El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door 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dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 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Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 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x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. 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Edition: Model Aviation - 1994/12
Page Numbers: 104, 105, 106, 107, 108, 109, 110, 111, 112
El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door 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dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 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Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 1/4xl 5/16 50 3/8 SO 3/8 ul/2 3/8u3/4 3/8xl 1/2 SO 1/2u3/4 1/2xl 5/8 SO 3/4 SO TRAILING EDGE 1/8 xl/2 3/18 x3/4 1/4xl 5/18 u 1-1/14 3/8xl-1/2 1/2x2 1/4x2 1/4x3 3/8x2 3/8x3 1/2x3 3648 10 10 11 15 09 12 13 17 09 1218 1319 1824 1219 1826 1826 2231 2642 3752 1926 2329 2535 3650 4567 2330 3039 3549 4858 5575 4255 5270 6589 5575 7598 36 25 30 35 45 49 79 85 95 79 115 135 UNULtL00ALS 36 201/16x3699 201/16u 41035 203/32x 3875 153/32u4999 151/8u3775 101/8x4775 153/16x3940 103/16n4899 101/4x3765 101/4x41285 103/8u3920 53/8u4835 51/2x3605 5 1/2u41150 BUNDLEDEALS48 10 3/32u4950 51/8x4550 5 3/16x4650 51/4u4735 BALSASHEETS UGHT 44LB3648 1/32u378119 1/20u378119 1/16x378119 3/32u393144 1/8 u3114175 3/16u3132202 1/4 x3157237 3/8 u3188307 1/2 u 3236382 3/4 u3375519 n3532719 1/32x4123188 1/20u4123188 1/16u4123188 3/32n 4149232 1/8 u4169262 3/16x4197300 1/4 x 4237332 3/8 x 4357563 1/2 x4482688 ALL 46 LB WOOD SUBJECT TO AVAILABILITY 3 L1 antn122448 3/32 n6120225430 3/32 12225430750 1/8 u6125245475 1/8 x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. HanOi/no Chero- $000 pa UPS A44 9495 COOINFO & HELPORDERS ONLY24 HR FAXSEND MAILLONE STAR MODELS 9000 extra Ix PP APOPPO anuept trisJo Olsoxoer persorral W8aiC5 xnCOoeI%tax/oTeoaUuxxrrenoyooloMixwxodordee$lO0O806-745-63941-800-687-5555806-745-6483ORDERS TO RI 9 BOX 437 Lubbock TX 79423 110 Model Aviation HANNEL ANALYZER Ri Featured Model Airplane News Model Aviation Flying Models RC Modeler RC product club needs interference frequency control $825 includes S&H contiguous US CO residents add sales tax Call write Dr Jim Hauser Aero Spectra corporation Post Office Box 3021 Boulder Colorado 80307 Tel Fax 303-499-2584 LARGEST SELECTION AAA GRADE CONTEST BALSA SATISFACTION GUARANTEED SHIPPED 100% 36 25 30 35 49 60 115 195 48 08 75 87 95 07 09 99 96 97 110 115 125 902 669 689 669 869 040 185 300 550 1650 200 330 600 1000 365 665 1200 315 675 315 600 199 Appendix Although seldom used since much greater construction effort significantly better see Table III case curved dihedral shape some interest Such shape may either circular curvature constant along span have curvature smallest wing centerline gets progressively larger outboard sketched Figure A-l Probably easiest way determine EVD such curved shape make large-size drawing half wing divide shape several pieces say three B C straight line drawn between ends piece give flat panels dashed lines distances x L angles panels measured per Fig ld procedure same Example 6 using equation EVD B C angles panels B C curved shapes using equal divisions reasonable will seen three divisions enough practical purposes EVD can also calculated tabular manner shown following example uses 10 divisions exceptional accuracy curved shape similar Fig A- 1 has total length measured along curve 30 inches divided 10 equal pieces having length three inches straight line drawn between ends piece representing flat panels half-span L distances x angles panel per Fig 1 d measured L inches values x/L computed corresponding values k obtained Table II items listed first five columns Table A- 1 products k times angle listed sixth column sum column gives EVD practical purposes using three divisions sufficiently accurate calculating EVD can seem Table A-2 EVD 11780 essentially same 11970 obtained using 10 divisions Using two divisions gives 11 490 using gives 100 wing area effectiveness calculated Example 8 96 see Table III item [g] EVD both 10 3 divisions Further Refinements previous methods adequate practical purposes interested further refinements following applicable gull-type wings tapered planforms Gull-Type Wing Dihedral Examples 3 4 covered However since wing panel stops side fuselage New HydriMax batteriesthe first nickel metal hydride NiMH cells packs available R/C usesafely power full day flying charge youve enjoyed convenience using new NiMH-powered laptop computers imagine freedom youll have HydriMax batteries sophisticated transmitters other R/C gear. 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Edition: Model Aviation - 1994/12
Page Numbers: 104, 105, 106, 107, 108, 109, 110, 111, 112
El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door 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dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 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Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 1/4xl 5/16 50 3/8 SO 3/8 ul/2 3/8u3/4 3/8xl 1/2 SO 1/2u3/4 1/2xl 5/8 SO 3/4 SO TRAILING EDGE 1/8 xl/2 3/18 x3/4 1/4xl 5/18 u 1-1/14 3/8xl-1/2 1/2x2 1/4x2 1/4x3 3/8x2 3/8x3 1/2x3 3648 10 10 11 15 09 12 13 17 09 1218 1319 1824 1219 1826 1826 2231 2642 3752 1926 2329 2535 3650 4567 2330 3039 3549 4858 5575 4255 5270 6589 5575 7598 36 25 30 35 45 49 79 85 95 79 115 135 UNULtL00ALS 36 201/16x3699 201/16u 41035 203/32x 3875 153/32u4999 151/8u3775 101/8x4775 153/16x3940 103/16n4899 101/4x3765 101/4x41285 103/8u3920 53/8u4835 51/2x3605 5 1/2u41150 BUNDLEDEALS48 10 3/32u4950 51/8x4550 5 3/16x4650 51/4u4735 BALSASHEETS UGHT 44LB3648 1/32u378119 1/20u378119 1/16x378119 3/32u393144 1/8 u3114175 3/16u3132202 1/4 x3157237 3/8 u3188307 1/2 u 3236382 3/4 u3375519 n3532719 1/32x4123188 1/20u4123188 1/16u4123188 3/32n 4149232 1/8 u4169262 3/16x4197300 1/4 x 4237332 3/8 x 4357563 1/2 x4482688 ALL 46 LB WOOD SUBJECT TO AVAILABILITY 3 L1 antn122448 3/32 n6120225430 3/32 12225430750 1/8 u6125245475 1/8 x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. HanOi/no Chero- $000 pa UPS A44 9495 COOINFO & HELPORDERS ONLY24 HR FAXSEND MAILLONE STAR MODELS 9000 extra Ix PP APOPPO anuept trisJo Olsoxoer persorral W8aiC5 xnCOoeI%tax/oTeoaUuxxrrenoyooloMixwxodordee$lO0O806-745-63941-800-687-5555806-745-6483ORDERS TO RI 9 BOX 437 Lubbock TX 79423 110 Model Aviation HANNEL ANALYZER Ri Featured Model Airplane News Model Aviation Flying Models RC Modeler RC product club needs interference frequency control $825 includes S&H contiguous US CO residents add sales tax Call write Dr Jim Hauser Aero Spectra corporation Post Office Box 3021 Boulder Colorado 80307 Tel Fax 303-499-2584 LARGEST SELECTION AAA GRADE CONTEST BALSA SATISFACTION GUARANTEED SHIPPED 100% 36 25 30 35 49 60 115 195 48 08 75 87 95 07 09 99 96 97 110 115 125 902 669 689 669 869 040 185 300 550 1650 200 330 600 1000 365 665 1200 315 675 315 600 199 Appendix Although seldom used since much greater construction effort significantly better see Table III case curved dihedral shape some interest Such shape may either circular curvature constant along span have curvature smallest wing centerline gets progressively larger outboard sketched Figure A-l Probably easiest way determine EVD such curved shape make large-size drawing half wing divide shape several pieces say three B C straight line drawn between ends piece give flat panels dashed lines distances x L angles panels measured per Fig ld procedure same Example 6 using equation EVD B C angles panels B C curved shapes using equal divisions reasonable will seen three divisions enough practical purposes EVD can also calculated tabular manner shown following example uses 10 divisions exceptional accuracy curved shape similar Fig A- 1 has total length measured along curve 30 inches divided 10 equal pieces having length three inches straight line drawn between ends piece representing flat panels half-span L distances x angles panel per Fig 1 d measured L inches values x/L computed corresponding values k obtained Table II items listed first five columns Table A- 1 products k times angle listed sixth column sum column gives EVD practical purposes using three divisions sufficiently accurate calculating EVD can seem Table A-2 EVD 11780 essentially same 11970 obtained using 10 divisions Using two divisions gives 11 490 using gives 100 wing area effectiveness calculated Example 8 96 see Table III item [g] EVD both 10 3 divisions Further Refinements previous methods adequate practical purposes interested further refinements following applicable gull-type wings tapered planforms Gull-Type Wing Dihedral Examples 3 4 covered However since wing panel stops side fuselage New HydriMax batteriesthe first nickel metal hydride NiMH cells packs available R/C usesafely power full day flying charge youve enjoyed convenience using new NiMH-powered laptop computers imagine freedom youll have HydriMax batteries sophisticated transmitters other R/C gear. HydriMax NiMH batteries double rated capacity ordinary Ix Rx packswithout requiring room bigger cells provide tests have proven DOUBLE safe flight/run time supply greater capacity adding weightideal radio other low medium current applications up 6 Amps AA cells provide 1200 mAh capacity cells provide 1800 mAh capacity extending charge time can use standard radio NiCd chargeror use multi-rate charger like Hobbico RC Multicharger HCAPO1 00 overnight charging Unlike NiCds present no disposal problemsNiMH batteries environmentally safe Choose full range assembled packs tabbed untabbed cells free brochure location dealer nearest please call 