Radio Control Sport Aerobatics Ron Van Putte JUNES column contained suggestion softening Part Dave Brown epoxy putting top off container microwave oven 20 30 seconds editor inserted comment example showing Id fortunate get away doing because some people severely allergic heated epoxy Actually dont think fortunate Fortu nate lucky bet something against 1000-to-one odds win Since very few people allergic person cited example Id say person whos allergic unfortunate Unfortunate odds 1000-to-one favor lose Because Im flight test business continually deal safety engineers must decide whether testing want safe must weigh odds failure occurring versus implications failure difficult job because dealing mens lives millions dollars worth equipment Never theless am often given go-ahead test though single failure could cause loss alrcraft life pilot because probability failure infinitesimal Similarly must weigh odds considering doing lot different things volved RC didnt particular thing because remote possibility failure causing catastrophic problem wed never show up flying fieldmuch less attempt fly RC airplanes Consequently will continue soften Brown Part epoxy microwave oven because have determined am allergic its fumes Prudent modelers also determine aller gic heated epoxy can too Before climb off soapbox let make final brief comment AMA Commentary printed June 1987 column WEIGHT FiGURE 1 x Ron talks about mythical pendulum effect lateral stability month simplest case forces acting model bankbut turning agree use color-coded frequency channel-number tags would confuse users Channel 42 YEL/RED Channel 24 RED YEL believe situation would conservative Namely both modelers would check before flying editorial staff magazine comfortable idea lending en couragement practice heating epoxy microwave oven IfRon Van Putte wants thats business feel others should avoid practice still too unknowns about situation example Ron said modeler suffered severe reaction microwaved epoxyin example cited John Preston suffering severe allergic reaction Thats what modelers doctor said physi cian inferred reaction toxic mes Safety Comes First columnist John Preston now looking subject heating epoxies microwave oven will have hoped definitive report subject near future meantime based considerations ofpossible unexpected release toxic fumes initiation severe allergic reaction discourage practice heating epoxy microwave oven RMcM years weve heard columnists some fellow fliers say reason high-wing air planes stable laterally lowwing counterparts because pendulum effect last time read something inside snapped Im forced comment pendulum effect another convenient explanations used account UFTL UFTR FIGURE 2 Heres same condition plane dihedral Note lift vectors still perpendicular wing observed phenomenon has no basis fact Having written above Im aware will wounded cry proponents may get letters same volume people side other downwind turn argument Nevertheless theres simple way resolve itand look forces moments acting highwing model decide what really happens Figure 1 shows high-wing airplane unaccelerated bank alrplane placed attitude resulting forces moments will cause accelerate linearly angularly airplane Ive drawn has no dihedral wing makes easier make point doesnt affect results lift force shown acting perpendicular wing would still perpendicular wing dihedral shown Figure 2 sum up effect lift weight X Y directions Figure 1 have Sum X forces Weight times Sine Bank Angie Sum Y forces Lift L plus Lift R minus Weight times Cosine Bank Angle First lets take look Y equation forces add up zero no tendency accelerate direction Y axis sum Lift forces greater Y component Weight airplane will accelerate direction start turn right course thats add Up elevator bankit creates turn Now lets look X equation Unless bank angle zero theres no way sum forces can zero Consequently airplane will tend accelerate direction low Don Lowe redesigned nose Phoenix 91 fairing spinner smoothly making dramatic change planes appearance right Don getting picture Sam Leonards plane Flying Lowe column ACM magazine 48 Model Aviation wing will develop sideslip Full-scale wind-tunnel tests have demonstrated highwing airplane sideslip usually develops restoring moment high-mounted wing creates dihedral effect tends return airplane level flight Conversely low-mounted wing usually develops anhedral effect reverse dihedral tends increase bank angle reason high-wing airplanes require much dihedral low-wing airplanes what about pendulum effect Pro ponents say effect weight airplane causes right itselfjust pendulum tends hang vertical order happen moment must developed about centerof-mass airplane tends right moment contribution lift right wing equal opposite lift left wing weight causes no moment about center-of-mass airplane Consequently no restoring moment generated right airplane Saying high-wing airplane exhibits roll stability due pendulum effect incorrect explanation observed phenome non Give credit sideslip high-wing dihedral effect As long Im taking sides several issues let straddle two sides fence question What makes best trainer RC airplane Like questions has no simple answer However propo nents can covered two blankets claim slow two three channel very stable low-powered airplane way go other