Radio Control: Soaring

RADIO CONTROL SOARING MORE ON THE FALCON 880/ SD7037 Ernie Barter head guy VMC Flight manufacturer Model 20 retriever sent letter photos new Falcon 880 February column talked about flying Mark Allens 880 SD7037 airfoil ship weighed 59 ounces flew great mentioned seemed little too light Since no provision adding ballast didnt try greater weights Naturally very interested hear comments Ernie Enjoyed article re Falcon 880/ SD7037 am just now getting used 880 59 ounces youre correct too light have 7037 airfoil pre-sheeted Elite Lite 59 ounces floats have ballasted 64 69 ounces both weights different airplane have testing think 64-ounce weight about right although no noticeable difference between 64 69 for-what-its-worth department built Falcon rudder stab servo tail Rudder spar/sub spar fin stiffeners taped place fin gets very rigid configuration required twoounce nose ballast cant imagine building sixth servo rudder linkage staying within 59 ounces Handling superb rudder thanks aileron differential Thermal turns just fine slow speed approach turns flaps/crow problem thanks sharing findings Ernie Ive seen Electrics elevator servo fin first time Ive heard done glider Electrics course have ample built-in nose weight motor servo tail plus far balancing concerned Ernie must have taken cue F3E Electrics because get along rudders too Gliders always need added nose weight usual procedure put heavy stuff battery servos far forward possible elevator servo fin directly coupled stab linkage slop should eliminated hand launchers coming Handlaunched RC gliders HLG relatively small part hobby theyre probably fastest growing segment Youll see quite few new HLG kits coming out year appeal obvious inexpensive quick put together can tossed around small fields lunch hour also teach lot about flying low-level lift Bud Black Soaring League North Texas sent rundown seventh annual Southwest HLG contest will held July 11 Buds description contest might just encourage other clubs give HLG events try increased interest Class sailplanes San Antonio Austin Houston Tulsa should able exceed goal 30 contestants will fly 10minute Time Slot using hand launch optional Zip Start Also nine-minute AddEm-Up using 1A-inch rubber Dynaflite Up Starts four-minute max per flight developed Zip Start 10 feet 1R-inch rubber 20 feet 20-pound monofilament three pounds pull give weak arm no captive gorillas fighting chance against pilots strong arms doesnt get high launch gorilla does up odds bit Dynaflite rubber seems work better tubing weve tried think weve tried info Southwest HLG contest call Henry Bostick 214 279-8337 like SLNTs Zip Start idea arm too old weak get half height younger guys artificial assistance welcome course problem Zip Start spiked ground youre stuck launch location normal scene HLG contest pilots running over field attempting throw gliders lift marked other gliders low altitudes dealing thermals tend small trick launch directly brings up question Would legal have ones helper hold rubber end Zip Start pilot helper could trot over toward gaggle use Zip Start shoot right lift talking about three pounds pull holding rubber would no problem helper Heres another idea Someone should build RC version famous Jim Walker American Junior Interceptor benefit younger readers dont know about Jim Walker ingenious inventions Interceptor little all-balsa glider has wings fold back alongside fuselage much like WW II Grumman carrier planes eg Wildcat Hellcat Avenger shot air little catapultjust hefty rubber band 82 Model Aviation Blacks group photo contestants 1992 Southwest Hand Launch contest 93 event will July 30 pilots expected compete Tail end Ernie Barters Falcon 880 Elevator servo mounted bottom fin fin post taped place allow access New JR Charge Switch incorporates receptacle charge plug ni unarge wiicn mounted authors Saturn 29T currently under construction Interested Soaring Electric Flight Great So Are Northeast Sailplane Products carry comprehensive line silent flight prod ucts industry sell R/C Sail planes Electrics related accessories reference features hundreds products doz ens informative articles technical infor mation great sport RIO silent flight can meet needs abilities beginner expert dedicated pro viding personal customer service Check out NSP..youlI glad did Sailplane Products 1993 RC Soaring Electric Reference Northeast N N N N N Price S5 Northeast Sailplane Products16 Kirby Lane Wilton VT 05495 comprehensive reference Radio Control Soaring Electric Flight 802 658-9482 end short stick got Interceptor up about 30 feet top launch gliders speed dropped suffi ciently wings popped open small rubber band flew pretty well no-a iifoil glider Until couple years ago American Junior Aircraft Company Portland Oregon advertised A-J Interceptor Model Builder magazine price $695 RTF ready fly Ubuild kit $495 last bought 75 centsbut about 1946 JR Remote Control has new productsa new servo new airborne switchthat think will interest sailpianers new JR Switch terrific idea cord airborne pack plugs directly thus eliminating pigtail wire used regular switches wire always seems get lost under servo tray 057 x 13 x 076 inches Switch about twice size regular switches probably wont fit smaller gliders Retail list $1995 new JR servo No 3321 designed wing-mounted aileron flap operation high-quality servo coreless motor dual ball bearings Its dimensions 058 x 130 x 130 inches almost exactly same size Airtronics 141 3321 lighter thinner wing installations excellent choice JR 341 microservo 050 inches thick has superstrong nylon gears JR 3321 lists $8995 comes mounting lugs horizontal vertical mounting Whats unique about horizontal mounts molded center case intelligent innovation because allows use servo either left right wing Id better explain Standard procedure mount servos wings output shafts pointing toward wing tips first servo US market designed specifically wing mounting