1-800-682-8948 ext 044S December1994 111 U 0 St C 3 0 ID 0 St I Ii Tests pertornied soing 96V Fetaba FP-T7UAP transoutter results will vary based actual condilons 0stibutat Exclusively Though GREAT PLANES MODEL OISTRIBOTORO COMPuNY PO Box 0021 Champaign IL 610269021 Jet Propelled Turbojet Sounds Like Real Jet Plane Battery Powered Push-Button Control II FUN TO FLY ERTODYFLYA REAL JET Only S23D Plus S4Q Postage Send Check Money Order Ordert Shinned like Example 5 accurate assume additional inner panel centerline fuselage side has zero dihedral illustrated Figures A-2 A-3 Compare following Examples 3 and4 Fig leand a Inverted Gull Dihedral x1/L k1 x2/L 2 00 B C EVD 00 8O 0 6250 b Gull Dihedral x1/L k1 x2/L 2 97 C EVD grees 30 o 2260 refinement makes inverted gull EVD slightly larger gull EVD smaller Examples 3 4 Effect Tapered Planform EVD previous dihedral data rectangular planforms Tapered planforms result slightly less EVD rectangular ones same span area straight taper Figure A-4 taper ratio TR tip chord divided root chord Ct/Cr EVD determined no taper must multiplied factor F calculated F8 Cr value F always between 10 C C ng having varying taper Fig A-4b elliptical etc considers straight-tapered planform having same area span root chord Cr Its tip chord will C1 alb Cr indicated dashed lines value C used calculate F Finally EVD taper calculated approximately EVDtaper FxEVD Example wing elliptical planform has span 36 inches root chord 6 inches has 150 wing dihedral What its EVD due taper Its area 7tQ6/26/2 square inches therefore 21696/36 6 So F 342/6 914 Finally EVDtaper 914150 So truly elliptical wing planform EVDtapcr EVD Appendix B EVD calculations article based data Table II Other dihedral data results smaller EVD values 1990 NFFS Symposium paper Hewitt Phillips gives considerably larger values especially outer panels having dihedral break x/L greater 50 Table B-I has k values derived paper would like use Note larger values k compared Table II Technical review article done Gil Morris comments Well-presented paper very useful information enjoyed reading Gil also made two suggestions improve text author appreciates comments made changes TE-OF-ThE-ART TECHNOLOGY ATA PRIEYOU CAN APPRECLATE GenesIs state-of-the-art all-composite molded vacuum bagged model designed thermal duration competition Synergy F3B models highly competitive evelything thermal duration slope racing Limited time pricing Genesis $449 Synergy Ill $599 Synergy 91 $549 SB/XC $749 Evolution 2 Meter Now Available $395 Available exclusively Slegers InternatIonal 201 366-0880 RoR Products 1120 Wrigley Way Milpitas CA 95035 946-4751 112 Model Aviation 4Old Engines Restored Runninq Model Engine Trealment Increases Compression $700 Post Paid DOC-ZILLA P 0 Box 111 Jasonville IN 47438
Edition: Model Aviation - 1994/12
Page Numbers: 104, 105, 106, 107, 108, 109, 110, 111, 112
El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door cylinder 5/16 dia 1 inch stroke 8 lb thrust metal body $1900 uP1 Independent speed control & switching struts $2895 UP2Strut & door control Mustangs Door opens strut lowers door closes Door opens strut raises door closes $7465100 INCH MUSTANG RETRACTS 50 LB RATING UP3 Strut & door control valve P47 Door opens-strut lowers-Totally enclosed mechanism-all metal-i inch air cylinder-85 degre door stays open Strut raises-door closes$7465retraction Fits between ribs$57900 including UP2 valve ULTRA PRECISION Technical Services Ltd 1244 Honeysuckle Crescent Oakvi lie OntarioL6H 2S8 Canada Phone 905 1703 Dealer inguirieswelcomeAll prices US fundsShipping valves & cylinders $450 model effective vertical horizontal tail areas effective horizontal tail area must too small effective vertical tail area must too large duration avoid spiral instability troubles requires scale dihedral angle reduced sometimes scale tail area must changed effective horizontal tail area panel S Scos2a actual area panel dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 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SIG MANUFACTURING CO imports the worlds fastest running production engine ROSS! engines performance tested race proven SIG carries engines airplane helicopter car boat also have full-time ROSS REPAIR CENTER talking performance talking ROSS SIG-imported ROSS engines come full 90 day SIG WARRANTY against workmanship manufacturing defects uA- EEE7 EE IG MANUFACTURING CO INC. Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 1/4xl 5/16 50 3/8 SO 3/8 ul/2 3/8u3/4 3/8xl 1/2 SO 1/2u3/4 1/2xl 5/8 SO 3/4 SO TRAILING EDGE 1/8 xl/2 3/18 x3/4 1/4xl 5/18 u 1-1/14 3/8xl-1/2 1/2x2 1/4x2 1/4x3 3/8x2 3/8x3 1/2x3 3648 10 10 11 15 09 12 13 17 09 1218 1319 1824 1219 1826 1826 2231 2642 3752 1926 2329 2535 3650 4567 2330 3039 3549 4858 5575 4255 5270 6589 5575 7598 36 25 30 35 45 49 79 85 95 79 115 135 UNULtL00ALS 36 201/16x3699 201/16u 41035 203/32x 3875 153/32u4999 151/8u3775 101/8x4775 153/16x3940 103/16n4899 101/4x3765 101/4x41285 103/8u3920 53/8u4835 51/2x3605 5 1/2u41150 BUNDLEDEALS48 10 3/32u4950 51/8x4550 5 3/16x4650 51/4u4735 BALSASHEETS UGHT 44LB3648 1/32u378119 1/20u378119 1/16x378119 3/32u393144 1/8 u3114175 3/16u3132202 1/4 x3157237 3/8 u3188307 1/2 u 3236382 3/4 u3375519 n3532719 1/32x4123188 1/20u4123188 1/16u4123188 3/32n 4149232 1/8 u4169262 3/16x4197300 1/4 x 4237332 3/8 x 4357563 1/2 x4482688 ALL 46 LB WOOD SUBJECT TO AVAILABILITY 3 L1 antn122448 3/32 n6120225430 3/32 12225430750 1/8 u6125245475 1/8 x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. HanOi/no Chero- $000 pa UPS A44 9495 COOINFO & HELPORDERS ONLY24 HR FAXSEND MAILLONE STAR MODELS 9000 extra Ix PP APOPPO anuept trisJo Olsoxoer persorral W8aiC5 xnCOoeI%tax/oTeoaUuxxrrenoyooloMixwxodordee$lO0O806-745-63941-800-687-5555806-745-6483ORDERS TO RI 9 BOX 437 Lubbock TX 79423 110 Model Aviation HANNEL ANALYZER Ri Featured Model Airplane News Model Aviation Flying Models RC Modeler RC product club needs interference frequency control $825 includes S&H contiguous US CO residents add sales tax Call write Dr Jim Hauser Aero Spectra corporation Post Office Box 3021 Boulder Colorado 80307 Tel Fax 303-499-2584 LARGEST SELECTION AAA GRADE CONTEST BALSA SATISFACTION GUARANTEED SHIPPED 100% 36 25 30 35 49 60 115 195 48 08 75 87 95 07 09 99 96 97 110 115 125 902 669 689 669 869 040 185 300 550 1650 200 330 600 1000 365 665 1200 315 675 315 600 199 Appendix Although seldom used since much greater construction effort significantly better see Table III case curved dihedral shape some interest Such shape may either circular curvature constant along span have curvature smallest wing centerline gets progressively larger outboard sketched Figure A-l Probably easiest way determine EVD such curved shape make large-size drawing half wing divide shape several pieces say three B C straight line drawn between ends piece give flat panels dashed lines distances x L angles panels measured per Fig ld procedure same Example 6 using equation EVD B C angles panels B C curved shapes using equal divisions reasonable will seen three divisions enough practical purposes EVD can also calculated tabular manner shown following example uses 10 divisions exceptional accuracy curved shape similar Fig A- 1 has total length measured along curve 30 inches divided 10 equal pieces having length three inches straight line drawn between ends piece representing flat panels half-span L distances x angles panel per Fig 1 d measured L inches values x/L computed corresponding values k obtained Table II items listed first five columns Table A- 1 products k times angle listed sixth column sum column gives EVD practical purposes using three divisions sufficiently accurate calculating EVD can seem Table A-2 EVD 11780 essentially same 11970 obtained using 10 divisions Using two divisions gives 11 490 using gives 100 wing area effectiveness calculated Example 8 96 see Table III item [g] EVD both 10 3 divisions Further Refinements previous methods adequate practical purposes interested further refinements following applicable gull-type wings tapered planforms Gull-Type Wing Dihedral Examples 3 4 covered However since wing panel stops side fuselage New HydriMax batteriesthe first nickel metal hydride NiMH cells packs available R/C usesafely power full day flying charge youve enjoyed convenience using new NiMH-powered laptop computers imagine freedom youll have HydriMax batteries sophisticated transmitters other R/C gear. HydriMax NiMH batteries double rated capacity ordinary Ix Rx packswithout requiring room bigger cells provide tests have proven DOUBLE safe flight/run time supply greater capacity adding weightideal radio other low medium current applications up 6 Amps AA cells provide 1200 mAh capacity cells provide 1800 mAh capacity extending charge time can use standard radio NiCd chargeror use multi-rate charger like Hobbico RC Multicharger HCAPO1 00 overnight charging Unlike NiCds present no disposal problemsNiMH batteries environmentally safe Choose full range assembled packs tabbed untabbed cells free brochure location dealer nearest please call 1-800-682-8948 ext 044S December1994 111 U 0 St C 3 0 ID 0 St I Ii Tests pertornied soing 96V Fetaba FP-T7UAP transoutter results will vary based actual condilons 0stibutat Exclusively Though GREAT PLANES MODEL OISTRIBOTORO COMPuNY PO Box 0021 Champaign IL 610269021 Jet Propelled Turbojet Sounds Like Real Jet Plane Battery Powered Push-Button Control II FUN TO FLY ERTODYFLYA REAL JET Only S23D Plus S4Q Postage Send Check Money Order Ordert Shinned like Example 5 accurate assume additional inner panel centerline fuselage side has zero dihedral illustrated Figures A-2 A-3 Compare following Examples 3 and4 Fig leand a Inverted Gull Dihedral x1/L k1 x2/L 2 00 B C EVD 00 8O 0 6250 b Gull Dihedral x1/L k1 x2/L 2 97 C EVD