Systems Inc schnuerle ported 61 cubic inch engine provides easy starting high performance longevity Produced finest materials workmanship quality assurance youll proud have aircraft powered K61 FEATURES INCLUDE Schnuerle Ports Boost Port Double Ball Bearings Forged Alloy Piston & Con Rod Bushed Connecting Rod 0- ring Sealed Back Cover 16 HPat 15500 RPM SUGGESTED RETAIL $13995 Muffler Included Send Free Catalog Today R J L INDUSTRIES P0 Box 5654 Pasadena CA 91107 1831 Business Center Dr Duane CA 91010 wreckage ship strike Air Force vehicle parked field ship itself actually struck ground approximately 15 ft front vehicle however due planes high speed resultant wreckage immediately struck vehicle damaging actual hazard contributing factor hazard hazard am writing about cause ship going down planning stage demonstration re quested project officer radio operations 70 80 MHz range shut down demo fact accom plished base personnel However known club local TV stations area would using newer equipment cover event newer equipment being pressed use more TV stations commonly known live action remote TV Basically consists portable TV unit coupled high-powered transmitter make use live-coverage techniques Units transmitting frequencies actually adjacent own flying frequencies lies actual hazard transmit devices power output far exceeds power used own equipment adjacent frequency can bleed over enough point flying opera tions endangered case particular accident Clubs AMA demonstration teams should made aware potentially dangerous hazard soon possible avoid type accident occurring accident extremely close being disastrous aircraft airborne -second ship would have impacted upon car airborne another full second would have impacted upon USAF Thunderbird aircraft ship would have flying another direction loss control occurred could very well have flown crowd people estimated 3000-plus Luckily God willing case potential caution identifying hazard exercised organization giving demonstration result can disastrous mentioned above Sincerely yours s Michael S Lee President Luke Condors RC Club wind up months column item seen November 1980 issue British magazine Radio Control Models & Electronicsgives us food thought New Products RC Hobby section magazine write-up fail-safe device put Out Chromatronics mentioned previous column device neutralizes controls retards throttle either interference transmitter mal function occurs statement caught eye opening sentence mandatory conditions granting permit fly model aircraft excess 5-kg 11 lb weight provision fail-safe system stated mandates use fail-safe devices assume must some branch British government end question should consider using such fail-safe devices biggies show team models voluntary basis John Preston 7012 Elvira Court Falls Church VA 22042 Slow Year Blimp/Bruhn Continued page 65 However need reverse electrical polarity after tapering down power-off condition motor could advance opposite rotation Electronic throttles too costly heavy experiment mechanical arrangement reversing potenti ometer rotation conjunction switching polarity looked very complex Again taking expedient route hoped multiple position rotary switch could work enabled small enough stepped power changes direction pair inexpensive 12-position electronic switches modified provide two-step center off two-step reverse polarity independent control motor Actually moving switches appropriate position combinations required connecting control shafts through mechanical servo mixer blended throttle heading functions fact rotary switches positioned linear push-pull action meant travel limited less 1800 order avoid linkage jamming extremes throw Competing against commercial switch contacts necessitated about 1400 rotation cover full five-position sequence Without some compensation combination hard turn full throttle would drive pushrod other past jam limits avoid sliding pushrod/yoke arrangement added switch shafts Packaging sheet balsa cabin along three-channel radio system 24V 450 mAb drive-battery pack ballast made possibly compact serviceable simplest configuration assembly attached underneath gas bag hook end plus mating Velcro pads keep cabin shifting during thrust changes Modeling clay 120 Model Aviation 213/359-0016 Slope Squire Featured R/C SPORTSMAN SaraCen Featured RCM April 1976 Seville$6100 Featured MODEL AVIATION Apr 7 Winterhawk$57 Featured MODEL AVIATION May Hotrock Featured MODEL AVI Simitar 540 Featured RCM Oct 1978 COMPLETE PLANS WING CORE FIBERGLAS FUSELAGE PLYWOOD WING SHEETING CORE FILM WING SHEETING TAPE comes 14 X 60 yd roll $895 XHINGE$189/Pkg N EW EASY-MOUNT K&B 40 L ~dUIB vvrite 20825/z Roscoe Blvd Canoga Park CA 91306 BILL EVANS RIC AIRCRAFT Phone 213 709-0894 U IN Losing control can night mare wrong response given command can take its toll model nerves wallet Radio South know feel about hobby too avid RC enthusiasts nearly half century combined experience CONiRO modeling radio repair So avoid inflated repair costs undue service time Radio South fast economical inhouse radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control VISA 7 jrn Futaba_ 1925 E Creighton RoadPensacola FL 32504 904/478-6745 CUSTOM TUNED ENGINESGET ORGANIZEDWEVE EXPANDEDI COMPETITION ACCESSORIESHeresaseIof4sInrdyf4eSthahOIdSOOCSCALE