Airtronics 141 has horizontal mounting lugs both top bottom case normal installation need cut lugs off side other plus vertical lugs So wind up left- righthanded servos too big deal except means carrying twice spare wing servos field box Another excellent feature 3321 completely new extra-strong plastic gear train near-zero backlashand claimed zero deadband JR calls gear system Mega-Mesh Output gears have nearly double surface area similar size servos 3321 has good torque 598 ounce-inches moderate speed sound good too Understanding JR Servos new 28page booklet lists complete specs JR servos gives detailed descriptions Its available free Horizon Hobby Distributors write 4105 Fieldstone Rd Champaign IL 61821 call 217 355-0022 booklet says JR engineers took objective having virtually nonstrippable gear train system strong will probably pull servo its mounting block before losing gear Tips Tips July 1992 column reprinted piece Eastern Soaring Leagues newsletter ESL News edited Mike Lachowski piece called Tips Tips contained short explanation Michael Selig response question Mike put him about ailerons tipped-up wing tips Californian Blame Beron-Rawdon saw sent letter pointing out explanation incomplete sent Blames letter Michael asking comments Michael responded yes original ESL News piece addressed initial part turn steady-state thermal circling conditions think youll find aerodynamics theory interesting Im going reprint original piece Mike Lachowski plus follow-up letters Blame Michael Tips Tips Michael Selig have exchanged some notes observations aileron tip configurations various designs observation tip aileron placement Two-Meter June1993 83 Welcome world NSP first open unique reference will awe number quality products have Also ordering us easy fun because help step way order reference mail $700 $5 plus $2 s&h NSF Well ship reference via express mail arent completely satisfied simply send back prompt courteous refund Northeast Sailplane Products 16 Kirby Lane Williston Vermont 05495 ships Number two ships wing aile rons few inches tip bent tips upward Handling greatly improved Michael Seligs explanation follows Thanks note observation tip stall characteristics relation ailerons Mark Allen has found out same thing Maybe can explain Consider right turn Right aileron goes up left down low-speed wing right wing right turn sees downwash tiplet aileron will delay tip stall right wing extend ailerons way tip wont have favorable effect Right urn Iue upwah rnMdrnflSl NspeedUplot W-SPdP Left WingRight Wing Blame Beron-Rawdons letter read interest lead item column July MA seems something has lost translation Michael Selig Mike Lachowski description effect ailerons lift distribution Ci coefficient liftBB distribution wing tip area makes sense basic assumption direction aileron deflection mistaken example shown plane right thermal circle opposed right roll maneuver both wings going same speed As pointed out right wing going slowly since inside circle covering less distance per circle plane steady-state bank rolling means net roll moment due wings must zerothe left wing balances right wing Since right wing flying slowly left must pulling higher lift coefficient left wing Since aileron ships have very little dihedral way achieve greater lift coefficient droop inboard aileron andlor reflex outboard aileron exactly opposite what described article figure Moving end aileron inboard few inches still may help tip stall problem however Drooping aileron increases local effective angle attack local camber Leaving tip area unchanged effectively gives washout inboard tip reducing local lift coefficient tendency stall sharp discontinuity lift distribution end aileron however flow tends out decreasing lift near end aileron increasing lift just outboard aileron net effect still washout though purpose value bending tip panel aileron up fairly extreme dihedral angle very unclear may desirable increase overall dihedral plane increase spiral sta bility would efficient bending much wing up much less Furthermore bending just small tip area up lot likely cause tip stalls tip has lot dihedral its angle attack will strongly affected yaw angle aircraft tends yaw outboard circling vertical stabilizer lines up local curved flow outboard yaw increases angle attack tip panel increasing chance tip stall really wanted inhibit tip stall would leave tip dihedral zero perhaps bend down bit outboard yaw reduced angle attack subject cutting back aileron tip location should pointed out will reduce roll rate plain tip areas will damp roll motion regardless aileron deflection achieve equivalent roll rate remaining aileron throw will have increased inboard edge aileron extended inboard reducing potential flap area may easier envision effect aileron arrangement drawing analogy dihedral arrangement dihedral angle scheme rudder-elevator airplanes analogous chord location ailerons aileron ship instance standard outboard ailerons equivalent three-panel polyhedral wing flat center section Full-span ailerons equivalent V-dihedral ailerons cut back tip equivalent bending last few inches tip panels flat Model Aviation articles dihedral August November 1988 spiral stability September October 1990 address number points greater detail Michael Seligs letter Yes something lost translation tiplet reduces tip stall tendency placement aileron Aside Blame makes good point drawing shows right turn inboard aileron right wing aileron goes up initiate turn situation applies turn initiated period time inboard aileron produces favorable downwash alleviates tendency tip stall argument however does hold once glider steady-state circling flight situation becomes necessary hold opposite aileron prevent over-bank tendency right rudder maintain coordinated flight explanation having ailerons stop short tips best tip stall prevention steady-state turn glider circling flight inboard wing ie wing inside circle must produce higher lift