grees 30 o 2260 refinement makes inverted gull EVD slightly larger gull EVD smaller Examples 3 4 Effect Tapered Planform EVD previous dihedral data rectangular planforms Tapered planforms result slightly less EVD rectangular ones same span area straight taper Figure A-4 taper ratio TR tip chord divided root chord Ct/Cr EVD determined no taper must multiplied factor F calculated F8 Cr value F always between 10 C C ng having varying taper Fig A-4b elliptical etc considers straight-tapered planform having same area span root chord Cr Its tip chord will C1 alb Cr indicated dashed lines value C used calculate F Finally EVD taper calculated approximately EVDtaper FxEVD Example wing elliptical planform has span 36 inches root chord 6 inches has 150 wing dihedral What its EVD due taper Its area 7tQ6/26/2 square inches therefore 21696/36 6 So F 342/6 914 Finally EVDtaper 914150 So truly elliptical wing planform EVDtapcr EVD Appendix B EVD calculations article based data Table II Other dihedral data results smaller EVD values 1990 NFFS Symposium paper Hewitt Phillips gives considerably larger values especially outer panels having dihedral break x/L greater 50 Table B-I has k values derived paper would like use Note larger values k compared Table II Technical review article done Gil Morris comments Well-presented paper very useful information enjoyed reading Gil also made two suggestions improve text author appreciates comments made changes TE-OF-ThE-ART TECHNOLOGY ATA PRIEYOU CAN APPRECLATE GenesIs state-of-the-art all-composite molded vacuum bagged model designed thermal duration competition Synergy F3B models highly competitive evelything thermal duration slope racing Limited time pricing Genesis $449 Synergy Ill $599 Synergy 91 $549 SB/XC $749 Evolution 2 Meter Now Available $395 Available exclusively Slegers InternatIonal 201 366-0880 RoR Products 1120 Wrigley Way Milpitas CA 95035 946-4751 112 Model Aviation 4Old Engines Restored Runninq Model Engine Trealment Increases Compression $700 Post Paid DOC-ZILLA P 0 Box 111 Jasonville IN 47438
Edition: Model Aviation - 1994/12
Page Numbers: 104, 105, 106, 107, 108, 109, 110, 111, 112
El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door cylinder 5/16 dia 1 inch stroke 8 lb thrust metal body $1900 uP1 Independent speed control & switching struts $2895 UP2Strut & door control Mustangs Door opens strut lowers door closes Door opens strut raises door closes $7465100 INCH MUSTANG RETRACTS 50 LB RATING UP3 Strut & door control valve P47 Door opens-strut lowers-Totally enclosed mechanism-all metal-i inch air cylinder-85 degre door stays open Strut raises-door closes$7465retraction Fits between ribs$57900 including UP2 valve ULTRA PRECISION Technical Services Ltd 1244 Honeysuckle Crescent Oakvi lie OntarioL6H 2S8 Canada Phone 905 1703 Dealer inguirieswelcomeAll prices US fundsShipping valves & cylinders $450 model effective vertical horizontal tail areas effective horizontal tail area must too small effective vertical tail area must too large duration avoid spiral instability troubles requires scale dihedral angle reduced sometimes scale tail area must changed effective horizontal tail area panel S Scos2a actual area panel dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 4 STROKE HEAD LOCK REMOTE product designed use cowled engines helicopters boats cars general safety removing glow plug connector close proximity whirling propeller REMOTE unit consists miniature HEAD LOCK connector remote jack electrically coupled 12 inches teflon insulated wire 12 inch ground lead bracket supplied jack convenient mounting JACK compatible HEAD LOCK connectors St #021 Single $995 St #022 Twin $1395 available write direct add $1 00 $200 outside US 108 Model Aviation WJGEE ONE OF THE MANY THINGS IN THIS WORLD THAT CANT BE BEAT! SIG MANUFACTURING CO imports the worlds fastest running production engine ROSS! engines performance tested race proven SIG carries engines airplane helicopter car boat also have full-time ROSS REPAIR CENTER talking performance talking ROSS SIG-imported ROSS engines come full 90 day SIG WARRANTY against workmanship manufacturing defects uA- EEE7 EE IG MANUFACTURING CO INC. Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 1/4xl 5/16 50 3/8 SO 3/8 ul/2 3/8u3/4 3/8xl 1/2 SO 1/2u3/4 1/2xl 5/8 SO 3/4 SO TRAILING EDGE 1/8 xl/2 3/18 x3/4 1/4xl 5/18 u 1-1/14 3/8xl-1/2 1/2x2 1/4x2 1/4x3 3/8x2 3/8x3 1/2x3 3648 10 10 11 15 09 12 13 17 09 1218 1319 1824 1219 1826 1826 2231 2642 3752 1926 2329 2535 3650 4567 2330 3039 3549 4858 5575 4255 5270 6589 5575 7598 36 25 30 35 45 49 79 85 95 79 115 135 UNULtL00ALS 36 201/16x3699 201/16u 41035 203/32x 3875 153/32u4999 151/8u3775 101/8x4775 153/16x3940 103/16n4899 101/4x3765 101/4x41285 103/8u3920 53/8u4835 51/2x3605 5 1/2u41150 BUNDLEDEALS48 10 3/32u4950 51/8x4550 5 3/16x4650 51/4u4735 BALSASHEETS UGHT 44LB3648 1/32u378119 1/20u378119 1/16x378119 3/32u393144 1/8 u3114175 3/16u3132202 1/4 x3157237 3/8 u3188307 1/2 u 3236382 3/4 u3375519 n3532719 1/32x4123188 1/20u4123188 1/16u4123188 3/32n 4149232 1/8 u4169262 3/16x4197300 1/4 x 4237332 3/8 x 4357563 1/2 x4482688 ALL 46 LB WOOD SUBJECT TO AVAILABILITY 3 L1 antn122448 3/32 n6120225430 3/32 12225430750 1/8 u6125245475 1/8 x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. HanOi/no Chero- $000 pa UPS A44 9495 COOINFO & HELPORDERS ONLY24 HR FAXSEND MAILLONE STAR MODELS 9000 extra Ix PP APOPPO anuept trisJo Olsoxoer persorral W8aiC5 xnCOoeI%tax/oTeoaUuxxrrenoyooloMixwxodordee$lO0O806-745-63941-800-687-5555806-745-6483ORDERS TO RI 9 BOX 437 Lubbock TX 79423 110 Model Aviation HANNEL ANALYZER Ri Featured Model Airplane News Model Aviation Flying Models RC Modeler RC product club needs interference frequency control $825 includes S&H contiguous US CO residents add sales tax Call write Dr Jim Hauser Aero Spectra corporation Post Office Box 3021 Boulder Colorado 80307 Tel Fax 303-499-2584 LARGEST SELECTION AAA GRADE CONTEST BALSA SATISFACTION GUARANTEED SHIPPED 100% 36 25 30 35 49 60 115 195 48 08 75 87 95 07 09 99 96 97 110 115 125 902 669 689 669 869 040 185 300 550 1650 200 330 600 1000 365 665 1200 315 675 315 600 199 Appendix Although seldom used since much greater construction effort significantly better see Table III case curved dihedral shape some interest Such shape may either circular curvature constant along span have curvature smallest wing centerline gets progressively larger outboard sketched Figure A-l Probably easiest way determine EVD such curved shape make large-size drawing half wing divide shape several pieces say three B C straight line drawn between ends piece give flat panels dashed lines distances x L angles panels measured per Fig ld procedure same Example 6 using equation EVD B C angles panels B C curved shapes using equal divisions reasonable will seen three divisions enough practical purposes EVD can also calculated tabular manner shown following example uses 10 divisions exceptional accuracy curved shape similar Fig A- 1 has total length measured along curve 30 inches divided 10 equal pieces having length three inches straight line drawn between ends piece representing flat panels half-span L distances x angles panel per Fig 1 d measured L inches values x/L computed corresponding values k obtained Table II items listed first five columns Table A- 1 products k times angle listed sixth column sum column gives EVD practical purposes using three divisions sufficiently accurate calculating EVD can seem Table A-2 EVD 11780 essentially same 11970 obtained using 10 divisions Using two divisions gives 11 490 using gives 100 wing area effectiveness calculated Example 8 96 see Table III item [g] EVD both 10 3 divisions Further Refinements previous methods adequate practical purposes interested further refinements following applicable gull-type wings tapered planforms Gull-Type Wing Dihedral Examples 3 4 covered However since wing panel stops side fuselage New HydriMax batteriesthe first nickel metal hydride NiMH cells packs available R/C usesafely power full day flying charge youve enjoyed convenience using new NiMH-powered laptop computers imagine freedom youll have HydriMax batteries sophisticated transmitters other R/C gear. HydriMax NiMH batteries double rated capacity ordinary Ix Rx packswithout requiring room bigger cells provide tests have proven DOUBLE safe flight/run time supply greater capacity adding weightideal radio other low medium current applications up 6 Amps AA cells provide 1200 mAh capacity cells provide 1800 mAh capacity extending charge time can use standard radio NiCd chargeror use multi-rate charger like Hobbico RC Multicharger HCAPO1 00 overnight charging Unlike NiCds present no disposal problemsNiMH batteries environmentally safe Choose full range assembled packs tabbed untabbed cells free brochure location dealer nearest please call 1-800-682-8948 ext 044S December1994 111 U 0 St C 3 0 ID 0 St I Ii Tests pertornied soing 96V Fetaba FP-T7UAP transoutter results will vary based actual condilons 0stibutat Exclusively Though GREAT PLANES MODEL OISTRIBOTORO COMPuNY PO Box 0021 Champaign IL 610269021 Jet Propelled Turbojet Sounds Like Real Jet Plane Battery Powered Push-Button Control II FUN TO FLY ERTODYFLYA REAL JET Only S23D Plus S4Q Postage Send Check Money Order Ordert Shinned like Example 5 accurate assume additional inner panel centerline fuselage side has zero dihedral illustrated Figures A-2 A-3 Compare following Examples 3 and4 Fig leand a Inverted Gull Dihedral x1/L k1 x2/L 2 00 B C EVD 00 8O 0 6250 b Gull Dihedral x1/L k1 x2/L 2 97 C EVD grees 30 o 2260 refinement makes inverted gull EVD slightly larger gull EVD smaller Examples 3 4 Effect Tapered Planform EVD previous dihedral data rectangular planforms Tapered planforms result slightly less EVD rectangular ones