MIDWEST RIC Models Give choose . theres Midwest model almost kind R/C flyer de sires q5 400 South Indiana St Hobart IndIana 46342 Letters Editor letters will carefully considered general interest used Send Model Aviation 815 15th St NW Washington DC 20005 Sniffer Ive just finished reading Openers column April 1977 issue Mode Aviation read what say about Midwests Sniffer kit P 58 just couldnt believe read over again make sure wasnt seeing wrong see Ive modeling about 2 years now Super Sniffer 48 span first second model airplane decided try balsawood model walked local hobbyshop expecting buy small rubberband powered type owner asked lot questions interests financial status spare time available etc recom mended Super Sniffer Well said told easy build cheap rank beginner should have little trouble getting fly make long story little shorter built flew Cox Baby Bee what con vinced take up modeling After few extremely successful flights decided no matter what did couldnt keep drifting wind thought maybe could afford put cheap radio bring back closer field Chased darned thing 3 miles once Circle climb-circle glide-S mph wind Thats troub les started Nobody told about CG control surface area didnt have instructor pulse single channel expe rience Well first bit dust shortly thereafter knew fault Sniffers started reading some model magazines knew could make plane fly properly single-channel radio proceeded build second Super Sniffer first blue white dope tissue awfully hard see against blue sky got smart lazy results shown enclosed picture Monokote second used ORC 049 really appreciate Soft ears about 1 year old has successful flights recently sold complete outfit some local kids having lot fun thats end story have plans will soon building two Super Sniffersone free flight time dether malizer w/micro 2 ch flight pack f/f will back traditional tis sue dope intend use trans parent Monokote RC Now point letter think talking about Sniffer 37 span Super Sniffer aside size same airplane Ive tried vain find out about history model have run blank stares might able help telling get ahold Wally Sim mers someone else share some experiences model currently am flying some sailplanes am Rocky Mountain Soaring Association compete regularly Sniffer model has got much character think Ill always have around will recom mend beginner Although dont think Midwest doing justice no advertising getting difficult buy hobbyshops truly believe Sniffer enjoy able kits person can have Hey thanks shot arm ego Bill Thomas Fort Collins CO Sniffer described kitted shortly after war 049 un doubtedly smaller referred Thomas Wally Simmers S K&S Engineering 6917 W S9th St Chi cago IL 60638 interesting note good design kit sage dealers advice produced new modeler became RCer Still Props June issue published letter Mr Sidwell regarding timed speeds Formula 1 racer comment high speeds probably due error timing undoubtedly correct would have increase available power 40% go 165 187 mph mention Prather 8 X 6 prop reminded some theoretical cal culations did some months ago what size prop would best newer engines view higher rpm lower torque values maximum power output Using information available time calculations suggested 8 X 6 would best around within about 3% diameter value Prather prop can readily ex plained slight difference dynamic solidity between Prather prop 6 Model Aviation ATTACKER All-molded styrofoam airplane goes gether fast Rugged its great sport plane easy-to-fly advanced trainer Big 48 span powered 19- 35-size engines 4 chan nels Complete hardware package Designed Jim NewmanKit No 134 SUPER CHIPMUNK ARF injection-molded foam 10 19 en gines Wing span 46 Three channels En gine throttle elevator ailerons Four channels Engine throttle elevator ailerons rudder Kit No 126 STR 1K EMASTE R Wing span 55 inches Engine sizes 19 40 Foam wing cores balsa oevering material sup plied Balsa plywood fuselage die cut Balsa sheet fin stabilizer machine cut fittings hardware formed wire parts sup plied Designed Jim Newman Kit No 130 model used calculation purposes used 24000 rpm arrive ideal prop will recall Mr deBolts article May 1977 issue conditions supposed limit maximum speed about 118 mph 80% efficiency Consid ering speed lost turns true 118 mph max Formula 1 plane using Series 2 Prather prop 24000 rpm would seem noncompetitive Formula 1 other hand Vortex Theory made calculations cor rect maximum speed should 145-150 mph range 100% currently held notion efficiency modeling circles Since theory practical experience always agree would like ask would publish hopes some racers using 6 inch prop would re spond giving following information I What best race times prop 2 What ground rpm turn 3 How miles think actually travelled times reported 4 What air rpm think get answers verify calculations would glad work up article two propeller efficiency clear up propeller mystery whole thing can reduced single equation un like Mrs Watsons outverse yaw- equa tion really works engine flight speed reduction ratio etc modeler might encounter imagine J L Brownlec 2407 Quince Drive SE Decatur AL 35601 