coefficient outboard wing 84 Model Aviation products take maintenance building new heights Custom Cradles Feature Custom molded gray tubing--no ugiy fittings Special neoprene loam--impervious fuel oil Lo Boy Standard Large X-Large Tall Boy Standard Large X-Large N NEW Legz od 0 box s de NEW Radio Rack use folded position Call today order 1 -800-CRADLE-O 272-3530 Folds easy storage Custom design built last Ready use--no building Easily adjusted La Boy Custom Cradles Lo Boy Standard--i 0 tail 22 long 3 5 wide fuselage- 90 Lo Boy Large--i 4 tall 26 long 5to 8 wide fuselage -$2590 Lo Boy X-Large--1 6 tall 28 long 8 12 wide fuselage 2890 Tall Boy Custom Cradles Tall Boy Standard--32 tall 22 long 3to 5 wide fuselage 490 Tail Boy Large-28 tall 26 long 5to8 wide fuselage $3690 Tall Boy X-Large--26 tall 28 long 8 12 wide fuselage-----$3890 AccessorIes Legz--1 8 tall 18 wide hardware included fits boxes----$2990 Radio Rack--it folds compact protects radio home field 0 prIces Include shIppIng handlIng Send check money order today shIp UPS daIly o9Ws aatm zodaes 3177 East Fail Lowell Road SI Tucson Miona 85716 explained Blames letter glider made stall inboard wing will stall first since must operate higher lift coefficient Specifically stall will first take place over inboard aileron since doing work generate lift aileron extended tip tip stall will occur aileron stalls stalled portion wing moved toward fuselage stall no longer characterized tip stall can achieved moving ailerons toward fuselage since again part wing stalls first Thanks guys Im sure everyone now has better understanding design glider wings Just pass along some personal news Michael reports now married assistant professor aeronautical astronautical engineering University Illinois Champaign received under graduate degree U says Its nice back especially professor Ive heard Michael doing some design consulting work couple new gliders tremendous resource its exciting know continuing work model glider field Old-time sailplaners will remember Blame Beron-Rawdon designer Mirage 112-inch-span glider mid 1970s crewed Paul MacCreadys Gossamer Albatross senior member AeroVironment design team Solar Challenger Team Manager 1985 US F3B Team Blame now configuration designer McDonnell Douglas Long Beach Cal ifornia doesnt compete much days placed respectable 16th Visalia last October Aspiring sailplane designers wanting learn about dihedral spiral stability would well look up s series articles Model Aviation August through November 1988 September October 1990 respectively highly recommended Since aerodynamics kick thought would good spot print another interesting note Michael Selig Last year short article written Fritz Bien Connecticut made circuit club newsletters Fritz codesigner Dwight Holley 1981 F3B World Champions Gobbler last allwood glider win World Championship Anyway Fritzs point currently popular 5D7037 airfoil showed much lower drag older S3021 100000 Reynolds number Princeton tests reported Soartech #8 similarly shaped Fritz says Both airfoils fall right top other within single swipe sanding block dont know build accurately separate character istics two airfoils used airplane flapperonswhich never neutral position anyway Besides difference trailing edge two airfoils would 0008 less deviation airfoil Harley Michaelis made 5D7037 section wait Thats airfoil Harley made right approach having great drag polar lOOK Re range main difference between Michaelis airfoil S3021 5D7037 entry angle front top surface shallower 0030 inches out 12-inch chord would require lot sanding to average tA6inch sheeting other hand usual sag between ribs should produce excellent effect socalled super-airfoil moral story use actual 5D7037 PT airfoil original 5D7037 want duplicate wind tunnel tests duplicate airfoils vastly superior ones using fly wind tunnel field asked Michael Selig about Fritzs conclusions said think main content piece Fritz Bien finds difficult cosporison Michaehsu 5D7037 S3021 comparison Michoeliss 5D7037 5D7037 less trailing edge thickness of wings As happened Harley Michaelis well-known sailplane designer competitor Walla Walla Washington built 5D7037 wind tunnel wing model used Princeton Selig-Donovan-Fraser tests Fritz continues Using late David Frasers notation mean deviation between believe slight variations airfoil shape can lead significant changes performance may hard believe true reasons find airfoil design problem intriguing would agree Fritz wishes obtain performance shown Soartech #8 Continued page 57 June 1993 85 Legz Tail Boy have everything Call free brochure Dealer Inquires welcome UU-NO MORE WORRY ABOUT CRITICAL RADIO PLUGS BECOMING DISCONNECTED WHEN YOU USE THIS NEW WELL DESIGNED SAFETY ITEM PI Safety Ass U PROVIDES POSITIVE SECURELY LOCKED CONNECTION SNAP ACTION PROVIDES FOR OUICK AND EASY INSTALLATION AND REMOVAL OF THE SAFETY CLIP WHEN YOU UNPLUG THE CLIP CAN BE INSTALLED ON THE LARGER PORTION OF THE PLUG FOR SAFEKEEPING FOR USE ON PLANES HELICOPTERS CARS AND BOATS CONSTRUCTED OF NYLON FOR LIFETIME USE THREE SAFETY CLIPS SUPPLIED PER PACKAGE FOR USE ON BATTERY PACK AND AILERON PLUGS OR OTHER EXTENSIONS PACKAGE PRICE 9 SEE YOUR LOCAL HOBBY DEALER SAFETY CLIPS AVAILABLE FOR THE FOLLOWING PLUGS Airtronics Aristocraft 5 Slim Cirrus C Cox Futaba J Hitec JR Kyosho BUY PACK TO GUARD AGAINST IMPACT Parsons Pmducts PO Box 82038 Baton Rouge LA 70884-2038 Gee Bees turn Ofl write Henry Haffke RR #1 Box 22 Londonderry VT 05148 documentation information out just have tap right source giant will scale perfection Ive included photograph Ron Weisss latest Giant Scale gem Its 1/3-scale Fokker DVIII Hying Razor wingspan nine feet three inches 1650 square-inch area fuselage 74 inches long model weighs 30 pounds Kioritz 24cubic-inch engine powers Ron searched long hard authentic set threeviews Fokker found World War Aeroplanes Heinz J Nowarra s efforts Harleyford Publications model pictured has flying since 