side says airplane should faster have three four channels stable moderately powered first category Glider-type airplanes rudder elevator control perhaps throt tle control too 049 10 cu engines power second category high-wing airplanes rudder elevator perhaps aileron throttle control 25 40 cu engine power Experts training say best way learn something like flying RC airplane pack much training poible excessive stress fatigue successful ses sions close together feasible will note several qualifiers statement Key training success having airplane fly people means keeping airplane piece Beginners hard airplanes keeping piece depends type airplane qualityand availabil ity instruction learning ability student degree control instructor has luck Working backward Luck tough control Nasty gusts wind components fail radios cant prevented However amount control instructor has can managed best things RC manu facturing community came up has unfortunately largely discarded buddy box feature Instructors can save lot airplanes being able take control students airplane instantly fumbling shared transmitter buddy-box should used whenever possible/available Lets face students created equal Ive students solo weekend Ive some never will learn fly Most students learn enough solo six eight sessions spread over three- four-week period have decent instructor Continued page 150 PRECISION Hawker Hurricane MI lic $14950 Wing Span 62 inch Weight 61/2 8/2 lbs depends flaps retracts Full Scale Detail includes 5 view flaps retracts setup Engine 65-90 FS 60 TS Fiberglass cowl Aero-Pacer $8900 Sport-Trainer Wing Span 641/2 inch Weight 5-7 Ibs Wing load 19-25 oz Engine 45-65 ES 2945 TS Easily converted tail dragger flaps Video construction tape available BabyPacer $5950 Versatile small size Wing Span 50 inch Weight 25-35 Ibs Wing load 19-25 oz Engine 15-40 ES 19-25 TS ELECTRIC HANDCUT SELECTED BALSA AND HARDWOOD PARTS WITH MADE IN USA QUALITV DH6O Gipsy Moth $10900 Wing Span 541/4 inch Weight 5-6 Lb Wing Load 15 oz Engine 45-65 ES 35-50 TS Flybaby 2 1 Combo Flybaby $7950 Bipe $9500 Combo $11000 Wing Span 56 44 inches Weight 4-5 Ibs Wing Load 22 14 Engine 30-45 ES 25-40 TS AT FIELD CONVERSION 10 MIN l ODROME MODELS LTD OEL5LTD/ L il"2623 S MILLER RD SAGINAW MI 48603 517 781-3000 Limited SupplyTuned Pipe Header 40-45 Size Fits OS 40-45 FSR K&B 40 HP 40 HGK 40-45 Royal-Thunder 7ger-Magnum 40-45 8 Size Fits 05 25-28 FSR K&B Sportster 20 sold stores INCL UDES Tuned Pipe Silencer Header Silicone joint tube Moun tin strop screws pressure top ond am ing wire Please Add $200 P511 per order CA residents odd sales tax RJL Industries 1831 Business Center Dr Duarte CA 91010 818 359-0016 August 198749 VISA Mastercard COD money order Add $550 Post Handling Mich residents add 4% Video Catalog $1000 Beta VHS $5 rebate order Cowls either ABS Fiberglass Plan Packs Available LOG$750 AL 1000s choose Solar rubber powered gliders copters scale lasercut diecut youcut rockets origami some wing span 6 feet ALL MADE OUt OF PAPER Limited number printed 18188423455PAPER AIRPLANES INTERNATIONAL1213822-9185 1521 Morningside Drive Burbank California91506USA Dodgson has new construction videotapes ready shipment Bobs Tape No came out last winter showed beautiful flying shots four planes produces design philos ophy New tape No 2 shows Dave Banks wing construction sequences runs two hours Tape No 3 shows fuselage construction linkage layouts 90 minutes havent seen new tapes Id imagine would invaluable anyone buildingor thinking buildingone Bobs kits refundable deposit $15 $30 $40 depending whether order two three tapes time Shipping handling $10 $15 $20 making total $25 $45 $60 Other news Bob extra $45 will partially pre-build fuselage new Windsong Camano Pixie Formers bulk heads elevator bearings nose wing saddle plywood decking installed rein forced called plans work done jig fuselage locked perfect alignment Bob also says business going great add help get backlog down manageable level Bobs address 21230 Damson Road Bothell WA 98021 phone number 206 776-8067 Valley Forges Fifth Annual Sailplane Contest will held August 15-16 site Valley Forge Signal Seekers flying field near King Prussia PA Sportsman Expert Junior will flown both class D class B both days Hand-Launch class event will flown both days Sport Scale Sunday biggest contests East hear its well-run lot fun CD will Fran Olix also Soaring CD Ehe Nats year info write Fran 764 Alexander Drive Hatfield PA 19440 phone 215 341-6713 day time 361-9516 evenings end column month Id like share contents note sent Mrs Mary Holley addressed Sailplaners expressed sympathy Dwights passing last December Model Soaring large part Dwights life know acknowledgement accomplishments type Champion would mean great deal himas does Bryon Blakeslee 3134 Winnebago Dr Sedalia CO 80135 Please enclose SASE responses SEND SASE FOR LITERATURE SHEETS Its also true instructors created equal Some people can fly own airplanes just fine cant teach others really good instructor can dramatically shorten training time student Now get tough onethe trainer airplane As mentioned earlier key learn ing fly RC keeping airplane piece good student has good instructor buddy-box needs entirely different airplane poor student no instructor powered Glider good choice trainer airplane