DRAWINGSPHOTOS BOOKLETS Special GY 014 X 60 solid lines $295 ppd 4 yeas yon inoonte 0, II nagaZOUS Custom needle valves racing wheels4 MAG FILES $4950U quick fills fuel shut -a ffs & othersSend $495 pins $100 postag handling detailed brochure send 25 cents to0GM INDUSTRIESREPLA-TECI-I PO BOX 388-KiNTERNATIONAL Kustom Kraftsmanship Box 2699 Laguna HillsDOVER NH 03820CATALOGS $20048500 MC 5N818 HWY Calif 92653 Ph 714 830-5162voa 088008 97489 stuck around single landing wheel bottom cabin enabled blimp ballasted neutral buoyancy after inflation complete breathed deeply switched radio Construction Before beginning number things should clearly understood its large surface area very low mass blimp affected slightest air current includ ing too faint pilot sense Heating cooling system outlets convection currents outdoor operation impossible operating conditions unless equip blimp extremely high-thrust capability has kept away some otherwise prime sites enough say wasnt worth doubt test area first small helium balloon long string Second degree greater conventional projects success dependent amount patient attention given repetitious actions Helium escapes pathway offered including right through film material low rate course Seams must near perfect possible rapid loss buoyant gas will drastically shorten length operating time before removal ballast becomes necessary Keep mind youre tempted speed things up little after third seam Time spent being careful well worth later Finally particular design represents first generation stage development instructions precautions followed fairly closely have no doubt will have same level success have will able take real pride accomplishment Con siderable improvement should possible though Probe areas further development suggested end article own thing share rest us Rather give detailed fasten part part B instructions feel would helpful case provide illustrations supplemented notes comments blimps size relates load has support helps start determining weight radio system propulsion system other payload components including ballast Ballast important because will always helium gas leakage temperature/pressure atmospheric changes Some leeway adjust neutral buoyancy essential Dont forget include estimate weight gas bag weighed about 6 oz tail fins weight total ounces approximates ideal displacement cubic feet helium bag sea-level operaton practice some over-sizing must made allow impure gas higher elevation etc cabin pretty conventional once placement components has established Refer drawings photos further guidance Adjustment mechanical mixer linkage switch setup critical aspect assembly Two types switches diagramed Centralab 1002 usable modification isnt readily available modify Radio Shack 12-position shorting type no current interruption changing positions follows 1 Remove position detent ball socket 2 Carefully remove contact deck bottom switch 3 Use file divide inner contact ring two equal unconnected semi-circular segments 4 Remove switch shaft rotating contact disc switch mounting assembly 5 Make cannibalize another switch duplicate metal contact piece like already mounted rotating contact disc 6 Securely fasten new piece onto rotating contact disc would touch bottom deck contacts 1800 original contact piece 7 Adjust contact tension positive free reassemble switch elements Remove metal insert collar electric knob slide fully onto switch shaft tighten set-screw Make brass tin yoke solder onto collar Cut off switch shaft -in above collar Make solder pushrod retainer guide switch mounting washer Wire switch circuit test its operation thoroughly before installing cabin OK its time bite bullet make gas bag Thoroughly clean kitchen table top other very smooth hard Formica-like surface resolve stay until completion might take about week evenings following key points have common goal avoidance leakage paths First apply tape utmost care prevent bubbles gaps Second use smallest number separate pieces tape possible ie long piece rather two shorter pieces Third try avoid handling Mylar roughly folding sharply time Pinhole leaks will likely result Fourth keep clean Tape adheres best surface free grease dust release agent etc Wipe film areas apt taped later acetone before starting assembly Good luck Operation youre satisfied preliminary inflation checks using plain air detach cabin carefully work much air out bag possible Suck through fill tube really collapse flat Install balloon inflation valve onto compressed helium cyl inder prefer lay cylinder its side inflation nipple angled upward Get assis tant take precautions positively retain blimp inflate through fill tube half full cabin can reinstalled Continue inflation until just full overfilling reduces buoyancy increases gas leakage rate stresses seams Squeeze off fill tube near upper end twist lower portion tightly fold over upon itself loop rubberband repeatedly around secure Adjust ballast neutral buoyancy Eureka floats midair Charge batteries fully use Astro Flight 15-mm formula time receiver battery simple Amps X time charge March 1981 121 TLC RIC PRODUCTS Rt 1 Box 282 Prospect VA 23901 thoroughly depleted propulsion battery Opera tion sizes used averages 25 mm Its hard believe genuine excitement novice learning fly blimp confined space like living room