1985 Ron reports closely duplicates originals flight characteristics bird bit antsy landings like other models WW aircraft handles like big Cub air anyone interested duplicating big DVIII Ron offers drawings Contact Ron Weiss 20 Linda P1 Huntington NY 11743and include large SASE Ron also offers definitive 1A-scale plans set 1930 Fleet 2 biplane Ive seen Fleet drawings theyre superb columnists get gray hair addition fine letters receive readers get manner news releases manufacturers model-related products latter 99% great value keeping informed whats available make modelers life easier remaining percent obtuse confuse heck out rational person Got latter about week ago What amounted instruction sheet rather complex device Although named device indicated its price just functioned almost complete mystery news release soon found home proverbial File 13 circular oneand noted several new gray tendrils temples Make em big fly em big Back next month oaringlBlakeslee Continued page 85 actual test model coordinates PT designation should used will add probably necessary average error greater 0004 inches Reference effect made page 52 90 Soartech #8 food thought what would-be competitors constantly searching latest hot airfoil now told probably cant build wing performs book says Some builders may find no-suchthing-as-perfect concept depressing submit however can actually add fun building flying comparing model sailplanes shops carefully cut ribs make templates cut foam cores bag fiberglass obechi skins sand out imperfections thinking little change here.a tweak there.this glider could turn out being demon supership live hopes hitting jackpot Soartech #9 available Soartech #8 Airfoils Low Speeds popular has delayed publication next number Number 9 now available $8 postage paid US Included #9 following papers Use Wind Tunnel Data Design RC Contest Model Sailplanes Martin Simons Static Longitudinal Stability CROCCO Method Ferdi Gale Fear Flying Wing Noel Falconer Wing Load Computation Max Chernoff What Can Learned Paper Airplanes Hewitt Phillips Built-In Sheeting Dennis Oglesby Publisher Herk Stokely says has enough material hand put out Soartech #10 fairly soon will 200 pages long will feature photo essay Martin Bamert covering aspects creation completely composite model Continued page 90 BPLGAIN ION IDOL ing Control can nightmare 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 modeling radio repair So avoid inflated repair Costs undue service time Radio South fast economical in-house radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control D Fuataba KRAFT CN jAIRThMICS 5524 N Palafox Pensacola FL 32503 repair information 904 434-0909 1-800-962-7802 Toll Free Order Line Orders Only Please) June 1993 87 New Kits 1993 Viper sleek new design outstanding maneuverability stability track like arrow Viper 40 plus size engines motors emphasis proper construction minimize flying weight optimize performance design utilizes fully symmetrical tapered airfoil has ample room retracts fuselage can easily hold power batteries required electric flight desired VIPER Wingspan 60 Wing Area 620 sq Airfoil symmetrical #DS 016 basic kit kit features formed landing gear complete hardware package canopy selected die machine cut balsa plywood spruce hardwood parts Also included complete fulisize rolled plans photo illustrated instruction manual new high performance sailplane designed electric powered flight new two meter span Vengence can launch speck size less minute 075 Hyperthrust II motor seven cells kit has designed rudder elevator motor operation utilizes fuselage designed large enough accommodate 12 cell 1200 mAh larger packs including taller cell batteries design also includes hatch bottom facilitate power battery interchangeability wing removal Carefully selected die machine cut balsa plywood spruce parts supplied Also included complete hardware package plus detailed complete full-size rolled plans photo illustrated instruction manual 015 basic kit #ub 01SF basic kit plus 075 Hyperthrust II motor fused switch harness arc suppressing capacitors propeller adaptor 1 spinner Sonic-Tronics 8/4 folding prop #DS 01 5G basic kit plus 075 Hyperthrust II motor fused switch harness arc suppressing capacitors geared reduced drive propeller adaptor 1 spinner Windsor 12/8 folding propeller RC SoaringlBlakeslee oils Low Speed data disk andon 360K IBM format disk version Continued page 87Sailplane Design Performance Analysis34 David Frasers development series Program also now available HerkIt contains airfoil data Number 10 will $16 USBoth data disk Sailplane designPrinceton tests well several way Soartech #8 still availableprogram developed late Davidpreentered aircraft parameter files $20 US So too previousFraser coauthor Airfoils Low Speedscomplete instruction manual accompanies issues Soartech Herk can provide data disk contains data fromthe program disk price $35 sheet detailing content prices youthe Princeton wind tunnel tests assembledUS Canada Write Soartech send SASE him Soartech Jouriwiinto ASCII text files 360K IBM formatJournal address given above * 1504 N Horseshoe Circle Virginia Beachdisks $12 US Canada VA 23451 plane design program also Bob Fiorenzej Hobby Center Inc UPS Ordara Shipped Daily Daaier Yaliow Aircraft Send $300 Yellow info Package viait showroom i35mn Dia wo d Full Line Hobby Accasso 420 west SR 434 winter Springs FL 32708 1407327-6353 ec fl/WrX6OO1 Learn fly planes private field Five 6 day course $350 Open year round Send SASE complete info Southwest RC Flying 2818 Carolina NE Albuquerque NM 87110505-832-6394 Premium Grade 3/4 oz 38W 10 yrd mm $175 yd Lower Prices 30 yds & up Other Weights Availabie 17 Andrews Drive Daieviiie AL 36322 2051598-2287400-1000 OST 90 Model Aviation R OC e4 4 ENGENCE Wingspan 785 Wing Area 635 sq Airfoil S 3021 IIvEY YSTEMS 4 oRPORATIoN 675 Tower Lane West Chester PA 1938u 215 430-8645 Fax 215 430-0186