students slow learners have poor/no instructors and/or no buddy-box type airplane inherently stable can often fly itself out trouble much easier fly land because moves relatively slowly novice pilot has better chance keep up aircrafts motion permits student time evaluate orientation airplane figure out what wing loading usually fairly low often allows survive crashes good shape wouldnt everyone want learn fly using powered Glider Well depending abilities novice pilot instructor availability buddy-box some students will learn lot faster others Pilots seldom use powered Glider type trainer-airplane much radio check airplane after learn fly So move advanced trainer much like airplane other proponents would have recommended start out means investment money long run its wasted pilot can learn fly quickly Having said Id straddle both sides issue must add beginner can decide airplane best satisfies training situation hes found himself Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Electrics/Kopski Continued page 51 Part No 4032 priced $6 Cell size just mentioned above since readers experience some confusion difficulty dimension thought Id offer some additional information Before con tinuing may want reference April 87 MA column same subject 36 Cell size generally expressed either ampere-hours milliampere-hours expressions simply refer amount charge cell capable accepting delivering ie big tank electrically As example popular 12 Ah ampere hour cell can expected deliver about 12 amps hour 012 amps 10 hours such total current-time product So sixminute ho-hour motor run flight average motor current would have 12 amperes completely drain cell assuming started fully charged pack because 12 amps x Yo hour mpere-hours course cell capacity can also expressed minutes Thus same 1 2-Ah cellor pack can said have 72 ampere-minute capacity since 60 minutes hour 12 x 60 ust portion size description identifies time-factor can expressed way also can part describes electric current Thus 1 2-Ah example can also described having 1200 milliampere-hour capacity since 1000 milliamperes ampere Miii means 4ooosee July 1985 issue MA Combining above could call example 72000 milliampere-minute cell pack Well little cumbersome routinely used expression However does serve additional illustration idea cell size Great say what use Well lets say wanted fast-charge rather small motor pack Free Flight Electric Lets say using 250-mAh cells wanted charge 15 minutesthe longest period can set time-switch charger question comes up much charge current should used Remember doesnt matter cells areonly cells pack must same size obviously way look question approach realize 250 mAh one-quarter ampere-hour since 250/1000 could charge 1/4 ampere 250 milliamps hourbut thats four individual turns 15-minute hour charger-timer knob Since really want job just timer-knob turn charging has done four times faster Clearly example would charge 4 x 250 mulliamps 4 x amp amp 15 minutes Again 1 amp x 15 minutes p x ere-hour 250/1000 ampere-hour milliampere hours about something uneven Continued page 152 150 Model Aviation r3/4 SCALE CLASSICSHigh Performance Rubber Powered $1795 / KORDA 33___________ DEALER AND DISTRI BUTOR_________ INOUIRES INVITED PLUS 8 MORE RUBBER POWERED MODELS KIT INCLUDES FOLDING PROP MATERIALS SELECT WOODS FULL SIZE PLAN CLOUD 33 R/NmocielsPouox 5059ALAMOGORDO NM 88311 CLODHOPPER RC Aerobatics/Van Putte Continued page 49 responding advertIsers mention read about ModelAviation
Edition: Model Aviation - 1987/08
Page Numbers: 48, 49, 150
Radio Control Sport Aerobatics Ron Van Putte JUNES column contained suggestion softening Part Dave Brown epoxy putting top off container microwave oven 20 30 seconds editor inserted comment example showing Id fortunate get away doing because some people severely allergic heated epoxy Actually dont think fortunate Fortu nate lucky bet something against 1000-to-one odds win Since very few people allergic person cited example Id say person whos allergic unfortunate Unfortunate odds 1000-to-one favor lose Because Im flight test business continually deal safety engineers must decide whether testing want safe must weigh odds failure occurring versus implications failure difficult job because dealing mens lives millions dollars worth equipment Never theless am often given go-ahead test though single failure could cause loss alrcraft life pilot because probability failure infinitesimal Similarly must weigh odds considering doing lot different things volved RC didnt particular thing because remote possibility failure causing catastrophic problem wed never show up flying fieldmuch less attempt fly RC airplanes Consequently will continue soften Brown Part epoxy microwave oven because have determined am allergic its fumes Prudent modelers also determine aller gic heated epoxy can too Before climb off soapbox let make final brief comment AMA Commentary printed June 1987 column WEIGHT FiGURE 1 x Ron talks about mythical pendulum effect lateral stability month simplest case forces acting model bankbut turning agree use color-coded frequency channel-number tags would confuse users Channel 42 YEL/RED Channel 24 RED YEL believe situation would conservative Namely both modelers would check before flying editorial staff magazine comfortable idea