Although weightless blimps inertia continues power off whatever direction headed last avoid probably harmless collision lamps plants candles other objects requires frantically reversing control maximum power Finesse called order control momen tum very limited thrust available tually getting hang vertical ascents descents spot landings become routine blimp can flown through hula hoop both backwards forwards calm air degree control seems practically unlimited Larger areas allow relaxed operation heading directional stability over long straight run marginal small tail fins Neverthe less theres always line turn sticks Just watch battery charge blimp small enough transported intact rear compact station wagon back seat folded down Going through rapid temperature changes outdoors indoors can dramatically change skin tension tem porarily Allow some time internal temper ature stabilize before readjusting inflation Future development concept begs modification havent yet time As example gas bag could made high-priced spread colored metalized film real impression seam-making technique should simpler Control system development can take directions electronic mixing geared servo motor thrusters different thruster location biggest opportunity may payloads airborne PA systems signs banners light-bulb changers etc Have ball Just sure pass along Summer Breeze Balloon/Hux Continued page 69 window does first convention filled up balloon nearby room started down hall auditorium entrance double door fixed center bar tightest squeeze yet applied bumper stickers over lock hinges protect balloon sharp edges People began wonder about strange placement campaign material pushed balloon through met several reporters barrage questions candidate came podium let balloon go flew up frontwhere people yet seen Previously described balloon candidate hadnt seen started opening remarks paused staring balloon banner pulled attention back what saying started over again told what expect guess just couldnt believe TV reporter asked us fly during next break film evening saw balloon few seconds announced political news next Imagine surprise have first public flight shown TV first time Lou saw balloon too Some conventions exciting othersnot programs flights buildings heavy air-conditioning equipment balloon pushed around quite lot series air-conditioning vents can play game full up full power under vent opposite between Occasionally someone would try help balloon low enough reach push like might give basketball would help give balloon little altitude would shoot ceiling. full down full power would bounce off ceiling. full up full power would scramble coming down though could hurt anyone settled imagine just sitting minding own business something blew ear type convention flying can cut flight time between recharge about 15 minutes still air could fly long hour lady puzzled transmitter took out hands What asked Its control balloon Im about crash replied calmly knowing balloon harmless After second word crash sank handed back like hot potato after disappeared crowd considered going big convention could just see delegates using big signs play badminton balloon After convention offered Bill Winter chance fly home planned way helium paid already As can read first Just Fun article quite reaciton bull-in-chinashop reaction bit surprise Con sidering room furniture 8-ft ceiling learn guess did seem lot handle could have tried gym Im sure would have enjoyed looks photo article Im sure much fun could thing have remind fliers inertialet off command long before get want go would make excellent training aid astronauts handling control jets weightless equipment Because ofour busy schedules balloon Lous blimp did fly together some time Chuck Thomas made arrangements us fly Saturday morning Xerox Train ing Center provide opportunity Dawn photograph two models pilots together Imagine will Xerox students getting up strolling through mezzanine way get morning cup coffeeand finding hot-air balloon blimp waltzing around building wide-eyed reactions lot fun guy asked unsure voice time go get cameraas thought wouldnt took eyes off thanks Ralph Heath escorting us four-hour photo session plans tell story building balloon problem some will 1 22 Model Aviation Fast realistic aerobatic kit features ABS wheelpants moulded canopy pre-bent wire Send $2500 plus $500 shipping to
Edition: Model Aviation - 1981/03
Page Numbers: 62, 63, 64, 65, 120, 121, 122
SI Year Blimp What type RC model has following characteristics 1 flies ultra-slow speeds 2 stable yet responsive maneuverable 3 durable harmless people objects might contact 4 produces little noise pollution 5 operable inexperi enced spectators points became criteria Slow Year Blimp developed merely beginning~ author says potentially sign ifi cant THE CLUB belong has recently faced common problem flying site uncertainty Neigh bors distance lease status have threatened flying field loss continuation club pursuing alternative sites mem bers recognized need some PR Support general public can invaluable seeking use park land other community property creating favorable impression dealings private landowners frequent method obtaining citizen appre ciation modeling demonstrate graphic ally through show team performances static displays shopping malls both