same span area straight taper Figure A-4 taper ratio TR tip chord divided root chord Ct/Cr EVD determined no taper must multiplied factor F calculated F8 Cr value F always between 10 C C ng having varying taper Fig A-4b elliptical etc considers straight-tapered planform having same area span root chord Cr Its tip chord will C1 alb Cr indicated dashed lines value C used calculate F Finally EVD taper calculated approximately EVDtaper FxEVD Example wing elliptical planform has span 36 inches root chord 6 inches has 150 wing dihedral What its EVD due taper Its area 7tQ6/26/2 square inches therefore 21696/36 6 So F 342/6 914 Finally EVDtaper 914150 So truly elliptical wing planform EVDtapcr EVD Appendix B EVD calculations article based data Table II Other dihedral data results smaller EVD values 1990 NFFS Symposium paper Hewitt Phillips gives considerably larger values especially outer panels having dihedral break x/L greater 50 Table B-I has k values derived paper would like use Note larger values k compared Table II Technical review article done Gil Morris comments Well-presented paper very useful information enjoyed reading Gil also made two suggestions improve text author appreciates comments made changes TE-OF-ThE-ART TECHNOLOGY ATA PRIEYOU CAN APPRECLATE GenesIs state-of-the-art all-composite molded vacuum bagged model designed thermal duration competition Synergy F3B models highly competitive evelything thermal duration slope racing Limited time pricing Genesis $449 Synergy Ill $599 Synergy 91 $549 SB/XC $749 Evolution 2 Meter Now Available $395 Available exclusively Slegers InternatIonal 201 366-0880 RoR Products 1120 Wrigley Way Milpitas CA 95035 946-4751 112 Model Aviation 4Old Engines Restored Runninq Model Engine Trealment Increases Compression $700 Post Paid DOC-ZILLA P 0 Box 111 Jasonville IN 47438
Edition: Model Aviation - 1994/12
Page Numbers: 104, 105, 106, 107, 108, 109, 110, 111, 112
El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door cylinder 5/16 dia 1 inch stroke 8 lb thrust metal body $1900 uP1 Independent speed control & switching struts $2895 UP2Strut & door control Mustangs Door opens strut lowers door closes Door opens strut raises door closes $7465100 INCH MUSTANG RETRACTS 50 LB RATING UP3 Strut & door control valve P47 Door opens-strut lowers-Totally enclosed mechanism-all metal-i inch air cylinder-85 degre door stays open Strut raises-door closes$7465retraction Fits between ribs$57900 including UP2 valve ULTRA PRECISION Technical Services Ltd 1244 Honeysuckle Crescent Oakvi lie OntarioL6H 2S8 Canada Phone 905 1703 Dealer inguirieswelcomeAll prices US fundsShipping valves & cylinders $450 model effective vertical horizontal tail areas effective horizontal tail area must too small effective vertical tail area must too large duration avoid spiral instability troubles requires scale dihedral angle reduced sometimes scale tail area must changed effective horizontal tail area panel S Scos2a actual area panel dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 4 STROKE HEAD LOCK REMOTE product designed use cowled engines helicopters boats cars general safety removing glow plug connector close proximity whirling propeller REMOTE unit consists miniature HEAD LOCK connector remote jack electrically coupled 12 inches teflon insulated wire 12 inch ground lead bracket supplied jack convenient mounting JACK compatible HEAD LOCK connectors St #021 Single $995 St #022 Twin $1395 available write direct add $1 00 $200 outside US 108 Model Aviation WJGEE ONE OF THE MANY THINGS IN THIS WORLD THAT CANT BE BEAT! SIG MANUFACTURING CO imports the worlds fastest running production engine ROSS! engines performance tested race proven SIG carries engines airplane helicopter car boat also have full-time ROSS REPAIR CENTER talking performance talking ROSS SIG-imported ROSS engines come full 90 day SIG WARRANTY against workmanship manufacturing defects uA- EEE7 EE IG MANUFACTURING CO INC. Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 1/4xl 5/16 50 3/8 SO 3/8 ul/2 3/8u3/4 3/8xl 1/2 SO 1/2u3/4 1/2xl 5/8 SO 3/4 SO TRAILING EDGE 1/8 xl/2 3/18 x3/4 1/4xl 5/18 u 1-1/14 3/8xl-1/2 1/2x2 1/4x2 1/4x3 3/8x2 3/8x3 1/2x3 3648 10 10 11 15 09 12 13 17 09 1218 1319 1824 1219 1826 1826 2231 2642 3752 1926 2329 2535 3650 4567 2330 3039 3549 4858 5575 4255 5270 6589 5575 7598 36 25 30 35 45 49 79 85 95 79 115 135 UNULtL00ALS 36 201/16x3699 201/16u 41035 203/32x 3875 153/32u4999 151/8u3775 101/8x4775 153/16x3940 103/16n4899 101/4x3765 101/4x41285 103/8u3920 53/8u4835 51/2x3605 5 1/2u41150 BUNDLEDEALS48 10 3/32u4950 51/8x4550 5 3/16x4650 51/4u4735 BALSASHEETS UGHT 44LB3648 1/32u378119 1/20u378119 1/16x378119 3/32u393144 1/8 u3114175 3/16u3132202 1/4 x3157237 3/8 u3188307 1/2 u 3236382 3/4 u3375519 n3532719 1/32x4123188 1/20u4123188 1/16u4123188 3/32n 4149232 1/8 u4169262 3/16x4197300 1/4 x 4237332 3/8 x 4357563 1/2 x4482688 ALL 46 LB WOOD SUBJECT TO AVAILABILITY 3 L1 antn122448 3/32 n6120225430 3/32 12225430750 1/8 u6125245475 1/8 x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. HanOi/no Chero- $000 pa UPS A44 9495 COOINFO & HELPORDERS ONLY24 HR FAXSEND MAILLONE STAR MODELS 9000 extra Ix PP APOPPO anuept trisJo Olsoxoer persorral W8aiC5 xnCOoeI%tax/oTeoaUuxxrrenoyooloMixwxodordee$lO0O806-745-63941-800-687-5555806-745-6483ORDERS TO RI 9 BOX 437 Lubbock TX 79423 110 Model Aviation HANNEL ANALYZER Ri Featured Model Airplane News Model Aviation Flying Models RC Modeler RC product club needs interference frequency control $825 includes S&H contiguous US CO residents add sales tax Call write Dr Jim Hauser Aero Spectra corporation Post Office Box 3021 Boulder Colorado 80307 Tel Fax 303-499-2584 LARGEST SELECTION AAA GRADE CONTEST BALSA SATISFACTION GUARANTEED SHIPPED 100% 36 25 30 35 49 60 115 195 48 08 75 87 95 07 09 99 96 97 110 115 125 902 669 689 669 869 040 185 300 550 1650 200 330 600 1000 365 665 1200 315 675 315 600 199 Appendix Although seldom used since much greater construction effort significantly better see Table III case curved dihedral shape some interest Such shape may either circular curvature constant along span have curvature smallest wing centerline gets progressively larger outboard sketched Figure A-l Probably easiest way determine EVD such curved shape make large-size drawing half wing divide shape several pieces say three B C straight line drawn between ends piece give flat panels dashed lines distances x L angles panels measured per Fig ld procedure same Example 6 using equation EVD B C angles panels B C curved shapes using equal divisions reasonable will seen three divisions enough practical purposes EVD can also calculated tabular manner shown following example uses 10 divisions exceptional accuracy curved shape similar Fig A- 1 has total length measured along curve 30 inches divided 10 equal pieces having length three inches straight line drawn between ends piece representing flat panels half-span L distances x angles panel per Fig 1 d measured L inches values x/L computed corresponding values k obtained Table II items listed first five columns Table A- 1 products k times angle listed sixth column sum column gives EVD practical purposes using three divisions sufficiently accurate calculating EVD can seem Table A-2 EVD 11780 essentially same 11970 obtained using 10 divisions Using two divisions gives 11 490 using gives 100 wing area effectiveness calculated Example 8 96 see Table III item [g] EVD both 10 3 divisions Further Refinements previous methods adequate practical purposes interested further refinements following applicable gull-type wings tapered planforms Gull-Type Wing Dihedral Examples 3 4 covered However since wing panel stops side fuselage New HydriMax batteriesthe first nickel metal hydride NiMH cells packs available R/C usesafely power full day flying charge youve enjoyed convenience using new NiMH-powered laptop computers imagine freedom youll have HydriMax batteries sophisticated transmitters other R/C gear. 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Edition: Model Aviation - 1994/12
Page Numbers: 104, 105, 106, 107, 108, 109, 110, 111, 112
El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door 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dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 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SIG MANUFACTURING CO imports the worlds fastest running production engine ROSS! engines performance tested race proven SIG carries engines airplane helicopter car boat also have full-time ROSS REPAIR CENTER talking performance talking ROSS SIG-imported ROSS engines come full 90 day SIG WARRANTY against workmanship manufacturing defects uA- EEE7 EE IG MANUFACTURING CO INC. Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 1/4xl 5/16 50 3/8 SO 3/8 ul/2 3/8u3/4 3/8xl 1/2 SO 1/2u3/4 1/2xl 5/8 SO 3/4 SO TRAILING EDGE 1/8 xl/2 3/18 x3/4 1/4xl 5/18 u 1-1/14 3/8xl-1/2 1/2x2 1/4x2 1/4x3 3/8x2 3/8x3 1/2x3 3648 10 10 11 15 09 12 13 17 09 1218 1319 1824 1219 1826 1826 2231 2642 3752 1926 2329 2535 3650 4567 2330 3039 3549 4858 5575 4255 5270 6589 5575 7598 36 25 30 35 45 49 79 85 95 79 115 135 UNULtL00ALS 36 201/16x3699 201/16u 41035 203/32x 3875 153/32u4999 151/8u3775 101/8x4775 153/16x3940 103/16n4899 101/4x3765 101/4x41285 103/8u3920 53/8u4835 51/2x3605 5 1/2u41150 BUNDLEDEALS48 10 3/32u4950 51/8x4550 5 3/16x4650 51/4u4735 BALSASHEETS UGHT 44LB3648 1/32u378119 1/20u378119 1/16x378119 3/32u393144 1/8 u3114175 3/16u3132202 1/4 x3157237 3/8 u3188307 1/2 u 3236382 3/4 u3375519 n3532719 1/32x4123188 1/20u4123188 1/16u4123188 3/32n 4149232 1/8 u4169262 3/16x4197300 1/4 x 4237332 3/8 x 4357563 1/2 x4482688 ALL 46 LB WOOD SUBJECT TO AVAILABILITY 3 L1 antn122448 3/32 n6120225430 3/32 12225430750 1/8 u6125245475 1/8 x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. HanOi/no Chero- $000 pa UPS A44 9495 COOINFO & HELPORDERS ONLY24 HR FAXSEND MAILLONE STAR MODELS 9000 extra Ix PP APOPPO anuept trisJo Olsoxoer persorral W8aiC5 xnCOoeI%tax/oTeoaUuxxrrenoyooloMixwxodordee$lO0O806-745-63941-800-687-5555806-745-6483ORDERS TO RI 9 BOX 437 Lubbock TX 79423 110 Model Aviation HANNEL ANALYZER Ri Featured Model Airplane News Model Aviation Flying Models RC Modeler RC product club needs interference frequency control $825 includes S&H contiguous US CO residents add sales tax Call write Dr Jim Hauser Aero Spectra corporation Post Office Box 3021 Boulder Colorado 80307 Tel Fax 303-499-2584 LARGEST SELECTION AAA GRADE CONTEST BALSA SATISFACTION GUARANTEED SHIPPED 100% 36 25 30 35 49 60 115 195 48 08 75 87 95 07 09 99 96 97 110 115 125 902 669 689 669 869 040 185 300 550 1650 200 330 600 1000 365 665 1200 315 675 315 600 199 Appendix Although seldom used since much greater construction effort significantly better see Table III case curved dihedral shape some interest Such shape may either circular curvature constant along span have curvature smallest wing centerline gets progressively larger outboard sketched Figure A-l Probably easiest way determine EVD such curved shape make large-size drawing half wing divide shape several pieces say three B C straight line drawn between ends piece give flat panels dashed lines distances x L angles panels measured per Fig ld procedure same Example 6 using equation EVD B C angles panels B C curved shapes using equal divisions reasonable will seen three divisions enough practical purposes EVD can also calculated tabular manner shown following example uses 10 divisions exceptional accuracy curved shape similar Fig A- 1 has total length measured along curve 30 inches divided 10 equal pieces having length three inches straight line drawn between ends piece representing flat panels half-span L distances x angles panel per Fig 1 d measured L inches values x/L computed corresponding values k obtained Table II items listed first five columns Table A- 1 products k times angle listed sixth column sum column gives EVD practical purposes using three divisions sufficiently accurate calculating EVD can seem Table A-2 EVD 11780 essentially same 11970 obtained using 10 divisions Using two divisions gives 11 490 using gives 100 wing area effectiveness calculated Example 8 96 see Table III item [g] EVD both 10 3 divisions Further Refinements previous methods adequate practical purposes interested further refinements following applicable gull-type wings tapered planforms Gull-Type Wing Dihedral Examples 3 4 covered However since wing panel stops side fuselage New HydriMax batteriesthe first nickel metal hydride NiMH cells packs available R/C usesafely power full day flying charge youve enjoyed convenience using new NiMH-powered laptop computers imagine freedom youll have HydriMax batteries sophisticated transmitters other R/C gear. HydriMax NiMH batteries double rated capacity ordinary Ix Rx packswithout requiring room bigger cells provide tests have proven DOUBLE safe flight/run time supply greater capacity adding weightideal radio other low medium current applications up 6 Amps AA cells provide 1200 mAh capacity cells provide 1800 mAh capacity extending charge time can use standard radio NiCd chargeror use multi-rate charger like Hobbico RC Multicharger HCAPO1 00 overnight charging Unlike NiCds present no disposal problemsNiMH batteries environmentally safe Choose full range assembled packs tabbed untabbed cells free brochure location dealer nearest please call 1-800-682-8948 ext 044S December1994 111 U 0 St C 3 0 ID 0 St I Ii Tests pertornied soing 96V Fetaba FP-T7UAP transoutter results will vary based actual condilons 0stibutat Exclusively Though GREAT PLANES MODEL OISTRIBOTORO COMPuNY PO Box 0021 Champaign IL 610269021 Jet Propelled Turbojet Sounds Like Real Jet Plane Battery Powered Push-Button Control II FUN TO FLY ERTODYFLYA REAL JET Only S23D Plus S4Q Postage Send Check Money Order Ordert Shinned like Example 5 accurate assume additional inner panel centerline fuselage side has zero dihedral illustrated Figures A-2 A-3 Compare following Examples 3 and4 Fig leand a Inverted Gull Dihedral x1/L k1 x2/L 2 00 B C EVD 00 8O 0 6250 b Gull Dihedral x1/L k1 x2/L 2 97 C EVD grees 30 o 2260 refinement makes inverted gull EVD slightly larger gull EVD smaller Examples 3 4 Effect Tapered Planform EVD previous dihedral data rectangular planforms Tapered planforms result slightly less EVD rectangular ones same span area straight taper Figure A-4 taper ratio TR tip chord divided root chord Ct/Cr EVD determined no taper must multiplied factor F calculated F8 Cr value F always between 10 C C ng having varying taper Fig A-4b elliptical etc considers straight-tapered planform having same area span root chord Cr Its tip chord will C1 alb Cr indicated dashed lines value C used calculate F Finally EVD taper calculated approximately EVDtaper FxEVD Example wing elliptical planform has span 36 inches root chord 6 inches has 150 wing dihedral What its EVD due taper Its area 7tQ6/26/2 square inches therefore 21696/36 6 So F 342/6 914 Finally EVDtaper 914150 So truly elliptical wing planform EVDtapcr EVD Appendix B EVD calculations article based data Table II Other dihedral data results smaller EVD values 1990 NFFS Symposium paper Hewitt Phillips gives considerably larger values especially outer panels having dihedral break x/L greater 50 Table B-I has k values derived paper would like use Note larger values k compared Table II Technical review article done Gil Morris comments Well-presented paper very useful information enjoyed reading Gil also made two suggestions improve text author appreciates comments made changes TE-OF-ThE-ART TECHNOLOGY ATA PRIEYOU CAN APPRECLATE GenesIs state-of-the-art all-composite molded vacuum bagged model designed thermal duration competition Synergy F3B models highly competitive evelything thermal duration slope racing Limited time pricing Genesis $449 Synergy Ill $599 Synergy 91 $549 SB/XC $749 Evolution 2 Meter Now Available $395 Available exclusively Slegers InternatIonal 201 366-0880 RoR Products 1120 Wrigley Way Milpitas CA 95035 946-4751 112 Model Aviation 4Old Engines Restored Runninq Model Engine Trealment Increases Compression $700 Post Paid DOC-ZILLA P 0 Box 111 Jasonville IN 47438
Edition: Model Aviation - 1994/12
Page Numbers: 104, 105, 106, 107, 108, 109, 110, 111, 112
El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door 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dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 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Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 1/4xl 5/16 50 3/8 SO 3/8 ul/2 3/8u3/4 3/8xl 1/2 SO 1/2u3/4 1/2xl 5/8 SO 3/4 SO TRAILING EDGE 1/8 xl/2 3/18 x3/4 1/4xl 5/18 u 1-1/14 3/8xl-1/2 1/2x2 1/4x2 1/4x3 3/8x2 3/8x3 1/2x3 3648 10 10 11 15 09 12 13 17 09 1218 1319 1824 1219 1826 1826 2231 2642 3752 1926 2329 2535 3650 4567 2330 3039 3549 4858 5575 4255 5270 6589 5575 7598 36 25 30 35 45 49 79 85 95 79 115 135 UNULtL00ALS 36 201/16x3699 201/16u 41035 203/32x 3875 153/32u4999 151/8u3775 101/8x4775 153/16x3940 103/16n4899 101/4x3765 101/4x41285 103/8u3920 53/8u4835 51/2x3605 5 1/2u41150 BUNDLEDEALS48 10 3/32u4950 51/8x4550 5 3/16x4650 51/4u4735 BALSASHEETS UGHT 44LB3648 1/32u378119 1/20u378119 1/16x378119 3/32u393144 1/8 u3114175 3/16u3132202 1/4 x3157237 3/8 u3188307 1/2 u 3236382 3/4 u3375519 n3532719 1/32x4123188 1/20u4123188 1/16u4123188 3/32n 4149232 1/8 u4169262 3/16x4197300 1/4 x 4237332 3/8 x 4357563 1/2 x4482688 ALL 46 LB WOOD SUBJECT TO AVAILABILITY 3 L1 antn122448 3/32 n6120225430 3/32 12225430750 1/8 u6125245475 1/8 x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. HanOi/no Chero- $000 pa UPS A44 9495 COOINFO & HELPORDERS ONLY24 HR FAXSEND MAILLONE STAR MODELS 9000 extra Ix PP APOPPO anuept trisJo Olsoxoer persorral W8aiC5 xnCOoeI%tax/oTeoaUuxxrrenoyooloMixwxodordee$lO0O806-745-63941-800-687-5555806-745-6483ORDERS TO RI 9 BOX 437 Lubbock TX 79423 110 Model Aviation HANNEL ANALYZER Ri Featured Model Airplane News Model Aviation Flying Models RC Modeler RC product club needs interference frequency control $825 includes S&H contiguous US CO residents add sales tax Call write Dr Jim Hauser Aero Spectra corporation Post Office Box 3021 Boulder Colorado 80307 Tel Fax 303-499-2584 LARGEST SELECTION AAA GRADE CONTEST BALSA SATISFACTION GUARANTEED SHIPPED 100% 36 25 30 35 49 60 115 195 48 08 75 87 95 07 09 99 96 97 110 115 125 902 669 689 669 869 040 185 300 550 1650 200 330 600 1000 365 665 1200 315 675 315 600 199 Appendix Although seldom used since much greater construction effort significantly better see Table III case curved dihedral shape some interest Such shape may either circular curvature constant along span have curvature smallest wing centerline gets progressively larger outboard sketched Figure A-l Probably easiest way determine EVD such curved shape make large-size drawing half wing divide shape several pieces say three B C straight line drawn between ends piece give flat panels dashed lines distances x L angles panels measured per Fig ld procedure same Example 6 using equation EVD B C angles panels B C curved shapes using equal divisions reasonable will seen three divisions enough practical purposes EVD can also calculated tabular manner shown following example uses 10 divisions exceptional accuracy curved shape similar Fig A- 1 has total length measured along curve 30 inches divided 10 equal pieces having length three inches straight line drawn between ends piece representing flat panels half-span L distances x angles panel per Fig 1 d measured L inches values x/L computed corresponding values k obtained Table II items listed first five columns