Mr Brownlees full address given facilitate correspondence important matter Perhaps someday well know about fickle fans Incidentally did spec fically state Mr Sid wells speeds result timing error Mr Brownlee does say probably Still Props Subject Hal deBolts article making Continued page 84 Fox Fuel Line Models Life Blood Passes Through Simple Piece Fuel Line Surely Want Best As engine manufacturers acutely aware large portion called engine problems reality fuel line problems Symptoms fuel line trouble going lean air leaks speed fluctuations inability get rich enough high speed restricted flow Fox Fuel Lines best materials available physical proper ties selected model use Fox Fuel Lines worlds finest Tuff Line Silicone far strongest market semi transparent shows bubbles line heat resis tant Like silicone tubing tends slip off fittings unless care taken Neoprene Actually complex compound much elastic clings fittings main disadvan tage transparent Surgical Tubing Pure Rubber Very flexible Use sharp bends necessary Semi-transparent Shows bubbles line Holds fittings well Main disadvantage tends deteriorate rapidly silicone neoprene Plastic good anybodys dont think much plastic fuel line Advantage low price transparency Disadvantage tends collapse bends hardens age heat Tends leak air fittings after ITEM FUEL LINEPRICEITEM FUEL UNEPRICE 86880 Small Neoprene2 P8g.5086885 Small Clear Pluatic2 Pkg.25 86881 Medium Neoprene2 P8g.6086886 Medium Clear Plantic2/2 P8g.30 86882 Large Neoprene2 P8g7086887 Large Clear Plastic2 P8g.40 86883 Small Tuft Line1 Pkg. 5586888 Small Surgical Tubing2 P8g.50 86884 Medium Tuft Line1 Pkg.7086889 Med Surgical Tubing2 P8g.50 86851 Large Taft Line1 P8g10086890 Large Surgical Tubing2 Pkg.60 FOX MANUFACTURING Fox Model Airplane Products 5305 Towson Smith Arkansas 72901 e 501-646-1656 Answer iWo-Channel Dilemma NIMBUS 2-channel radio system offers American engineering import prices Features include. 1 Solid state superheterodyne 2 All silicon transistor receiver circuit highly selective front end 3 RF amplifier maximum signal noise ratio unexcelled selectivity 4 2 ultra small EK SM servos greater 4 pounds output thrust 5 Receiver servos equipped 3 pin Deans gold plated plugs 6 Adjustable tension control sticks full line brochure write EK-PRODUCTS INC 3322 Stovall St Irving Texas 75061 USA Distributors dealers contact us new merchandising program 1977 EK-Prod.cts nc 779 EK-Products September 1978 7 MORE FIRST PLACE WINNERS AT THE 1977 NATIONALS THAN THE OTHER MAJOR MANUFACTURERS COMBINED IN FACT OVER THE PAST 10 YEARS MORE NAT IONALS WINNERS HAVE USED REV-UP PROPS THAN ANY OTHER BRAND Rev-Up better 1 The efficient design con stant upgrading testing program 2 B4tter quality control better selection hard maple wood 3 The best finish completely fuelproof New Improved 1978 DIAPITCHPRICE 5%34as 63489 733/4119 83 3%456 129 8A77%139 a4565A 77%139 104567149 106W SW149 10SEW159 114677% 7%7%8159 11eEW1e9 ii67189 126179 125W179 1356239 1456279 1556349 164%6449 1756599 1856599 W WIDE BLADE EW EXTRA WIDE SERIES 400 B POE SPEED NG ADVANCED DESIGN ND 1 IN PYLON RACING LEADING SPEED RECORD HOLDER OF ALL TIMES RC pv LON RACING DIAPITCHPRICE 53%4129 756149 7SN SN149 6%6% 6% 7 7%7%159 977% 7%169 CONTROL LINE SPEED& RACING DIA PITCHPRICE 4%6%7129 4%55%129 6 788%149 77%10%11169 689189 89N 9%N189 91213229 N NARROW wide formed leading edge such way cambered airfoil results Formed did say seems Midwest going manufacture kit book kit can recommended together dealer kit course contains shaped leading edge piece Midwest aware FOs sneak preview can say boys have religion Its daring imaginiative approach powered glider hotshots idea trainer must impressed revelations field testing involved very young kids Since two channels required rud der elevator flier involved four very natural stick move ments slow rate climb takes ever get ship real altitude no pressure new flier Control demands presented flier about pace molasses flow ing uphill January 11-year-old boy merely told what stick move ments launched model its first flight come down grass hadnt pushed hard enough launch second flight snagged wing tip grass cartwheeled damage third flight flew ship unaided 9minute flight Mountains words books kits magazines have shoved ginner yet problem big ever knows maybe guys have answer Letters Editor continued page 7 high performance propellers June 78 vol 4 #6 p 30 though pylon racers whatever are out province found deBolts article interesting provocative came away few misgivings think idea presented identical pitch can maintained substituting different types airfoils can very misleading can lead easily specious reasoning Determining pitch some arbitrary datum line seems largely matter choice merely lends itself fiat driving face standard pro peller section would think meaningful approach case would calculate pitch zero lift angle blade airfoil Since could much six seven degrees dif ference zero lift angles between sym metrical airfoil thick flat bottomed section would have big difference aerodynamic pitch also So does leave us would suggest setting