help forming good opinion has certain limitations Show team performances often take place before audiences predisposed receptive area suited model flying Mall displays reach deeper broad spectrum public compete antique collectors Scout troops portrait artists myriad other attactions common areas shopping malls Slides movies help can fail capture special something sets building flying models apart other activities Somehow reasoned missing elementlive operationhad introduced otherwise static setting About time list criteria began article being drawn up response need early ads First Indoor RC Contest International Modeler Show 62 Model Aviation Slow Year Blimp cruises overhead Designer/Author Lou Bruhn Checking TV camera crew cabin Lightweight payload possibilities endless RUDDER 0PWR ARE 4 040OP YB INCH NOYR LAYEMFOAM COST OF 001 MYLARALTERNATE SHAPE TO OUTLINE .L-.MATCH APTERPOW00NRUMP 5 L___ --- ___ ____ _ _ ODEMIaL POLO LINE -00 NOT CUT-r POLO PRODUECS S LAYERS OLO LINE -OONOTCUT 5 IPOLD PAROWIC-ES LAYERS CD APPROTI 5 FORWARD OP COUNTER 0 E RIRSREAARR t-4I NZIif USE 0PUCE U-SECTION 5 OW PEWS P05101015 SAITCH IF YOUR SIPITOI IDES SOT RRTCW TESIOSS SIEWNI ULTOR WIRIWO TO 151101 FUNCTIONS GONDOLA BESIWN CAN RB ABSURD 10 SUIT RADIO LAYOUT OR ODORNAROCRI RE-UN/ TASTE IN DOSION RU OR SW CHES OUVIRO Tb-PUCE MOTORS SWLT oLOIJ-'fPUT RI LWENTER UP SWITCH PLATE IDAHORIONRUTUTIRUCESITER IIIIflu QDICYoW-TORN 4 11111SERVO All DRAM CO AR lASER IAdIZ SUNTANSOLDERI AVANTILIIII2L BRASSPROM WNSS 1111 OROTATE GI ON/APP SPEEDLIBSIWAP SERVO-11ffi--jOU BRUHN HEW WOO OVERRIDE YOKE TOTS IPTEIRO FOR SWITCHES ROWING THE TMPOLE TEWIOMLO TN THE SWITCH ETOES AlTO INPUT TO ROTATING CENTER PLATE THROUHI WIPER CONTACTS SLOW YEAR BLIMP appearing magazines addition heavierthan-air classes competition featured lighterthan-air LTA category inspiraton novelty coupled large doubt success fully satisfying preceding criteria conventional heavier-than-air technology led begin investigation LTA Consider ing possibility eventual success added requirement list construction should use non-toxic materials tech niques others might readily duplicate project Initial research showed LTA practic ally unknown model magazine readers aside handful isolated efforts spread over years Nearly involved rigid dirigible frameworks aerodynamic control surfaces soon ruled Out first features being too cumbersome transport time-consuming too easily damaged latter feature involved need constant forward motion complex extensive control linkages An alternative concept non-rigid blimp controlled directed thrust began take shape arrangement prospect exceptional maneuverability includ ing reverse direction turns place nearly vertical ascents descents buoyant lift chose forego slight advantage hydrogen total safety helium have never regretted decision challenge adequately restrict extremely small gas molecules escaping achieve usefully long period between ballast readjust ments way complicated automatic remotely-controlled ballast reduction systems could avoided clear key success LTA vehicle lay method constructing gas containment bag Research indicated instrumented atmospheric research balloons shrinks somewhat heateda feature made laminated layers polyester film would take particular significance later Moresuch DuPonts Mylar Polyester has over polyester mil 001 thick availbest gas retention factors film material t able transparent rolls 40 wide 50 ft long also has exceptional tensile strength less $10 Ichose gauge best com Dawn Hux holds Hula-Hoop blimp show its stuff Tricks like take practice careful control momentum PR possibilities led undertaking March 1981 63 WIRE 5009 OUPPON TAPED TO RORTOM OP RUMP 1100K 011 OORAOOLW 1 0 Note construction sequences shad ed lines representative joining tape 1 Cut piece film double length uninflated blimp Fold film three timesfirst across length twice lengthper layout drawing marker draw cut line along edge opposite final fold Holding layers alignment cut completely through along line Result will two identical double-gore pieces Clean both sides film acetone along future seams Position firstgore piece smooth hard clean surface Start 3M /2-in double-stick tape through notch between gores follow nearer edge curve lapping tape half onto film half onto work surface Roll tape down side pen avoid direct contact fingers Prevent gaps bubbles untaping redoing affected area 2 Carefully matching film edges exactly fold second gore over Onto first Start notch pay film down onto tape eliminating gaps bubbles occur Remove tape work surface along seam Youve done itl Now repeat other three notch seams checking fold will turn same way both ends gore Handle carefully seams dont come undone Result will two blimp halves 3 Lay both blimp halves flat top another untaped edges aligned Around mid-point edge mark longitudinal alignment same place film layers Set blimp half aside Spread untaped edges remaining blimp half apart bulk hanging off edge work surface tape down long seam edge Step 1 Small view shows slicethrough blimpif made now 4 Mate blimp halvestogetheralong just-taped seam making sure nose-to-nose inside-to-inside surface orientaton Start matching together alignment spots edge press film down Step 2 direction lJpperview shows slice stage Now remove surplus tape seam