RADIO CONTROL SOARING MORE ON THE FALCON 880/ SD7037 Ernie Barter head guy VMC Flight manufacturer Model 20 retriever sent letter photos new Falcon 880 February column talked about flying Mark Allens 880 SD7037 airfoil ship weighed 59 ounces flew great mentioned seemed little too light Since no provision adding ballast didnt try greater weights Naturally very interested hear comments Ernie Enjoyed article re Falcon 880/ SD7037 am just now getting used 880 59 ounces youre correct too light have 7037 airfoil pre-sheeted Elite Lite 59 ounces floats have ballasted 64 69 ounces both weights different airplane have testing think 64-ounce weight about right although no noticeable difference between 64 69 for-what-its-worth department built Falcon rudder stab servo tail Rudder spar/sub spar fin stiffeners taped place fin gets very rigid configuration required twoounce nose ballast cant imagine building sixth servo rudder linkage staying within 59 ounces Handling superb rudder thanks aileron differential Thermal turns just fine slow speed approach turns flaps/crow problem thanks sharing findings Ernie Ive seen Electrics elevator servo fin first time Ive heard done glider Electrics course have ample built-in nose weight motor servo tail plus far balancing concerned Ernie must have taken cue F3E Electrics because get along rudders too Gliders always need added nose weight usual procedure put heavy stuff battery servos far forward possible elevator servo fin directly coupled stab linkage slop should eliminated hand launchers coming Handlaunched RC gliders HLG relatively small part hobby theyre probably fastest growing segment Youll see quite few new HLG kits coming out year appeal obvious inexpensive quick put together can tossed around small fields lunch hour also teach lot about flying low-level lift Bud Black Soaring League North Texas sent rundown seventh annual Southwest HLG contest will held July 11 Buds description contest might just encourage other clubs give HLG events try increased interest Class sailplanes San Antonio Austin Houston Tulsa should able exceed goal 30 contestants will fly 10minute Time Slot using hand launch optional Zip Start Also nine-minute AddEm-Up using 1A-inch rubber Dynaflite Up Starts four-minute max per flight developed Zip Start 10 feet 1R-inch rubber 20 feet 20-pound monofilament three pounds pull give weak arm no captive gorillas fighting chance against pilots strong arms doesnt get high launch gorilla does up odds bit Dynaflite rubber seems work better tubing weve tried think weve tried info Southwest HLG contest call Henry Bostick 214 279-8337 like SLNTs Zip Start idea arm too old weak get half height younger guys artificial assistance welcome course problem Zip Start spiked ground youre stuck launch location normal scene HLG contest pilots running over field attempting throw gliders lift marked other gliders low altitudes dealing thermals tend small trick launch directly brings up question Would legal have ones helper hold rubber end Zip Start pilot helper could trot over toward gaggle use Zip Start shoot right lift talking about three pounds pull holding rubber would no problem helper Heres another idea Someone should build RC version famous Jim Walker American Junior Interceptor benefit younger readers dont know about Jim Walker ingenious inventions Interceptor little all-balsa glider has wings fold back alongside fuselage much like WW II Grumman carrier planes eg Wildcat Hellcat Avenger shot air little catapultjust hefty rubber band 82 Model Aviation Blacks group photo contestants 1992 Southwest Hand Launch contest 93 event will July 30 pilots expected compete Tail end Ernie Barters Falcon 880 Elevator servo mounted bottom fin fin post taped place allow access New JR Charge Switch incorporates receptacle charge plug ni unarge wiicn mounted authors Saturn 29T currently under construction Interested Soaring Electric Flight Great So Are Northeast Sailplane Products carry comprehensive line silent flight prod ucts industry sell R/C Sail planes Electrics related accessories reference features hundreds products doz ens informative articles technical infor mation great sport RIO silent flight can meet needs abilities beginner expert dedicated pro viding personal customer service Check out NSP..youlI glad did Sailplane Products 1993 RC Soaring Electric Reference Northeast N N N N N Price S5 Northeast Sailplane Products16 Kirby Lane Wilton VT 05495 comprehensive reference Radio Control Soaring Electric Flight 802 658-9482 end short stick got Interceptor up about 30 feet top launch gliders speed dropped suffi ciently wings popped open small rubber band flew pretty well no-a iifoil glider Until couple years ago American Junior Aircraft Company Portland Oregon advertised A-J Interceptor Model Builder magazine price $695 RTF ready fly Ubuild kit $495 last bought 75 centsbut about 1946 JR Remote Control has new productsa new servo new airborne switchthat think will interest sailpianers new JR Switch terrific idea cord airborne pack plugs directly thus eliminating pigtail wire used regular switches wire always seems get lost under servo tray 057 x 13 x 076 inches Switch about twice size regular switches probably wont fit smaller gliders Retail list $1995 new JR servo No 3321 designed wing-mounted aileron flap operation high-quality servo coreless motor dual ball bearings Its dimensions 058 x 130 x 130 inches almost exactly same size Airtronics 141 3321 lighter thinner wing installations excellent choice JR 341 microservo 050 inches thick has superstrong nylon gears JR 3321 lists $8995 comes mounting lugs horizontal vertical mounting Whats unique about horizontal mounts molded center case intelligent innovation because allows use servo either left right wing Id better explain Standard procedure mount servos wings output shafts pointing toward wing tips first servo US market designed specifically wing mounting Airtronics 141 has horizontal mounting lugs both top bottom