lending en couragement practice heating epoxy microwave oven IfRon Van Putte wants thats business feel others should avoid practice still too unknowns about situation example Ron said modeler suffered severe reaction microwaved epoxyin example cited John Preston suffering severe allergic reaction Thats what modelers doctor said physi cian inferred reaction toxic mes Safety Comes First columnist John Preston now looking subject heating epoxies microwave oven will have hoped definitive report subject near future meantime based considerations ofpossible unexpected release toxic fumes initiation severe allergic reaction discourage practice heating epoxy microwave oven RMcM years weve heard columnists some fellow fliers say reason high-wing air planes stable laterally lowwing counterparts because pendulum effect last time read something inside snapped Im forced comment pendulum effect another convenient explanations used account UFTL UFTR FIGURE 2 Heres same condition plane dihedral Note lift vectors still perpendicular wing observed phenomenon has no basis fact Having written above Im aware will wounded cry proponents may get letters same volume people side other downwind turn argument Nevertheless theres simple way resolve itand look forces moments acting highwing model decide what really happens Figure 1 shows high-wing airplane unaccelerated bank alrplane placed attitude resulting forces moments will cause accelerate linearly angularly airplane Ive drawn has no dihedral wing makes easier make point doesnt affect results lift force shown acting perpendicular wing would still perpendicular wing dihedral shown Figure 2 sum up effect lift weight X Y directions Figure 1 have Sum X forces Weight times Sine Bank Angie Sum Y forces Lift L plus Lift R minus Weight times Cosine Bank Angle First lets take look Y equation forces add up zero no tendency accelerate direction Y axis sum Lift forces greater Y component Weight airplane will accelerate direction start turn right course thats add Up elevator bankit creates turn Now lets look X equation Unless bank angle zero theres no way sum forces can zero Consequently airplane will tend accelerate direction low Don Lowe redesigned nose Phoenix 91 fairing spinner smoothly making dramatic change planes appearance right Don getting picture Sam Leonards plane Flying Lowe column ACM magazine 48 Model Aviation wing will develop sideslip Full-scale wind-tunnel tests have demonstrated highwing airplane sideslip usually develops restoring moment high-mounted wing creates dihedral effect tends return airplane level flight Conversely low-mounted wing usually develops anhedral effect reverse dihedral tends increase bank angle reason high-wing airplanes require much dihedral low-wing airplanes what about pendulum effect Pro ponents say effect weight airplane causes right itselfjust pendulum tends hang vertical order happen moment must developed about centerof-mass airplane tends right moment contribution lift right wing equal opposite lift left wing weight causes no moment about center-of-mass airplane Consequently no restoring moment generated right airplane Saying high-wing airplane exhibits roll stability due pendulum effect incorrect explanation observed phenome non Give credit sideslip high-wing dihedral effect As long Im taking sides several issues let straddle two sides fence question What makes best trainer RC airplane Like questions has no simple answer However propo nents can covered two blankets claim slow two three channel very stable low-powered airplane way go other side says airplane should faster have three four channels stable moderately powered first category Glider-type airplanes rudder elevator control perhaps throt tle control too 049 10 cu engines power second category high-wing airplanes rudder elevator perhaps aileron throttle control 25 40 cu engine power Experts training say best way learn something like flying RC airplane pack much training poible excessive stress fatigue successful ses sions close together feasible will note several qualifiers statement Key training success having airplane fly people means keeping airplane piece Beginners hard airplanes keeping piece depends type airplane qualityand availabil ity instruction learning ability student degree control instructor has luck Working backward Luck tough control Nasty gusts wind components fail radios cant prevented However amount control instructor has can managed best things RC manu facturing community came up has unfortunately largely discarded buddy box feature Instructors can save lot airplanes being able take control students airplane instantly fumbling shared transmitter buddy-box should used whenever possible/available Lets face students created equal Ive students solo weekend Ive some never will learn fly Most students learn enough solo six eight sessions spread over three- four-week period have decent instructor Continued page 150 PRECISION Hawker Hurricane MI lic $14950 Wing Span 62 inch Weight 61/2 8/2 lbs depends flaps retracts Full Scale Detail includes 5 view flaps retracts setup Engine 65-90 FS 60 TS Fiberglass cowl Aero-Pacer $8900 Sport-Trainer Wing Span 641/2 inch Weight 5-7 Ibs Wing load 19-25 oz Engine 45-65 ES 2945 TS Easily converted tail dragger flaps Video construction tape available BabyPacer $5950 Versatile small size Wing Span 50 inch Weight 25-35 Ibs Wing load 19-25 oz Engine 15-40 ES 19-25 TS ELECTRIC HANDCUT SELECTED BALSA AND HARDWOOD PARTS WITH MADE IN USA QUALITV DH6O Gipsy Moth $10900 Wing Span 541/4 inch Weight 5-6 Lb Wing Load 15 oz Engine 45-65 ES 35-50 TS Flybaby 2 1 Combo Flybaby $7950 Bipe $9500 Combo $11000 Wing Span 56 44 inches Weight 4-5 Ibs Wing Load 22 14 Engine 30-45 ES 25-40 TS AT FIELD CONVERSION 10 MIN l ODROME MODELS LTD OEL5LTD/ L il"2623 S MILLER RD SAGINAW MI 48603 517 781-3000 Limited SupplyTuned Pipe Header 40-45 Size Fits OS 40-45 FSR K&B 40 HP 40 HGK 40-45 Royal-Thunder 7ger-Magnum 40-45 8 Size Fits 05 25-28 FSR K&B Sportster 20 sold stores INCL UDES Tuned Pipe Silencer Header Silicone joint tube Moun tin strop screws pressure top ond am ing wire Please Add $200 P511 per order CA residents odd sales tax RJL Industries 1831 Business Center Dr Duarte CA 91010 818 359-0016 August 198749 VISA Mastercard COD money order Add $550 Post Handling Mich residents add 4% Video Catalog $1000 Beta VHS $5 rebate order Cowls either ABS Fiberglass Plan Packs Available LOG$750 AL 1000s choose Solar rubber powered gliders copters scale lasercut diecut youcut rockets origami some wing span 6 feet ALL MADE OUt OF PAPER Limited number printed 18188423455PAPER AIRPLANES INTERNATIONAL1213822-9185 1521 Morningside Drive Burbank California91506USA Dodgson has new construction videotapes ready shipment Bobs Tape No came out last winter showed beautiful flying shots four planes produces design philos ophy New tape No 2 shows Dave Banks wing construction sequences runs two hours Tape No 3 shows fuselage construction linkage layouts 90 minutes havent seen new tapes Id imagine would invaluable anyone buildingor thinking buildingone Bobs kits refundable deposit $15 $30 $40 depending whether order two three tapes time Shipping handling $10 $15 $20 making total $25 $45 $60 Other news Bob extra $45 will partially pre-build fuselage new Windsong Camano Pixie Formers bulk heads elevator bearings nose wing saddle plywood decking installed rein forced called plans work done jig fuselage locked perfect alignment Bob also says business going great add help get backlog down manageable level Bobs address 21230 Damson Road Bothell WA 98021 phone number 206 776-8067 Valley Forges Fifth Annual Sailplane Contest will held August 15-16 site Valley Forge Signal Seekers flying field near King Prussia PA Sportsman Expert Junior will flown both class D class B both days Hand-Launch class event will flown both days Sport Scale Sunday biggest contests East hear its well-run lot fun CD will Fran Olix also Soaring CD Ehe Nats year info write Fran 764 Alexander Drive Hatfield PA 19440 phone 215 341-6713 day time 361-9516 evenings end column month Id like share contents note sent Mrs Mary Holley addressed Sailplaners expressed sympathy Dwights passing last December Model Soaring large part Dwights life know acknowledgement accomplishments type Champion would mean great deal himas does Bryon Blakeslee 3134 Winnebago Dr Sedalia CO 80135 Please enclose SASE responses SEND SASE FOR LITERATURE SHEETS Its also true instructors created equal Some people can fly own airplanes just fine cant teach others really good instructor can dramatically shorten training time student Now get tough onethe trainer airplane As mentioned earlier key learn ing fly RC keeping airplane piece good student has good instructor buddy-box needs entirely different airplane poor student no instructor powered Glider good choice trainer airplane students slow learners have poor/no instructors and/or no buddy-box type airplane inherently stable can often fly itself out trouble much easier fly land because moves relatively slowly novice pilot has better chance keep up aircrafts motion permits student time evaluate orientation airplane figure out what wing loading usually fairly low often allows survive crashes good shape wouldnt everyone want learn fly using powered Glider Well depending abilities novice pilot instructor availability buddy-box some students will learn lot faster others Pilots seldom use powered Glider type trainer-airplane much radio check airplane after learn fly So move advanced trainer much like airplane other proponents would have recommended start out means investment money long run its wasted pilot can learn fly quickly Having said Id straddle both sides issue must add beginner can decide airplane best satisfies training situation hes found himself Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Electrics/Kopski Continued page 51 Part No 4032 priced $6 Cell size just mentioned above since readers experience some confusion difficulty dimension thought Id offer some additional information Before con tinuing may want reference April 87 MA column same subject 36 Cell size generally expressed either ampere-hours milliampere-hours expressions simply refer amount charge cell capable accepting delivering ie big tank electrically As example popular 12 Ah ampere hour cell can expected deliver about 12 amps hour 012 amps 10 hours such total current-time product So sixminute ho-hour motor run flight average motor current would have 12 amperes completely drain cell assuming started fully charged pack because 12 amps x Yo hour mpere-hours course cell