lift whole assembly clear complete remain ing long seam same manner Leave about I-ft tapeless gap arrows straight part final seam Lower right final slice view 6 Prepare apply outer tape seams securely taping clean bowl upside-down near corner table Flatten blimp Out no seam overlaps another Starting notch seam hold blimp down against bowl seam interior flap folded toward point contact bowl Beginning about 1 above notch apply3M #853-in Mylarsingle stick tape overtop seam Overlap both sides equally Dont allow interior flap become smaller larger seam progressively spreading apart pulling together Complete remaining seams same manner except gap 5 Resist urge inflate blimp Turn film Inside out actually right-side-out through tapeless gap seam Work slowly beginning far thest end Careful work pays off promise between strength weight clear transparent because cost minimum order quantities exotic colored metalized laminated versions couldnt justified small project such uncertain outcome material selected problem next forming proper shape size shape traditional blimp con tours seemed like good bet tail surface small hamper control backing up ease basic problem making closed container multiple compound curves flat material planned cut tail fins foam plastic meat trays tape place About easiest way forming generally paraboloid shape end blimp attach tapering gore pieces alongside another closed loop manner parachute technique surface contour would become pleasingly smoother number individual gores increased Clearly though some compromise called between aes thetics spending rest life fastening seams together Impatient see total concept worked settled having four gore pieces stretching nose tail tapered end As turned out ideal high temperature tolerance Mylar makes heat-welding seams critical procedure Addi tionally modelers have access heat-seaming equipment series experiments done perfect alternate method Special contact cement could brushed smoothly uniformly enough Tape looked promising construct compound curvature seams full-size form build over After much trial error pondering later technique described construction sec 64 Model Aviation 7 Fillertube made same material blimp Use pattern form cylinder Part way up base end ring tube Mylartape Below ring cut about eight equal flanges fold outward work surface lay double-sticktape square approx 2-in sides Holding tape circular set down base centered tape square Lay Mylar tape down across flange innermost edge barely covers gap either side near upright tube Trim taped flange area circular outline approx 2-in diameter Lift fillertubewith double-stick tape bottom S1 8 Inflate blimp last through tapeless gap vacuum cleaner hose attached discharge outlet Blimp now resembles rumpled boxy banana Sparingly tape over gap end seams come together Tape small square patch over end Position filler tube mid way between seams point behind lengthwise center blimp Tape down flange covering gaps Point modelers knife tube make X-cut skin inside Tapeless seam gap now can finished oft permanently Reinflate blimp twist filler tube tight secure rubberband Now best part Iron blimp over except tape MonoKote setting Make tail fins cabin attachment rings handling lines etc tape place Glue Velcro pads contact cement Paintailtaped seamswith two coats polyurethane thinned 50% Take vacation reacquaint yourself family friends outside world tion developed overcomes problems involved except onesuccess relates directly amount care patience exerts later next turned attention control system satisfy number criteria provide high degree maneuver ability several axes yet consume little power light weight course should simple rugged reliable directed thrust scheme potentially met requirements addition furnishing propulsion offered nearly direct movement desired direction sharp turning might have possible theoretically just thruster seemed easier positive use located near blimps center-ofgravity way energy would pointlessly wasted pitching rolling vehicle might look dramatic wouldnt effective maneuvering nearly stationary finally opted two thrusters either side cabin suspended beneath center gas containment bag could work col lectively same direction opposite direc tions differentially same direction different speeds both thrusters mounted ends cross tube could rotate about its longitudinal axis could pointed up down changing altitude boiled down three basic functions throttle including forward/reverse capability heading altitude felt possible achieve three control channels As thrusters themselves type quiet flexible enough electric power still left wide range possibilities easiest would have remove gears pair servos use motor/amplifier circuits mount propellers directly pinion shafts motors As Luther Hux subsequently demonstrated arrangement works quite well initially resisted appeal ingly simple solution two reasons conventional transmitter control arrangrnent possible use electronic mixing violating simple-to-duplicate rule skeptical power ungeared servo motors turn propellers adequately An alternative separate propulsion system RC system using latter solely control voltage polarity used former Modifying coreless armature motor appropriate gear reduction ratio proved frustrating repositioned pinion gear could made keep