Table A- 1 products k times angle listed sixth column sum column gives EVD practical purposes using three divisions sufficiently accurate calculating EVD can seem Table A-2 EVD 11780 essentially same 11970 obtained using 10 divisions Using two divisions gives 11 490 using gives 100 wing area effectiveness calculated Example 8 96 see Table III item [g] EVD both 10 3 divisions Further Refinements previous methods adequate practical purposes interested further refinements following applicable gull-type wings tapered planforms Gull-Type Wing Dihedral Examples 3 4 covered However since wing panel stops side fuselage New HydriMax batteriesthe first nickel metal hydride NiMH cells packs available R/C usesafely power full day flying charge youve enjoyed convenience using new NiMH-powered laptop computers imagine freedom youll have HydriMax batteries sophisticated transmitters other R/C gear. HydriMax NiMH batteries double rated capacity ordinary Ix Rx packswithout requiring room bigger cells provide tests have proven DOUBLE safe flight/run time supply greater capacity adding weightideal radio other low medium current applications up 6 Amps AA cells provide 1200 mAh capacity cells provide 1800 mAh capacity extending charge time can use standard radio NiCd chargeror use multi-rate charger like Hobbico RC Multicharger HCAPO1 00 overnight charging Unlike NiCds present no disposal problemsNiMH batteries environmentally safe Choose full range assembled packs tabbed untabbed cells free brochure location dealer nearest please call 1-800-682-8948 ext 044S December1994 111 U 0 St C 3 0 ID 0 St I Ii Tests pertornied soing 96V Fetaba FP-T7UAP transoutter results will vary based actual condilons 0stibutat Exclusively Though GREAT PLANES MODEL OISTRIBOTORO COMPuNY PO Box 0021 Champaign IL 610269021 Jet Propelled Turbojet Sounds Like Real Jet Plane Battery Powered Push-Button Control II FUN TO FLY ERTODYFLYA REAL JET Only S23D Plus S4Q Postage Send Check Money Order Ordert Shinned like Example 5 accurate assume additional inner panel centerline fuselage side has zero dihedral illustrated Figures A-2 A-3 Compare following Examples 3 and4 Fig leand a Inverted Gull Dihedral x1/L k1 x2/L 2 00 B C EVD 00 8O 0 6250 b Gull Dihedral x1/L k1 x2/L 2 97 C EVD grees 30 o 2260 refinement makes inverted gull EVD slightly larger gull EVD smaller Examples 3 4 Effect Tapered Planform EVD previous dihedral data rectangular planforms Tapered planforms result slightly less EVD rectangular ones same span area straight taper Figure A-4 taper ratio TR tip chord divided root chord Ct/Cr EVD determined no taper must multiplied factor F calculated F8 Cr value F always between 10 C C ng having varying taper Fig A-4b elliptical etc considers straight-tapered planform having same area span root chord Cr Its tip chord will C1 alb Cr indicated dashed lines value C used calculate F Finally EVD taper calculated approximately EVDtaper FxEVD Example wing elliptical planform has span 36 inches root chord 6 inches has 150 wing dihedral What its EVD due taper Its area 7tQ6/26/2 square inches therefore 21696/36 6 So F 342/6 914 Finally EVDtaper 914150 So truly elliptical wing planform EVDtapcr EVD Appendix B EVD calculations article based data Table II Other dihedral data results smaller EVD values 1990 NFFS Symposium paper Hewitt Phillips gives considerably larger values especially outer panels having dihedral break x/L greater 50 Table B-I has k values derived paper would like use Note larger values k compared Table II Technical review article done Gil Morris comments Well-presented paper very useful information enjoyed reading Gil also made two suggestions improve text author appreciates comments made changes TE-OF-ThE-ART TECHNOLOGY ATA PRIEYOU CAN APPRECLATE GenesIs state-of-the-art all-composite molded vacuum bagged model designed thermal duration competition Synergy F3B models highly competitive evelything thermal duration slope racing Limited time pricing Genesis $449 Synergy Ill $599 Synergy 91 $549 SB/XC $749 Evolution 2 Meter Now Available $395 Available exclusively Slegers InternatIonal 201 366-0880 RoR Products 1120 Wrigley Way Milpitas CA 95035 946-4751 112 Model Aviation 4Old Engines Restored Runninq Model Engine Trealment Increases Compression $700 Post Paid DOC-ZILLA P 0 Box 111 Jasonville IN 47438
Edition: Model Aviation - 1994/12
Page Numbers: 104, 105, 106, 107, 108, 109, 110, 111, 112
El THE PURPOSE OF wing dihedral return model its proper trimmed attitude after has upset laterally banked disturbance such gusty air improper launch model may trimmed either wings-level wings-banked flight upset laterally wingtip will drop model will begin sideslip downward direction sideslipping airflow generates slightly larger lift lower wing slightly smaller lift higher wing rolls model back its proper attitude wings level wings-banked dihedral faster occurs good since results less lost altitude too much dihedral bad since effective lifting area wing reduced too much Therefore duration capability reasonable amount necessary depends type model amount dihedral restricted contest rules FF duration models generous amounts used FF Scale models using scale dihedral results scale penalty increases excess dihedral increases Most full-scale airplanes have little no wing dihedral since hurts airplanes flying qualities such slowing down rate roll etc Hence FF Scale models have much less wing dihedral FF duration models therefore recover quickly lateral upsets such small scale dihedral used especially important vertical tail too large Figure 1 4L 1 la V-Dihedral Duration Models & Real Airplanes ic Polyhedral 3 Breaks Duration Models l4 L X744 le Inverted Gull Dihedral Real Airplanes eg Vought F4U Corsair 4~1 B 0 ib Outer Panel Dihedral Duration Models & Real Airplanes eg Jodel D-9 14 L x2 xl C AB id Polyhedral 5 Breaks Duration Models 4 L Xr4--1AB Gull Dihedral Real Airplanes eg Hall Bulldog because sideslipping sideward airflow pushes tail sideward causing model turn therefore roll sideslip opposes good effect dihedral slowing recovery large enough will overcome causing spiral dive cannot prevented trim changes such rudder sidethrust incidence changes Too large tail will also prevent high-powered FF gas rubber model being able steadily climb very steeply straight up causing persistently roll off undesired shallower spiraling flight results less altitude duration cannot prevented trim changes detailed discussion data proper small vertical tail size FF duration FF Scale models see article Vertical Tail Size Models Ref March April 1992 issues Model Aviation book Ref B recommended end article have proper amount wing dihedral must determine what proper amount particular model b much dihedral does model actually have determine things generally best modelers purposes express both required actual dihedral terms simple V-dihedral Fig la Required Equivalent V-Dihedral Since Table 1 Type model Equivalent V-Dihedral Nordic towline glider 12O Hand-launched glider 17o Indoor rubber 60 Outdoor rubber 1150 Gas-power duration 15o FF5 high wing0 30 FF5 mid wing* 0 FFS biplane* 40 FFS low wing0 80 RC aileronsSee RO discussion RO aileronsSee RC discussion *Use scale dihedral larger Also see text 104 Model Aviation s wing dihedral described later helpful express terms equivalent V-dihedral EVD express required dihedral terms reviews amounts dihedral used successful models various types will found summarized Table shows range within fall method determining EVD presented later FF Scale models tries use scale dihedral very close often adequateparticularly vertical tail sufficiently small small vertical tail minimum acceptable wing dihedral FF Scale model depends effective dihedral due other things such wing position high low wing aspect ratio wingtip slant sweepback discussed detail referenced Table II article larger tail larger minimum acceptable wing dihedral becomes no spiral instability troubles practical test adequate minimum FF Scale dihedral launched forward gliding speed just above head height wings banked 400 model should roll out its banked attitude before lands model must trimmed straight slow glide before doing event necessary dihedral type model decided Table other sources model made equal follows Types Wing Dihedral five main types wing dihedral used models real airplanes shown Figure 1 simplest having dihedral break b next simplest having two breaks c e f have three breaks d has five applications models xIL 0IO5I1015I20I25f303540I45I50I55I60I65I70I75I80I85I90I1 k 1 99 98 97 96 93 90 84 79 73 66 59 52 45 38 31 24 18 11 0 Data NACA report 1098 Table III Wing Area Type DihedralEffectiveness 100120140160 aV-Dihedral97969492 bOuter Panel Dihedral x/L 69493 cOuter Panel Dihedral x/L 59189 dPolyhedral x/L 3A97969593 ePolyhedral x/L 3A97969492 fPolyhedral x1IL 33 x2/L 6797969593 B C gCircular Curved Dihedral97969593 Figure F-lb full-scale airplanes noted Note carefully various dihedral angles measured dihedral angles positive pt angle e angle B f negative - since measured downward reference lines Note angle B Fig ib measured horizontal cases b c e f equivalent V-dihedral EVD calculated following simple formula EVD case [d] see Example 6 B known angles degrees factor k obtained Table II L half-span wing its dihedral installed x distance centerline out dihedral break x/L calculated enter Table II Examples calculating EVD shown later calculated EVD large desired EVD per Table angle and/or angle B increased until calculated value adequate vice-versa calculated value too large dihedral starts just slightly outboard wings centerline FF Scale models usually starts side fuselage x/L usually small enough dihedral can simply considered V-dihedral ie start centerline see Example 5 following examples note angles positive except