capacity can also expressed minutes Thus same 1 2-Ah cellor pack can said have 72 ampere-minute capacity since 60 minutes hour 12 x 60 ust portion size description identifies time-factor can expressed way also can part describes electric current Thus 1 2-Ah example can also described having 1200 milliampere-hour capacity since 1000 milliamperes ampere Miii means 4ooosee July 1985 issue MA Combining above could call example 72000 milliampere-minute cell pack Well little cumbersome routinely used expression However does serve additional illustration idea cell size Great say what use Well lets say wanted fast-charge rather small motor pack Free Flight Electric Lets say using 250-mAh cells wanted charge 15 minutesthe longest period can set time-switch charger question comes up much charge current should used Remember doesnt matter cells areonly cells pack must same size obviously way look question approach realize 250 mAh one-quarter ampere-hour since 250/1000 could charge 1/4 ampere 250 milliamps hourbut thats four individual turns 15-minute hour charger-timer knob Since really want job just timer-knob turn charging has done four times faster Clearly example would charge 4 x 250 mulliamps 4 x amp amp 15 minutes Again 1 amp x 15 minutes p x ere-hour 250/1000 ampere-hour milliampere hours about something uneven Continued page 152 150 Model Aviation r3/4 SCALE CLASSICSHigh Performance Rubber Powered $1795 / KORDA 33___________ DEALER AND DISTRI BUTOR_________ INOUIRES INVITED PLUS 8 MORE RUBBER POWERED MODELS KIT INCLUDES FOLDING PROP MATERIALS SELECT WOODS FULL SIZE PLAN CLOUD 33 R/NmocielsPouox 5059ALAMOGORDO NM 88311 CLODHOPPER RC Aerobatics/Van Putte Continued page 49 responding advertIsers mention read about ModelAviation
Edition: Model Aviation - 1987/08
Page Numbers: 48, 49, 150
Radio Control Sport Aerobatics Ron Van Putte JUNES column contained suggestion softening Part Dave Brown epoxy putting top off container microwave oven 20 30 seconds editor inserted comment example showing Id fortunate get away doing because some people severely allergic heated epoxy Actually dont think fortunate Fortu nate lucky bet something against 1000-to-one odds win Since very few people allergic person cited example Id say person whos allergic unfortunate Unfortunate odds 1000-to-one favor lose Because Im flight test business continually deal safety engineers must decide whether testing want safe must weigh odds failure occurring versus implications failure difficult job because dealing mens lives millions dollars worth equipment Never theless am often given go-ahead test though single failure could cause loss alrcraft life pilot because probability failure infinitesimal Similarly must weigh odds considering doing lot different things volved RC didnt particular thing because remote possibility failure causing catastrophic problem wed never show up flying fieldmuch less attempt fly RC airplanes Consequently will continue soften Brown Part epoxy microwave oven because have determined am allergic its fumes Prudent modelers also determine aller gic heated epoxy can too Before climb off soapbox let make final brief comment AMA Commentary printed June 1987 column WEIGHT FiGURE 1 x Ron talks about mythical pendulum effect lateral stability month simplest case forces acting model bankbut turning agree use color-coded frequency channel-number tags would confuse users Channel 42 YEL/RED Channel 24 RED YEL believe situation would conservative Namely both modelers would check before flying editorial staff magazine comfortable idea lending en couragement practice heating epoxy microwave oven IfRon Van Putte wants thats business feel others should avoid practice still too unknowns about situation example Ron said modeler suffered severe reaction microwaved epoxyin example cited John Preston suffering severe allergic reaction Thats what modelers doctor said physi cian inferred reaction toxic mes Safety Comes First columnist John Preston now looking subject heating epoxies microwave oven will have hoped definitive report subject near future meantime based considerations ofpossible unexpected release toxic fumes initiation severe allergic reaction discourage practice heating epoxy microwave oven RMcM years weve heard columnists some fellow fliers say reason high-wing air planes stable laterally lowwing counterparts because pendulum effect last time read something inside snapped Im forced comment pendulum effect another convenient explanations used account UFTL UFTR FIGURE 2 Heres same condition plane dihedral Note lift vectors still perpendicular wing observed phenomenon has no basis fact Having written above Im aware will wounded cry proponents may get letters same volume people side other downwind turn argument Nevertheless theres simple way resolve itand look forces moments acting highwing model decide what really happens Figure 1 shows high-wing airplane unaccelerated bank alrplane placed attitude resulting forces moments will cause accelerate linearly angularly airplane Ive drawn has no dihedral wing makes easier make point doesnt affect results lift force shown acting perpendicular wing would still perpendicular wing dihedral shown Figure 2 sum up effect lift weight X Y directions Figure 1 have Sum X forces Weight times Sine Bank Angie Sum Y forces Lift