case normal installation need cut lugs off side other plus vertical lugs So wind up left- righthanded servos too big deal except means carrying twice spare wing servos field box Another excellent feature 3321 completely new extra-strong plastic gear train near-zero backlashand claimed zero deadband JR calls gear system Mega-Mesh Output gears have nearly double surface area similar size servos 3321 has good torque 598 ounce-inches moderate speed sound good too Understanding JR Servos new 28page booklet lists complete specs JR servos gives detailed descriptions Its available free Horizon Hobby Distributors write 4105 Fieldstone Rd Champaign IL 61821 call 217 355-0022 booklet says JR engineers took objective having virtually nonstrippable gear train system strong will probably pull servo its mounting block before losing gear Tips Tips July 1992 column reprinted piece Eastern Soaring Leagues newsletter ESL News edited Mike Lachowski piece called Tips Tips contained short explanation Michael Selig response question Mike put him about ailerons tipped-up wing tips Californian Blame Beron-Rawdon saw sent letter pointing out explanation incomplete sent Blames letter Michael asking comments Michael responded yes original ESL News piece addressed initial part turn steady-state thermal circling conditions think youll find aerodynamics theory interesting Im going reprint original piece Mike Lachowski plus follow-up letters Blame Michael Tips Tips Michael Selig have exchanged some notes observations aileron tip configurations various designs observation tip aileron placement Two-Meter June1993 83 Welcome world NSP first open unique reference will awe number quality products have Also ordering us easy fun because help step way order reference mail $700 $5 plus $2 s&h NSF Well ship reference via express mail arent completely satisfied simply send back prompt courteous refund Northeast Sailplane Products 16 Kirby Lane Williston Vermont 05495 ships Number two ships wing aile rons few inches tip bent tips upward Handling greatly improved Michael Seligs explanation follows Thanks note observation tip stall characteristics relation ailerons Mark Allen has found out same thing Maybe can explain Consider right turn Right aileron goes up left down low-speed wing right wing right turn sees downwash tiplet aileron will delay tip stall right wing extend ailerons way tip wont have favorable effect Right urn Iue upwah rnMdrnflSl NspeedUplot W-SPdP Left WingRight Wing Blame Beron-Rawdons letter read interest lead item column July MA seems something has lost translation Michael Selig Mike Lachowski description effect ailerons lift distribution Ci coefficient liftBB distribution wing tip area makes sense basic assumption direction aileron deflection mistaken example shown plane right thermal circle opposed right roll maneuver both wings going same speed As pointed out right wing going slowly since inside circle covering less distance per circle plane steady-state bank rolling means net roll moment due wings must zerothe left wing balances right wing Since right wing flying slowly left must pulling higher lift coefficient left wing Since aileron ships have very little dihedral way achieve greater lift coefficient droop inboard aileron andlor reflex outboard aileron exactly opposite what described article figure Moving end aileron inboard few inches still may help tip stall problem however Drooping aileron increases local effective angle attack local camber Leaving tip area unchanged effectively gives washout inboard tip reducing local lift coefficient tendency stall sharp discontinuity lift distribution end aileron however flow tends out decreasing lift near end aileron increasing lift just outboard aileron net effect still washout though purpose value bending tip panel aileron up fairly extreme dihedral angle very unclear may desirable increase overall dihedral plane increase spiral sta bility would efficient bending much wing up much less Furthermore bending just small tip area up lot likely cause tip stalls tip has lot dihedral its angle attack will strongly affected yaw angle aircraft tends yaw outboard circling vertical stabilizer lines up local curved flow outboard yaw increases angle attack tip panel increasing chance tip stall really wanted inhibit tip stall would leave tip dihedral zero perhaps bend down bit outboard yaw reduced angle attack subject cutting back aileron tip location should pointed out will reduce roll rate plain tip areas will damp roll motion regardless aileron deflection achieve equivalent roll rate remaining aileron throw will have increased inboard edge aileron extended inboard reducing potential flap area may easier envision effect aileron arrangement drawing analogy dihedral arrangement dihedral angle scheme rudder-elevator airplanes analogous chord location ailerons aileron ship instance standard outboard ailerons equivalent three-panel polyhedral wing flat center section Full-span ailerons equivalent V-dihedral ailerons cut back tip equivalent bending last few inches tip panels flat Model Aviation articles dihedral August November 1988 spiral stability September October 1990 address number points greater detail Michael Seligs letter Yes something lost translation tiplet reduces tip stall tendency placement aileron Aside Blame makes good point drawing shows right turn inboard aileron right wing aileron goes up initiate turn situation applies turn initiated period time inboard aileron produces favorable downwash alleviates tendency tip stall argument however does hold once glider steady-state circling flight situation becomes necessary hold opposite aileron prevent over-bank tendency right rudder maintain coordinated flight explanation having ailerons stop short tips best tip stall prevention steady-state turn glider circling flight inboard wing ie wing inside circle must produce higher lift coefficient outboard wing 84 Model Aviation products take