slipping its shaft being able locate other low-cost substitutes gears took chance 3volt Mabuchi RE-14 motors $150 4-in diameter rubber model propellers shoved onto shafts first glance propulsion motor control seemed demand nearly linear rpm change no steps requirement potentiometer series would have served nicely Continued page 120 March 1981 65 iimp caoin sop view snowing front back motor battery pack 100 mAh receiver battery dual multi-position rotary switches pushrod yokes brick-style receiver including elevation throttle servos heading servo Du-Bro mechanical mixer pushrods switches author shown compressing blimp remove airfrom inside maximum lifting ability much airas possible must removed blimp before inflating helium assisting Slights Xerox Training Center Ralph Heath logs some blimp time Lou gives instructions INTRODUCING TIle Arlleri RJL K61 R/C ENGINE RJL Industries now produces renowned engine formerly manufactured Kraft Systems Inc schnuerle ported 61 cubic inch engine provides easy starting high performance longevity Produced finest materials workmanship quality assurance youll proud have aircraft powered K61 FEATURES INCLUDE Schnuerle Ports Boost Port Double Ball Bearings Forged Alloy Piston & Con Rod Bushed Connecting Rod 0- ring Sealed Back Cover 16 HPat 15500 RPM SUGGESTED RETAIL $13995 Muffler Included Send Free Catalog Today R J L INDUSTRIES P0 Box 5654 Pasadena CA 91107 1831 Business Center Dr Duane CA 91010 wreckage ship strike Air Force vehicle parked field ship itself actually struck ground approximately 15 ft front vehicle however due planes high speed resultant wreckage immediately struck vehicle damaging actual hazard contributing factor hazard hazard am writing about cause ship going down planning stage demonstration re quested project officer radio operations 70 80 MHz range shut down demo fact accom plished base personnel However known club local TV stations area would using newer equipment cover event newer equipment being pressed use more TV stations commonly known live action remote TV Basically consists portable TV unit coupled high-powered transmitter make use live-coverage techniques Units transmitting frequencies actually adjacent own flying frequencies lies actual hazard transmit devices power output far exceeds power used own equipment adjacent frequency can bleed over enough point flying opera tions endangered case particular accident Clubs AMA demonstration teams should made aware potentially dangerous hazard soon possible avoid type accident occurring accident extremely close being disastrous aircraft airborne -second ship would have impacted upon car airborne another full second would have impacted upon USAF Thunderbird aircraft ship would have flying another direction loss control occurred could very well have flown crowd people estimated 3000-plus Luckily God willing case potential caution identifying hazard exercised organization giving demonstration result can disastrous mentioned above Sincerely yours s Michael S Lee President Luke Condors RC Club wind up months column item seen November 1980 issue British magazine Radio Control Models & Electronicsgives us food thought New Products RC Hobby section magazine write-up fail-safe device put Out Chromatronics mentioned previous column device neutralizes controls retards throttle either interference transmitter mal function occurs statement caught eye opening sentence mandatory conditions granting permit fly model aircraft excess 5-kg 11 lb weight provision fail-safe system stated mandates use fail-safe devices assume must some branch British government end question should consider using such fail-safe devices biggies show team models voluntary basis John Preston 7012 Elvira Court Falls Church VA 22042 Slow Year Blimp/Bruhn Continued page 65 However need reverse electrical polarity after tapering down power-off condition motor could advance opposite rotation Electronic throttles too costly heavy experiment mechanical arrangement reversing potenti ometer rotation conjunction switching polarity looked very complex Again taking expedient route hoped multiple position rotary switch could work enabled small enough stepped power changes direction pair inexpensive 12-position electronic switches modified provide two-step center off two-step reverse polarity independent control motor Actually moving switches appropriate position combinations required connecting control shafts through mechanical servo mixer blended throttle heading functions fact rotary switches positioned linear push-pull action meant travel limited less 1800 order avoid linkage jamming extremes throw Competing against commercial switch contacts necessitated about 1400 rotation cover full five-position sequence Without some compensation combination hard turn full throttle would drive pushrod other past jam limits avoid sliding pushrod/yoke arrangement added switch shafts Packaging sheet balsa cabin along three-channel radio system 24V 450 mAb drive-battery pack ballast made possibly compact serviceable simplest configuration assembly attached underneath gas bag hook end plus mating Velcro pads keep cabin shifting during thrust changes Modeling clay 120 Model Aviation 213/359-0016 Slope Squire Featured R/C SPORTSMAN SaraCen Featured RCM April 1976 Seville$6100 Featured MODEL