L plus Lift R minus Weight times Cosine Bank Angle First lets take look Y equation forces add up zero no tendency accelerate direction Y axis sum Lift forces greater Y component Weight airplane will accelerate direction start turn right course thats add Up elevator bankit creates turn Now lets look X equation Unless bank angle zero theres no way sum forces can zero Consequently airplane will tend accelerate direction low Don Lowe redesigned nose Phoenix 91 fairing spinner smoothly making dramatic change planes appearance right Don getting picture Sam Leonards plane Flying Lowe column ACM magazine 48 Model Aviation wing will develop sideslip Full-scale wind-tunnel tests have demonstrated highwing airplane sideslip usually develops restoring moment high-mounted wing creates dihedral effect tends return airplane level flight Conversely low-mounted wing usually develops anhedral effect reverse dihedral tends increase bank angle reason high-wing airplanes require much dihedral low-wing airplanes what about pendulum effect Pro ponents say effect weight airplane causes right itselfjust pendulum tends hang vertical order happen moment must developed about centerof-mass airplane tends right moment contribution lift right wing equal opposite lift left wing weight causes no moment about center-of-mass airplane Consequently no restoring moment generated right airplane Saying high-wing airplane exhibits roll stability due pendulum effect incorrect explanation observed phenome non Give credit sideslip high-wing dihedral effect As long Im taking sides several issues let straddle two sides fence question What makes best trainer RC airplane Like questions has no simple answer However propo nents can covered two blankets claim slow two three channel very stable low-powered airplane way go other side says airplane should faster have three four channels stable moderately powered first category Glider-type airplanes rudder elevator control perhaps throt tle control too 049 10 cu engines power second category high-wing airplanes rudder elevator perhaps aileron throttle control 25 40 cu engine power Experts training say best way learn something like flying RC airplane pack much training poible excessive stress fatigue successful ses sions close together feasible will note several qualifiers statement Key training success having airplane fly people means keeping airplane piece Beginners hard airplanes keeping piece depends type airplane qualityand availabil ity instruction learning ability student degree control instructor has luck Working backward Luck tough control Nasty gusts wind components fail radios cant prevented However amount control instructor has can managed best things RC manu facturing community came up has unfortunately largely discarded buddy box feature Instructors can save lot airplanes being able take control students airplane instantly fumbling shared transmitter buddy-box should used whenever possible/available Lets face students created equal Ive students solo weekend Ive some never will learn fly Most students learn enough solo six eight sessions spread over three- four-week period have decent instructor Continued page 150 PRECISION Hawker Hurricane MI lic $14950 Wing Span 62 inch Weight 61/2 8/2 lbs depends flaps retracts Full Scale Detail includes 5 view flaps retracts setup Engine 65-90 FS 60 TS Fiberglass cowl Aero-Pacer $8900 Sport-Trainer Wing Span 641/2 inch Weight 5-7 Ibs Wing load 19-25 oz Engine 45-65 ES 2945 TS Easily converted tail dragger flaps Video construction tape available BabyPacer $5950 Versatile small size Wing Span 50 inch Weight 25-35 Ibs Wing load 19-25 oz Engine 15-40 ES 19-25 TS ELECTRIC HANDCUT SELECTED BALSA AND HARDWOOD PARTS WITH MADE IN USA QUALITV DH6O Gipsy Moth $10900 Wing Span 541/4 inch Weight 5-6 Lb Wing Load 15 oz Engine 45-65 ES 35-50 TS Flybaby 2 1 Combo Flybaby $7950 Bipe $9500 Combo $11000 Wing Span 56 44 inches Weight 4-5 Ibs Wing Load 22 14 Engine 30-45 ES 25-40 TS AT FIELD CONVERSION 10 MIN l ODROME MODELS LTD OEL5LTD/ L il"2623 S MILLER RD SAGINAW MI 48603 517 781-3000 Limited SupplyTuned Pipe Header 40-45 Size Fits OS 40-45 FSR K&B 40 HP 40 HGK 40-45 Royal-Thunder 7ger-Magnum 40-45 8 Size Fits 05 25-28 FSR K&B Sportster 20 sold stores INCL UDES Tuned Pipe Silencer Header Silicone joint tube Moun tin strop screws pressure top ond am ing wire Please Add $200 P511 per order CA residents odd sales tax RJL Industries 1831 Business Center Dr Duarte CA 91010 818 359-0016 August 198749 VISA Mastercard COD money order Add $550 Post Handling Mich residents add 4% Video Catalog $1000 Beta VHS $5 rebate order Cowls either ABS Fiberglass Plan Packs Available LOG$750 AL 1000s choose Solar rubber powered gliders copters scale lasercut diecut youcut rockets origami some wing span 6 feet ALL MADE OUt OF PAPER Limited number printed 18188423455PAPER AIRPLANES INTERNATIONAL1213822-9185 1521 Morningside Drive Burbank California91506USA Dodgson has new construction videotapes ready shipment Bobs Tape No came out last winter showed beautiful flying shots four planes produces design philos ophy New tape No 2 shows Dave Banks wing construction sequences runs two hours Tape No 3 shows fuselage construction linkage layouts 90 minutes havent seen new tapes Id imagine would invaluable anyone buildingor