maintenance building new heights Custom Cradles Feature Custom molded gray tubing--no ugiy fittings Special neoprene loam--impervious fuel oil Lo Boy Standard Large X-Large Tall Boy Standard Large X-Large N NEW Legz od 0 box s de NEW Radio Rack use folded position Call today order 1 -800-CRADLE-O 272-3530 Folds easy storage Custom design built last Ready use--no building Easily adjusted La Boy Custom Cradles Lo Boy Standard--i 0 tail 22 long 3 5 wide fuselage- 90 Lo Boy Large--i 4 tall 26 long 5to 8 wide fuselage -$2590 Lo Boy X-Large--1 6 tall 28 long 8 12 wide fuselage 2890 Tall Boy Custom Cradles Tall Boy Standard--32 tall 22 long 3to 5 wide fuselage 490 Tail Boy Large-28 tall 26 long 5to8 wide fuselage $3690 Tall Boy X-Large--26 tall 28 long 8 12 wide fuselage-----$3890 AccessorIes Legz--1 8 tall 18 wide hardware included fits boxes----$2990 Radio Rack--it folds compact protects radio home field 0 prIces Include shIppIng handlIng Send check money order today shIp UPS daIly o9Ws aatm zodaes 3177 East Fail Lowell Road SI Tucson Miona 85716 explained Blames letter glider made stall inboard wing will stall first since must operate higher lift coefficient Specifically stall will first take place over inboard aileron since doing work generate lift aileron extended tip tip stall will occur aileron stalls stalled portion wing moved toward fuselage stall no longer characterized tip stall can achieved moving ailerons toward fuselage since again part wing stalls first Thanks guys Im sure everyone now has better understanding design glider wings Just pass along some personal news Michael reports now married assistant professor aeronautical astronautical engineering University Illinois Champaign received under graduate degree U says Its nice back especially professor Ive heard Michael doing some design consulting work couple new gliders tremendous resource its exciting know continuing work model glider field Old-time sailplaners will remember Blame Beron-Rawdon designer Mirage 112-inch-span glider mid 1970s crewed Paul MacCreadys Gossamer Albatross senior member AeroVironment design team Solar Challenger Team Manager 1985 US F3B Team Blame now configuration designer McDonnell Douglas Long Beach Cal ifornia doesnt compete much days placed respectable 16th Visalia last October Aspiring sailplane designers wanting learn about dihedral spiral stability would well look up s series articles Model Aviation August through November 1988 September October 1990 respectively highly recommended Since aerodynamics kick thought would good spot print another interesting note Michael Selig Last year short article written Fritz Bien Connecticut made circuit club newsletters Fritz codesigner Dwight Holley 1981 F3B World Champions Gobbler last allwood glider win World Championship Anyway Fritzs point currently popular 5D7037 airfoil showed much lower drag older S3021 100000 Reynolds number Princeton tests reported Soartech #8 similarly shaped Fritz says Both airfoils fall right top other within single swipe sanding block dont know build accurately separate character istics two airfoils used airplane flapperonswhich never neutral position anyway Besides difference trailing edge two airfoils would 0008 less deviation airfoil Harley Michaelis made 5D7037 section wait Thats airfoil Harley made right approach having great drag polar lOOK Re range main difference between Michaelis airfoil S3021 5D7037 entry angle front top surface shallower 0030 inches out 12-inch chord would require lot sanding to average tA6inch sheeting other hand usual sag between ribs should produce excellent effect socalled super-airfoil moral story use actual 5D7037 PT airfoil original 5D7037 want duplicate wind tunnel tests duplicate airfoils vastly superior ones using fly wind tunnel field asked Michael Selig about Fritzs conclusions said think main content piece Fritz Bien finds difficult cosporison Michaehsu 5D7037 S3021 comparison Michoeliss 5D7037 5D7037 less trailing edge thickness of wings As happened Harley Michaelis well-known sailplane designer competitor Walla Walla Washington built 5D7037 wind tunnel wing model used Princeton Selig-Donovan-Fraser tests Fritz continues Using late David Frasers notation mean deviation between believe slight variations airfoil shape can lead significant changes performance may hard believe true reasons find airfoil design problem intriguing would agree Fritz wishes obtain performance shown Soartech #8 Continued page 57 June 1993 85 Legz Tail Boy have everything Call free brochure Dealer Inquires welcome UU-NO MORE WORRY ABOUT CRITICAL RADIO PLUGS BECOMING DISCONNECTED WHEN YOU USE THIS NEW WELL DESIGNED SAFETY ITEM PI Safety Ass U PROVIDES POSITIVE SECURELY LOCKED CONNECTION SNAP ACTION PROVIDES FOR OUICK AND EASY INSTALLATION AND REMOVAL OF THE SAFETY CLIP WHEN YOU UNPLUG THE CLIP CAN BE INSTALLED ON THE LARGER PORTION OF THE PLUG FOR SAFEKEEPING FOR USE ON PLANES HELICOPTERS CARS AND BOATS CONSTRUCTED OF NYLON FOR LIFETIME USE THREE SAFETY CLIPS SUPPLIED PER PACKAGE FOR USE ON BATTERY PACK AND AILERON PLUGS OR OTHER EXTENSIONS PACKAGE PRICE 9 SEE YOUR LOCAL HOBBY DEALER SAFETY CLIPS AVAILABLE FOR THE FOLLOWING PLUGS Airtronics Aristocraft 5 Slim Cirrus C Cox Futaba J Hitec JR Kyosho BUY PACK TO GUARD AGAINST IMPACT Parsons Pmducts PO Box 82038 Baton Rouge LA 70884-2038 Gee Bees turn Ofl write Henry Haffke RR #1 Box 22 Londonderry VT 05148 documentation information out just have tap right source giant will scale perfection Ive included photograph Ron Weisss latest Giant Scale gem Its 1/3-scale Fokker DVIII Hying Razor wingspan nine feet three inches 1650 square-inch area fuselage 74 inches long model weighs 30 pounds Kioritz 24cubic-inch engine powers Ron searched long hard authentic set threeviews Fokker found World War Aeroplanes Heinz J Nowarra s efforts Harleyford Publications model pictured has flying since 1985 Ron reports closely duplicates originals flight