Example 3 B Example 4 Figure 2 Table IV B102030405060708090100110120 sin B017035052070087105122139156174191208 B130140150160170180190200210220230240 sin B225242259276292309326342358375391407 B2502602702802903Q03504Q0450500 sin B 423438454469485500574643707766 December 1994 105 a4Q0 Bh h bxsinB Figure A-i b Varying Curvature C -I I A- Example Calculations 1 A wing outer panel dihedral Fig Ib has x/L herefore EVD 52140 2 A wing polyhedral Fig ic has xfL herefore EVD 45200 3 An inverted gull wing Fig le has B x/L15 Therefore EVD 97250 4 A gull wing Fig lf has B xIL15 Therefore EVD 97420 5 This example case FF Scale models wing dihedral starts side fuselage /L ess Therefore EVD 9740 EVD close 40 can simply considered V-dihedral rather outer-panel dihedral such models 6 Polyhedral like Fig id seldom seen since much work build Its EVD would calculated BYD k1 obtained x1/L k2 x2/L Table II example x1 ches x2 nches L nches x1/L 2IL able Ilk1 2 41 EVD EVD 40 B VD EVD 8860 0 same procedure would used number dihedral breaks 7 case continuous curved dihedral seldom used see Appendix examples can easily compute EVD dihedral scheme see provides what desired per Table other sources Effective Wing Tail Area effective wing area contributing lift decreases wing dihedral increases obviously fully effective dihedral zero zero dihedral angle 900 always less so-called projected area commonly used comparisons fact becomes particularly important dihedral angle quite large V-tails example effective lifting area panel dihedral calculated 5eff 2a S actual area panel angle between panel horizontal Note measured like outer dihedral angles ie relative adjacent inner panel always horizontal example Fig ld angle outer panel C 8 Fig lc assume actual area inner panel 65 square inches outer panel 35 square inches xfL 65 angle 60 B 190 Table A-2 Panel Anglexx/LkkAngle A3330 13330 B66709983398535680 0667019856754152770 EVD 0 Figure A-2 plus text formula Figure A-3 text formula Table A-i Figure A-4 0rTRC -Y a Straight Taper Equivalent straight taper Tb Varying Taper Table B-I xIL 0105110115120 125 30 I35140145150I55160165170175180185190195 110 k 1 105 108 108 106 105 101 97 92 87 81 74 68 61 54 47 40 32 25 16 0 106 Model Aviation verted Gull Dihedral AC BXiIL 065 k1 X2IL 15 k2 97 0 8 18o 0250 EVD 98718o 0 6250 b Gull Dihedral 4J X2 4 ziJ7L 075 k1 985 IX2/L 15 k2 97 I/ 0 B 4300 420 EVD 985430 o 2260 Panel Anglexx/LkkAngle A1000 11000 B203001029801960 C206002049601920 D208983058941790 E2011964077821560 F2014925076501300 G2017876085091020 H202078707370 202369806234 470 J202656903106 210 EVD 0 60 inner panel 60 250 outer panel Seff s2 6 s2 250 287 930 square inches Since actual area 65 100 square inches area effectiveness 93Aoo 3% projected area would use cos instead cos2a would give effectiveness 964too large Table III shows comparison area effectiveness wings having same planform same EVD different types dihedral effectiveness shown EVDs 10 12 14 16 degrees smaller effectiveness means less duration capability Except c differences between types dihedral wing area effectiveness minor f g greater construction effort Therefore b d e practical choices As EVD made smaller effectivenesses increases differences between decrease vice versa EVD made larger Appendix shows EVD effectiveness calculated g Setting Dihedral Angles set dihedral angle panel end raised certain amount h panels length b desired angle B required distance h h sinB Fig Fib sinB given Table IV can retrieved trigonometry tables angles listed can cosB used later V-Tails Some airplanes have so-called V-tails Figure 2 since requires two surfaces instead three provide function vertical horizontal tails Examples Beechcraft Bonanza Davis DA-2A course also requires mechanical coupling elevons what conventional rudder elevator dihedral angle such surface usually about 400 important things FF Scale December 1994 107 See us WRAMS REALISTIC MOTION RETRACT CONTROL VALVES See us Show Lower level valves feature exhaust speed control Toledo Show have expanded range retract control valves cover needsThese valves work standard servos door sequancing done inside valve speed control throw away troublesome restrictors NEW ATTENTION SPRING AIR OWNERS can now have indep endant speed control up down speeds new UP5valve$289 5 NEW NEW Secondary door control valve UP4 used conjunction UP2 valve will provide control tail-wheel doors MUSTANGS secondary doors need stay open g ear down though main doors closedsuch B25 $74495 NEW 7/16 dia DOOR CYLINDERS un stroke 13 lbthrust metal body $2185 NEW Door 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dihedral angle Therefore total effective horizontal tail area 2Scos2 effective vertical tail area panel Ssin2a total effective vertical tail area 2Ssin2a required effective vertical tail area FF Scale models usually small see referenced article dihedral angle must significantly reduced 2Ssin2a gives proper amount effective horizontal tail area calculated see reasonably large suggested Ref B large enough tail area must increased angle again reduced enough give proper effective vertical tail areaa successivetrials procedure airplanes dihedral angle should reduced 40 about 300 less duration capability although scale deviation Example 9 Assume following Scale models V-tail Dihedral Panel area quare inches reqd vertical tail area per referenced article uare inches required horizontal tail area quare inches per referenced book models effective vertical tail area 5eff 215sin2 40 215413 124 square inches too large RemotePAT 4221452 NA7eA eJ FITS ALL STANDARD PLUGS FROM K&B 2 STROKE 1ILJLO ENYA 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Montezuma Iowa 50171 PH 515 623 5154 FAX 515-623-3922 Toll Free Orders 800-247-5008 Modelers Hot Line 800-524-7805 MODEL PRODUCTS CORP PO BOX 100 ALLAMUCHY NJ 07820 908 850-1508 Reduce dihedral angle 310 215sin2 310 215265 796 square inches OK Check horizontal tail area Seff 215cos2 310 215735 2205 square inches OK horizontal tail area too small panel area would increased angle reduced give required vertical tail areaa successive-trials procedure Once constructed effective vertical tail area would changed changing dihedral angle same procedure would used FF duration model discussed next Although frequently used V-tails will serve well best FF duration modelsgas rubber gliderbut dihedral angle must kept small same reasons discussed Scale model actually better use negative dihedral cathedral since will provide positive dihedral rolling effect model upset laterally tends go turning flight proper dihedral angle small gives necessary small effective vertical tail area discussed referenced article just conventional vertical tail FF duration models turn glide trimmed tilting tail conventional tails FF Scale models done canting tail tip forward and/or adjustable elevons tabs latter can done fine-tune powered-flight turn FF duration models primarily set side thrust done conventional vertical tails Tilted tails applicable FF Scale models RC Models amount dihedral needed depends whether ailerons needed best maneuverability ailerons little no wing dihedral 049- 15NEW Electric Lazy Bee Quantum 20 26 4-cycle Delightful Leapin electric radiocontrol performance 0 Makes Excellent Electric Ideal Small Fieldsltsta-offs Imps rollsandhasal2 • Wingtuading 4- 10 az/sq ft Sprung Landing Gearminute duration 6-cell battery pack SeAiflgLe Bell VIfl giCLANCY AVIATIONElectric Lazy Bee Kit $60 NEWI FRentournewvideoforjust$1620% morewingthanoriginal $10 refunded return219W 2nd AVENUELazy Bee Catalogs -$2 Free orderMESA AZ 85210-1317Original Lazy Bee Kit $54 Prices Include Shipping 49-1534Lazy Bee Float Kit -$24 December 1994 109 60 logos lettenng availableno assemblyl 131 RAVENWOOD RD VERSAILLES KY 40383 2 minutes Later ThATS RIGHT THE LAZY BEE CONVERTS FROM LAND PLANE TO SEA PLANE IN JUST 2 MINUTES best Actually total effective dihedral important mentioned previously under Required Equivalent V-Dihedral Without ailerons some significant dihedral needed avoid spiral stability troubles needed good turning banking rolling actually barrel-roll ability case roll produced rudder deflection effect dihedral sufficient speed better understand what happening flight its helpful realize inverted flight wing dihedral becomes cathedral high wing becomes low wing changes effective dihedral airplane RC Models Ailerons case just real airplanes too much total effective dihedral hurts rolling turning maneuverability airplane such requiring better coordination rudder ailerons slowing down rate-of-roll making airplane too sensitive roll small rudder deflections etc best maneuverability essentially no effective dihedral best midwing configuration terms wing dihedral means about 00 20 high wings 00 midwings biplanes 00 20 low wings course RC Scale models should have what real airplanes using closer above can often improve maneuverability RC Models Without Ailerons good rolling turning maneuverability about 90 total effective dihedral needed reasons discussed above terms wing dihedral means about 50 70 high wings 70 80 mid wings biplanes 100 110 low wings differences due wing position significant forward fuselage width depth estimating effective dihedral see referenced article book Scale models above amounts mean scale deviation wing dihedral best maneuverability guides data examples article can easily determine proper amount wing tail dihedral FF model also sure selected type dihedral provides efficient manner Having following referenced article book enables other things easily quickly Ref Vertical Tail Size Models Model Aviation MarchApril 1992 reprints available address below $295 two-stamp SASE Ref B Making Scale Model Airplanes Fly 1994 revision AircraftData Box 763576 Dallas TX 75224 $1495 postage paid BALSASH6US 