AVIATION Apr 7 Winterhawk$57 Featured MODEL AVIATION May Hotrock Featured MODEL AVI Simitar 540 Featured RCM Oct 1978 COMPLETE PLANS WING CORE FIBERGLAS FUSELAGE PLYWOOD WING SHEETING CORE FILM WING SHEETING TAPE comes 14 X 60 yd roll $895 XHINGE$189/Pkg N EW EASY-MOUNT K&B 40 L ~dUIB vvrite 20825/z Roscoe Blvd Canoga Park CA 91306 BILL EVANS RIC AIRCRAFT Phone 213 709-0894 U IN Losing control can night mare wrong response given command can take its toll model nerves wallet Radio South know feel about hobby too avid RC enthusiasts nearly half century combined experience CONiRO modeling radio repair So avoid inflated repair costs undue service time Radio South fast economical inhouse radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control VISA 7 jrn Futaba_ 1925 E Creighton RoadPensacola FL 32504 904/478-6745 CUSTOM TUNED ENGINESGET ORGANIZEDWEVE EXPANDEDI COMPETITION ACCESSORIESHeresaseIof4sInrdyf4eSthahOIdSOOCSCALE DRAWINGSPHOTOS BOOKLETS Special GY 014 X 60 solid lines $295 ppd 4 yeas yon inoonte 0, II nagaZOUS Custom needle valves racing wheels4 MAG FILES $4950U quick fills fuel shut -a ffs & othersSend $495 pins $100 postag handling detailed brochure send 25 cents to0GM INDUSTRIESREPLA-TECI-I PO BOX 388-KiNTERNATIONAL Kustom Kraftsmanship Box 2699 Laguna HillsDOVER NH 03820CATALOGS $20048500 MC 5N818 HWY Calif 92653 Ph 714 830-5162voa 088008 97489 stuck around single landing wheel bottom cabin enabled blimp ballasted neutral buoyancy after inflation complete breathed deeply switched radio Construction Before beginning number things should clearly understood its large surface area very low mass blimp affected slightest air current includ ing too faint pilot sense Heating cooling system outlets convection currents outdoor operation impossible operating conditions unless equip blimp extremely high-thrust capability has kept away some otherwise prime sites enough say wasnt worth doubt test area first small helium balloon long string Second degree greater conventional projects success dependent amount patient attention given repetitious actions Helium escapes pathway offered including right through film material low rate course Seams must near perfect possible rapid loss buoyant gas will drastically shorten length operating time before removal ballast becomes necessary Keep mind youre tempted speed things up little after third seam Time spent being careful well worth later Finally particular design represents first generation stage development instructions precautions followed fairly closely have no doubt will have same level success have will able take real pride accomplishment Con siderable improvement should possible though Probe areas further development suggested end article own thing share rest us Rather give detailed fasten part part B instructions feel would helpful case provide illustrations supplemented notes comments blimps size relates load has support helps start determining weight radio system propulsion system other payload components including ballast Ballast important because will always helium gas leakage temperature/pressure atmospheric changes Some leeway adjust neutral buoyancy essential Dont forget include estimate weight gas bag weighed about 6 oz tail fins weight total ounces approximates ideal displacement cubic feet helium bag sea-level operaton practice some over-sizing must made allow impure gas higher elevation etc cabin pretty conventional once placement components has established Refer drawings photos further guidance Adjustment mechanical mixer linkage switch setup critical aspect assembly Two types switches diagramed Centralab 1002 usable modification isnt readily available modify Radio Shack 12-position shorting type no current interruption changing positions follows 1 Remove position detent ball socket 2 Carefully remove contact deck bottom switch 3 Use file divide inner contact ring two equal unconnected semi-circular segments 4 Remove switch shaft rotating contact disc switch mounting assembly 5 Make cannibalize another switch duplicate metal contact piece like already mounted rotating contact disc 6 Securely fasten new piece onto rotating contact disc would touch bottom deck contacts 1800 original contact piece 7 Adjust contact tension positive free reassemble switch elements Remove metal insert collar electric knob slide fully onto switch shaft tighten set-screw Make brass tin yoke solder onto collar Cut off switch shaft -in above collar Make solder pushrod retainer guide switch mounting washer Wire switch circuit test its operation thoroughly before installing cabin OK its time bite bullet make gas bag Thoroughly clean kitchen table top other very smooth hard Formica-like surface resolve stay until completion might take about week evenings following key points have common goal avoidance leakage paths First apply tape utmost care prevent bubbles gaps Second use smallest number separate pieces tape possible ie long piece rather two shorter pieces Third try avoid handling Mylar roughly folding sharply time Pinhole leaks will likely result Fourth keep clean Tape adheres best surface free grease dust release agent etc Wipe film areas apt taped later acetone before starting assembly Good luck Operation youre satisfied preliminary inflation checks using plain air detach cabin carefully