characteristics bird bit antsy landings like other models WW aircraft handles like big Cub air anyone interested duplicating big DVIII Ron offers drawings Contact Ron Weiss 20 Linda P1 Huntington NY 11743and include large SASE Ron also offers definitive 1A-scale plans set 1930 Fleet 2 biplane Ive seen Fleet drawings theyre superb columnists get gray hair addition fine letters receive readers get manner news releases manufacturers model-related products latter 99% great value keeping informed whats available make modelers life easier remaining percent obtuse confuse heck out rational person Got latter about week ago What amounted instruction sheet rather complex device Although named device indicated its price just functioned almost complete mystery news release soon found home proverbial File 13 circular oneand noted several new gray tendrils temples Make em big fly em big Back next month oaringlBlakeslee Continued page 85 actual test model coordinates PT designation should used will add probably necessary average error greater 0004 inches Reference effect made page 52 90 Soartech #8 food thought what would-be competitors constantly searching latest hot airfoil now told probably cant build wing performs book says Some builders may find no-suchthing-as-perfect concept depressing submit however can actually add fun building flying comparing model sailplanes shops carefully cut ribs make templates cut foam cores bag fiberglass obechi skins sand out imperfections thinking little change here.a tweak there.this glider could turn out being demon supership live hopes hitting jackpot Soartech #9 available Soartech #8 Airfoils Low Speeds popular has delayed publication next number Number 9 now available $8 postage paid US Included #9 following papers Use Wind Tunnel Data Design RC Contest Model Sailplanes Martin Simons Static Longitudinal Stability CROCCO Method Ferdi Gale Fear Flying Wing Noel Falconer Wing Load Computation Max Chernoff What Can Learned Paper Airplanes Hewitt Phillips Built-In Sheeting Dennis Oglesby Publisher Herk Stokely says has enough material hand put out Soartech #10 fairly soon will 200 pages long will feature photo essay Martin Bamert covering aspects creation completely composite model Continued page 90 BPLGAIN ION IDOL ing Control can nightmare 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 modeling radio repair So avoid inflated repair Costs undue service time Radio South fast economical in-house radio service can depend Radio South customer satisfaction isnt just motto Its way life Let us put back control D Fuataba KRAFT CN jAIRThMICS 5524 N Palafox Pensacola FL 32503 repair information 904 434-0909 1-800-962-7802 Toll Free Order Line Orders Only Please) June 1993 87 New Kits 1993 Viper sleek new design outstanding maneuverability stability track like arrow Viper 40 plus size engines motors emphasis proper construction minimize flying weight optimize performance design utilizes fully symmetrical tapered airfoil has ample room retracts fuselage can easily hold power batteries required electric flight desired VIPER Wingspan 60 Wing Area 620 sq Airfoil symmetrical #DS 016 basic kit kit features formed landing gear complete hardware package canopy selected die machine cut balsa plywood spruce hardwood parts Also included complete fulisize rolled plans photo illustrated instruction manual new high performance sailplane designed electric powered flight new two meter span Vengence can launch speck size less minute 075 Hyperthrust II motor seven cells kit has designed rudder elevator motor operation utilizes fuselage designed large enough accommodate 12 cell 1200 mAh larger packs including taller cell batteries design also includes hatch bottom facilitate power battery interchangeability wing removal Carefully selected die machine cut balsa plywood spruce parts supplied Also included complete hardware package plus detailed complete full-size rolled plans photo illustrated instruction manual 015 basic kit #ub 01SF basic kit plus 075 Hyperthrust II motor fused switch harness arc suppressing capacitors propeller adaptor 1 spinner Sonic-Tronics 8/4 folding prop #DS 01 5G basic kit plus 075 Hyperthrust II motor fused switch harness arc suppressing capacitors geared reduced drive propeller adaptor 1 spinner Windsor 12/8 folding propeller RC SoaringlBlakeslee oils Low Speed data disk andon 360K IBM format disk version Continued page 87Sailplane Design Performance Analysis34 David Frasers development series Program also now available HerkIt contains airfoil data Number 10 will $16 USBoth data disk Sailplane designPrinceton tests well several way Soartech #8 still availableprogram developed late Davidpreentered aircraft parameter files $20 US So too previousFraser coauthor Airfoils Low Speedscomplete instruction manual accompanies issues Soartech Herk can provide data disk contains data fromthe program disk price $35 sheet detailing content prices youthe Princeton wind tunnel tests assembledUS Canada Write Soartech send SASE him Soartech Jouriwiinto ASCII text files 360K IBM formatJournal address given above * 1504 N Horseshoe Circle Virginia Beachdisks $12 US Canada VA 23451 plane design program also Bob Fiorenzej Hobby Center Inc UPS Ordara Shipped Daily Daaier Yaliow Aircraft Send $300 Yellow info Package viait showroom i35mn Dia wo d Full Line Hobby Accasso 420 west SR 434 winter Springs FL 32708 1407327-6353 ec fl/WrX6OO1 Learn fly planes private field Five 6 day course $350 Open year round Send SASE complete info Southwest RC Flying 2818 Carolina NE Albuquerque NM 87110505-832-6394 Premium Grade 3/4 oz 38W 10 yrd mm $175 yd Lower Prices 30 yds & up Other Weights Availabie 17 Andrews Drive Daieviiie AL 36322 2051598-2287400-1000 OST 90 Model Aviation R OC e4 4 ENGENCE Wingspan 785 Wing Area 635 sq Airfoil S 3021 IIvEY YSTEMS 4 oRPORATIoN 675 Tower Lane West Chester PA 1938u 215 430-8645 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