thinking buildingone Bobs kits refundable deposit $15 $30 $40 depending whether order two three tapes time Shipping handling $10 $15 $20 making total $25 $45 $60 Other news Bob extra $45 will partially pre-build fuselage new Windsong Camano Pixie Formers bulk heads elevator bearings nose wing saddle plywood decking installed rein forced called plans work done jig fuselage locked perfect alignment Bob also says business going great add help get backlog down manageable level Bobs address 21230 Damson Road Bothell WA 98021 phone number 206 776-8067 Valley Forges Fifth Annual Sailplane Contest will held August 15-16 site Valley Forge Signal Seekers flying field near King Prussia PA Sportsman Expert Junior will flown both class D class B both days Hand-Launch class event will flown both days Sport Scale Sunday biggest contests East hear its well-run lot fun CD will Fran Olix also Soaring CD Ehe Nats year info write Fran 764 Alexander Drive Hatfield PA 19440 phone 215 341-6713 day time 361-9516 evenings end column month Id like share contents note sent Mrs Mary Holley addressed Sailplaners expressed sympathy Dwights passing last December Model Soaring large part Dwights life know acknowledgement accomplishments type Champion would mean great deal himas does Bryon Blakeslee 3134 Winnebago Dr Sedalia CO 80135 Please enclose SASE responses SEND SASE FOR LITERATURE SHEETS Its also true instructors created equal Some people can fly own airplanes just fine cant teach others really good instructor can dramatically shorten training time student Now get tough onethe trainer airplane As mentioned earlier key learn ing fly RC keeping airplane piece good student has good instructor buddy-box needs entirely different airplane poor student no instructor powered Glider good choice trainer airplane students slow learners have poor/no instructors and/or no buddy-box type airplane inherently stable can often fly itself out trouble much easier fly land because moves relatively slowly novice pilot has better chance keep up aircrafts motion permits student time evaluate orientation airplane figure out what wing loading usually fairly low often allows survive crashes good shape wouldnt everyone want learn fly using powered Glider Well depending abilities novice pilot instructor availability buddy-box some students will learn lot faster others Pilots seldom use powered Glider type trainer-airplane much radio check airplane after learn fly So move advanced trainer much like airplane other proponents would have recommended start out means investment money long run its wasted pilot can learn fly quickly Having said Id straddle both sides issue must add beginner can decide airplane best satisfies training situation hes found himself Ron Van Putte 111 Sleepy Oaks Rd Ft Walton Beach FL 32548 RC Electrics/Kopski Continued page 51 Part No 4032 priced $6 Cell size just mentioned above since readers experience some confusion difficulty dimension thought Id offer some additional information Before con tinuing may want reference April 87 MA column same subject 36 Cell size generally expressed either ampere-hours milliampere-hours expressions simply refer amount charge cell capable accepting delivering ie big tank electrically As example popular 12 Ah ampere hour cell can expected deliver about 12 amps hour 012 amps 10 hours such total current-time product So sixminute ho-hour motor run flight average motor current would have 12 amperes completely drain cell assuming started fully charged pack because 12 amps x Yo hour mpere-hours course cell capacity can also expressed minutes Thus same 1 2-Ah cellor pack can said have 72 ampere-minute capacity since 60 minutes hour 12 x 60 ust portion size description identifies time-factor can expressed way also can part describes electric current Thus 1 2-Ah example can also described having 1200 milliampere-hour capacity since 1000 milliamperes ampere Miii means 4ooosee July 1985 issue MA Combining above could call example 72000 milliampere-minute cell pack Well little cumbersome routinely used expression However does serve additional illustration idea cell size Great say what use Well lets say wanted fast-charge rather small motor pack Free Flight Electric Lets say using 250-mAh cells wanted charge 15 minutesthe longest period can set time-switch charger question comes up much charge current should used Remember doesnt matter cells areonly cells pack must same size obviously way look question approach realize 250 mAh one-quarter ampere-hour since 250/1000 could charge 1/4 ampere 250 milliamps hourbut thats four individual turns 15-minute hour charger-timer knob Since really want job just timer-knob turn charging has done four times faster Clearly example would charge 4 x 250 mulliamps 4 x amp amp 15 minutes Again 1 amp x 15 minutes p x ere-hour 250/1000 ampere-hour milliampere hours about something uneven Continued page 152 150 Model Aviation r3/4 SCALE CLASSICSHigh Performance Rubber Powered $1795 / KORDA 33___________ DEALER AND DISTRI BUTOR_________ INOUIRES INVITED PLUS 8 MORE RUBBER POWERED MODELS KIT INCLUDES FOLDING PROP MATERIALS SELECT WOODS FULL SIZE PLAN CLOUD 33 R/NmocielsPouox 5059ALAMOGORDO NM 88311 CLODHOPPER RC Aerobatics/Van Putte Continued page 49 responding advertIsers mention read about ModelAviation