work much air out bag possible Suck through fill tube really collapse flat Install balloon inflation valve onto compressed helium cyl inder prefer lay cylinder its side inflation nipple angled upward Get assis tant take precautions positively retain blimp inflate through fill tube half full cabin can reinstalled Continue inflation until just full overfilling reduces buoyancy increases gas leakage rate stresses seams Squeeze off fill tube near upper end twist lower portion tightly fold over upon itself loop rubberband repeatedly around secure Adjust ballast neutral buoyancy Eureka floats midair Charge batteries fully use Astro Flight 15-mm formula time receiver battery simple Amps X time charge March 1981 121 TLC RIC PRODUCTS Rt 1 Box 282 Prospect VA 23901 thoroughly depleted propulsion battery Opera tion sizes used averages 25 mm Its hard believe genuine excitement novice learning fly blimp confined space like living room Although weightless blimps inertia continues power off whatever direction headed last avoid probably harmless collision lamps plants candles other objects requires frantically reversing control maximum power Finesse called order control momen tum very limited thrust available tually getting hang vertical ascents descents spot landings become routine blimp can flown through hula hoop both backwards forwards calm air degree control seems practically unlimited Larger areas allow relaxed operation heading directional stability over long straight run marginal small tail fins Neverthe less theres always line turn sticks Just watch battery charge blimp small enough transported intact rear compact station wagon back seat folded down Going through rapid temperature changes outdoors indoors can dramatically change skin tension tem porarily Allow some time internal temper ature stabilize before readjusting inflation Future development concept begs modification havent yet time As example gas bag could made high-priced spread colored metalized film real impression seam-making technique should simpler Control system development can take directions electronic mixing geared servo motor thrusters different thruster location biggest opportunity may payloads airborne PA systems signs banners light-bulb changers etc Have ball Just sure pass along Summer Breeze Balloon/Hux Continued page 69 window does first convention filled up balloon nearby room started down hall auditorium entrance double door fixed center bar tightest squeeze yet applied bumper stickers over lock hinges protect balloon sharp edges People began wonder about strange placement campaign material pushed balloon through met several reporters barrage questions candidate came podium let balloon go flew up frontwhere people yet seen Previously described balloon candidate hadnt seen started opening remarks paused staring balloon banner pulled attention back what saying started over again told what expect guess just couldnt believe TV reporter asked us fly during next break film evening saw balloon few seconds announced political news next Imagine surprise have first public flight shown TV first time Lou saw balloon too Some conventions exciting othersnot programs flights buildings heavy air-conditioning equipment balloon pushed around quite lot series air-conditioning vents can play game full up full power under vent opposite between Occasionally someone would try help balloon low enough reach push like might give basketball would help give balloon little altitude would shoot ceiling. full down full power would bounce off ceiling. full up full power would scramble coming down though could hurt anyone settled imagine just sitting minding own business something blew ear type convention flying can cut flight time between recharge about 15 minutes still air could fly long hour lady puzzled transmitter took out hands What asked Its control balloon Im about crash replied calmly knowing balloon harmless After second word crash sank handed back like hot potato after disappeared crowd considered going big convention could just see delegates using big signs play badminton balloon After convention offered Bill Winter chance fly home planned way helium paid already As can read first Just Fun article quite reaciton bull-in-chinashop reaction bit surprise Con sidering room furniture 8-ft ceiling learn guess did seem lot handle could have tried gym Im sure would have enjoyed looks photo article Im sure much fun could thing have remind fliers inertialet off command long before get want go would make excellent training aid astronauts handling control jets weightless equipment Because ofour busy schedules balloon Lous blimp did fly together some time Chuck Thomas made arrangements us fly Saturday morning Xerox Train ing Center provide opportunity Dawn photograph two models pilots together Imagine will Xerox students getting up strolling through mezzanine way get morning cup coffeeand finding hot-air balloon blimp waltzing around building wide-eyed reactions lot fun guy asked unsure voice time go get cameraas thought wouldnt took eyes off thanks Ralph Heath escorting us four-hour photo session plans tell story building balloon problem some will 1 22 Model Aviation Fast realistic aerobatic kit features ABS wheelpants moulded canopy pre-bent wire Send $2500 plus $500 shipping to