2040 1/32x23344 1/16u23344 3/32x24053 1/8 x24357 3/lBs 25065 1/4 u26079 3/8 u238 42 78105 1/2 u295125 1/32u333 45 3953 1/20 n 333 45 3953 1/16u333 45 3953 3/32 uS39 54 4760 1/8 u347 65 5775 3/16x355 75 6890 1/4 x370 100 85115 5/16n398135 3/8 u395 130 102150 1/2 u3115 155 135180 3/4 x3199270 1/32 x 450 70 5979 1/20u4St 70 5979 1/16u450 70 5979 3/32 x 459 90 7398 1/8 x468 100 83115 3/ltx478 120 97135 114 u495 136 135155 5/16u4162203 3/8 u4145 214 185247 1/2 u 4209 270 249290 WINGSKINS 3036 1/20n 12479535 1/lOx 12479535 3/32u 12579645 MATCHED SHEETS 4248 3/32x4109125 1/8 x4129148 3/18x4144165 1/4 x4155178 SEND $100 FOR COMPLETE CATALOG BALSA STICKS 1/16 SO 1/16 u 1/4 1/16u3/8 1/16 xI/2 3132 50 3/32 ul/4 3/32u3/8 3/32 ul/2 1/8 SO 1/8x 1/4 1/8x3/8 1/6xl/2 3/1650 3/16x 1/4 3/16x3/8 3/16xl/2 3/16o3/4 3/16xl 1/4 SO 1/4u3/8 1/401/2 1/4x3/4 1/4xl 5/16 50 3/8 SO 3/8 ul/2 3/8u3/4 3/8xl 1/2 SO 1/2u3/4 1/2xl 5/8 SO 3/4 SO TRAILING EDGE 1/8 xl/2 3/18 x3/4 1/4xl 5/18 u 1-1/14 3/8xl-1/2 1/2x2 1/4x2 1/4x3 3/8x2 3/8x3 1/2x3 3648 10 10 11 15 09 12 13 17 09 1218 1319 1824 1219 1826 1826 2231 2642 3752 1926 2329 2535 3650 4567 2330 3039 3549 4858 5575 4255 5270 6589 5575 7598 36 25 30 35 45 49 79 85 95 79 115 135 UNULtL00ALS 36 201/16x3699 201/16u 41035 203/32x 3875 153/32u4999 151/8u3775 101/8x4775 153/16x3940 103/16n4899 101/4x3765 101/4x41285 103/8u3920 53/8u4835 51/2x3605 5 1/2u41150 BUNDLEDEALS48 10 3/32u4950 51/8x4550 5 3/16x4650 51/4u4735 BALSASHEETS UGHT 44LB3648 1/32u378119 1/20u378119 1/16x378119 3/32u393144 1/8 u3114175 3/16u3132202 1/4 x3157237 3/8 u3188307 1/2 u 3236382 3/4 u3375519 n3532719 1/32x4123188 1/20u4123188 1/16u4123188 3/32n 4149232 1/8 u4169262 3/16x4197300 1/4 x 4237332 3/8 x 4357563 1/2 x4482688 ALL 46 LB WOOD SUBJECT TO AVAILABILITY 3 L1 antn122448 3/32 n6120225430 3/32 12225430750 1/8 u6125245475 1/8 x12245475835 1/4 u6105215345 1/4 12215345650 3/8 x6130240450 3/8 12240475850 1/2 u6175295490 1/2 x12295495970 SUPERIORLITE2448 1/8 x8150285 18x12285550 LITEPLY122448 1/BuB 75110175 1/8 12110190350 1/4u6 95155275 1/4x 12155295550 2mm & 25mm ume price 1/8 3 PLY BIRCH 122448 1/64u6 125235439 1/64x12 235439850 1/32x6 95159299 1/32u 12 180299550 1/16x6 95159209 1/18u 12 180299550 1/8 u6 95159299 1/8 u12 180299550 4 PLY BIRCH 122448 3/16u 6109 215 315 3/16u 12215 345 625 HARD MAPLE 18 1/4u1/440 1/4x3/845 l/4x1/250 3/8x3/845 3/8x1/250 3/8x3/458 3/8x185 3/8x 1-1/2 1/2xl/2 1/2u3/4 5/8x 3/4 3/4x3/4 GROOVED LG MOUNTS 3/8u3/41/8 3/8u3/45/32 1/2u3/43/18 SPRUCE/BASS36 1/16ul/418 3/321/420 1/850 /8xl/4u20 1/8x3/822 1/801/230 1/8x3/442 3/185028 3/16u3/833 3/16xt/2Lu43 3/16u3/4Nss 1/450c34 1/4u3/840 1/4ul/21-.45 1/4u3/4P70 3/850 /0u 1/260 1/2S0.68 1/2n3/475 SPRUCE TRIANGLES 3/8 3/8 1/2 u 1/2 3/4x 1/4 BIRCH DOWELS 1/8 3/16 1/4 5/16 3/8 18 98 65 88 75 82 12 45 45 50 48 25 26 25 26 32 40 55 38 44 57 74 50 55 85 93 69 77 88 97 36 47 64 81 38 14 17 19 25 35 TRIANGLES 1/4xl/4 3/8x3/8 1/2ul/2 3/4u3/4 1xi 1-l/2u 1-1/2 2u2 AILERONS36 1/4 xl40 1/4 ul-1/455 1/4 ul-1/262 1/4 u268 5/16u 1-1/462 5/16u 1-1/264 5/16u272 3/8 u11/468 3/8 uI-1/270 3/8 u279 1/2 uI-I/280 1/2 u200 EPOXY4-1/2OZ 5 Minute425 15 Minute425 30 Minute425 2 Hour425 20 Minute429 INSTANT GLUE 1/2 ax Thin OF 1 uz Thin OF 2 Thin OF 8 nz Thin OF 1/2xx Eutra Thick oz Eutra Thick 2 oz Eutra Thick 8 ox Eutra Thick GOOBLE8iE0B1AM 1/2 oz Thin OF 1 oz Thin OF 2ozThinorGF 2oo Accelerator lOox Acc Refill 3oz Acc No Freon tO oz ACO REF No Freon 1 uz Debonden CunI 4$ Old. HanOi/no Chero- $000 pa UPS A44 9495 COOINFO & HELPORDERS ONLY24 HR FAXSEND MAILLONE STAR MODELS 9000 extra Ix PP APOPPO anuept trisJo Olsoxoer persorral W8aiC5 xnCOoeI%tax/oTeoaUuxxrrenoyooloMixwxodordee$lO0O806-745-63941-800-687-5555806-745-6483ORDERS TO RI 9 BOX 437 Lubbock TX 79423 110 Model Aviation HANNEL ANALYZER Ri Featured Model Airplane News Model Aviation Flying Models RC Modeler RC product club needs interference frequency control $825 includes S&H contiguous US CO residents add sales tax Call write Dr Jim Hauser Aero Spectra corporation Post Office Box 3021 Boulder Colorado 80307 Tel Fax 303-499-2584 LARGEST SELECTION AAA GRADE CONTEST BALSA SATISFACTION GUARANTEED SHIPPED 100% 36 25 30 35 49 60 115 195 48 08 75 87 95 07 09 99 96 97 110 115 125 902 669 689 669 869 040 185 300 550 1650 200 330 600 1000 365 665 1200 315 675 315 600 199 Appendix Although seldom used since much greater construction effort significantly better see Table III case curved dihedral shape some interest Such shape may either circular curvature constant along span have curvature smallest wing centerline gets progressively larger outboard sketched Figure A-l Probably easiest way determine EVD such curved shape make large-size drawing half wing divide shape several pieces say three B C straight line drawn between ends piece give flat panels dashed lines distances x L angles panels measured per Fig ld procedure same Example 6 using equation EVD B C angles panels B C curved shapes using equal divisions reasonable will seen three divisions enough practical purposes EVD can also calculated tabular manner shown following example uses 10 divisions exceptional accuracy curved shape similar Fig A- 1 has total length measured along curve 30 inches divided 10 equal pieces having length three inches straight line drawn between ends piece representing flat panels half-span L distances x angles panel per Fig 1 d measured L inches values x/L computed corresponding values k obtained Table II items listed first five columns Table A- 1 products k times angle listed sixth column sum column gives EVD practical purposes using three divisions sufficiently accurate calculating EVD can seem Table A-2 EVD 11780 essentially same 11970 obtained using 10 divisions Using two divisions gives 11 490 using gives 100 wing area effectiveness calculated Example 8 96 see Table III item [g] EVD both 10 3 divisions Further Refinements previous methods adequate practical purposes interested further refinements following applicable gull-type wings tapered planforms Gull-Type Wing Dihedral Examples 3 4 covered However since wing panel stops side fuselage New HydriMax batteriesthe first nickel metal hydride NiMH cells packs available R/C usesafely power full day flying charge youve enjoyed convenience using new NiMH-powered laptop computers imagine freedom youll have HydriMax batteries sophisticated transmitters other R/C gear. HydriMax NiMH batteries double rated capacity ordinary Ix Rx packswithout requiring room bigger cells provide tests have proven DOUBLE safe flight/run time supply greater capacity adding weightideal radio other low medium current applications up 6 Amps AA cells provide 1200 mAh capacity cells provide 1800 mAh capacity extending charge time can use standard radio NiCd chargeror use multi-rate charger like Hobbico RC Multicharger HCAPO1 00 overnight charging Unlike NiCds present no disposal problemsNiMH batteries environmentally safe Choose full range assembled packs tabbed untabbed cells free brochure location dealer nearest please call 1-800-682-8948 ext 044S December1994 111 U 0 St C 3 0 ID 0 St I Ii Tests pertornied soing 96V Fetaba FP-T7UAP transoutter results will vary based actual condilons 0stibutat Exclusively Though GREAT PLANES MODEL OISTRIBOTORO COMPuNY PO Box 0021 Champaign IL 610269021 Jet Propelled Turbojet Sounds Like Real Jet Plane Battery Powered Push-Button Control II FUN TO FLY ERTODYFLYA REAL JET Only S23D Plus S4Q Postage Send Check Money Order Ordert Shinned like Example 5 accurate assume additional inner panel centerline fuselage side has zero dihedral illustrated Figures A-2 A-3 Compare following Examples 3 and4 Fig leand a Inverted Gull Dihedral x1/L k1 x2/L 2 00 B C EVD 00 8O 0 6250 b Gull Dihedral x1/L k1 x2/L 2 97 C EVD grees 30 o 2260 refinement makes inverted gull EVD slightly larger gull EVD smaller Examples 3 4 Effect Tapered Planform EVD previous dihedral data rectangular planforms Tapered planforms result slightly less EVD rectangular ones same span area straight taper Figure A-4 taper ratio TR tip chord divided root chord Ct/Cr EVD determined no taper must multiplied factor F calculated F8 Cr value F always between 10 C C ng having varying taper Fig A-4b elliptical etc considers straight-tapered planform having same area span root chord Cr Its tip chord will C1 alb Cr indicated dashed lines value C used calculate F Finally EVD taper calculated approximately EVDtaper FxEVD Example wing elliptical planform has span 36 inches root chord 6 inches has 150 wing dihedral What its EVD due taper Its area 7tQ6/26/2 square inches therefore 21696/36 6 So F 342/6 914 Finally EVDtaper 914150 So truly elliptical wing planform EVDtapcr EVD Appendix B EVD calculations article based data Table II Other dihedral data results smaller EVD values 1990 NFFS Symposium paper Hewitt Phillips gives considerably larger values especially outer panels having dihedral break x/L greater 50 Table B-I has k values derived paper would like use Note larger values k compared Table II Technical review article done Gil Morris comments Well-presented paper very useful information enjoyed reading Gil also made two suggestions improve text author appreciates comments made changes TE-OF-ThE-ART TECHNOLOGY ATA PRIEYOU CAN APPRECLATE GenesIs state-of-the-art all-composite molded vacuum bagged model designed thermal duration competition Synergy F3B models highly competitive evelything thermal duration slope racing Limited time pricing Genesis $449 Synergy Ill $599 Synergy 91 $549 SB/XC $749 Evolution 2 Meter Now Available $395 Available exclusively Slegers InternatIonal 201 366-0880 RoR Products 1120 Wrigley Way Milpitas CA 95035 946-4751 112 Model Aviation 4Old Engines Restored Runninq Model Engine Trealment Increases Compression $700 Post Paid DOC-ZILLA P 0 Box 111 Jasonville IN 47438