propeller blade elements given lift coefficients design advance angles let pitch take care itself As point interest regarding use symmetrical airfoils propeller design recall NACA tests Navy pro peller speedy biconvex airfoil outer fifty percent developing standard airfoil inboard combination gave very high maximum efficiency climb acceleration poor Hal states widest part blade should near 6r station developed view planform seems put much closer hub would interested know came conclusion confuse issue mind NACA propeller compar ison test against standard propeller look ing much like Hals propeller giving highest maximum efficiency its max imum width around 38r nearly straight taper rounded tip gain 3% believe 3% gain propeller efficiency means 1% gain flight speed taken aback fact Hal turning nine inch diameter prop 27K common occurance tip speed well over 1000 per sec seems pushing full-scale metal pro peller ultra thin tip profile Its hard believe miniature pro peller its lower Reynolds Numbers wouldnt suffer severe loss efficiency have thought perhaps wrongly 900 sec about high could go thin carbon/epoxy props would like hear about com pressibility phenomena relates model props. ld pylon racers going three bladed props anticipate part #2 Hals article would like pass warning carving own props Dont depend alone template markings give anticipated blade angle looks good paper small errors creep can really screw things up Recently went through batches old props carved using markings shocked find times off original design intentions Simple angle templates made stiff paper file cards folders etc will make sure have right finally sure balance prop enough balance hori zontally t balanced vertical axis well As friend put tend four bladed prop balance phantom blades Bill Gieskieng Jr Denver CO About Interplane Struts know anyone has called attention plans Comedian July 1976 Henry Farrell #149 have process building Have run trouble plans Everything going along nicely until made interplane struts trouble developed Either cabane struts too short interplane struts too long 84 Model Aviation THE LEADER IN COMPETITION PROPELLERS SPECIAL PRO SERIES 2 FOR ROFREE FLIGHT CONTROL LINE 6 WHEELS RO WHEELS WHOLE NEW LINE OF SMOOTH INFLATABLE BIG WHEELS Smooth inflatable wheels big airplanes Features two piece bolt gether hubs hub caps Wheels can inflated deflated thru tiny valve side tire pressure de sire Truly remark able realistic looking wheel I400RI4 Diameter$795 Pair 450R4-1/2 Diameter995 Pair ISOORI 5 Diameter1195 Pair 550R5-1/2 Diameter1395 Pair 600R ameter1 595 Pair Low bounce shock absorbing wheels featuring 6 spoke dura hub finest quality hand inspected 1 75 T RWheels 1-3/4$240 Pair 200 T RWheels 2$260 Pair 225 T R 5Wheels 2-1/4$280 Pair 250 T R SWheels 2-1/2$300 Pair 275 T R 5Wheels 2-3/4$320 Pair 300 T R SWheels 3$340 Pair 325 T RWheels 3-1/4$360 Pair 350 T RWheels 3-1/2$380 Pair 2 have read article biplanes distance between top bottom wing spaced same distance apart chord wing good flying bipe thing can see wrong plans no dihedral allowed lower wing am overlooking something Charles Kolodziejsky Stone Ridge NY draftsmen designers bi planes show root rib profiles both top bottom wings display side view actual ap pearance dihedral incorporated innocently show interplane struts extending full depth gap tween wings point close aircraft center line dihedral lower wing much dihedral top wing true length terplane struts less what drawn suggestion Charles place wing panels mounted posi tion measure actual length strut its station span appreciate hearing readers about plan problems Corrections sometimes made plans during life Plan Service Wylam Plan Books of Wylams Plans Books date have able purchase book #4 am especially interested book #2 Any help can give location and/ prices books would greatly appreciated Enclosed self addressed stamped envelope Matt Jacobson 10423 112th St SW Tacoma WA 98498 Wylam Books marketed product review product review product review r H ON LY 1 LONG FILTERS IN EITHER DIRECTION CLEAN BY BACK FLUSHING Final Fitter Claimed have twice fil tering capacity available filters 1 h-in long filter works either direction cleans back flushing An extremely fine 130 micron polyester screen filters out small est particles because large filtering area does restrict fuel flow $175 Du-Bro Pro ducts Inc 480 Banner Rd Wauconda IL 60084 am trying locate copies reprints product review product review product review Model Airplane News gather Matts letter some out print Weve included Matts full address hope someone may have pleas ant news him Free Flight Champs/Mathis continued page 11 rivalry troops dont get going Tommy-T Fast Richard going have bring back ShoBiz act liven things up Since looks like USFFC stay maybe its time add some perpetual awards hope put up per tual award outdoor HLG hope others will come up similar trophies other eventsit really adds something event should state know no cases winner did earn victory outstanding performance great still have opportunity try excellent recognized final analysis having best score Class C O/T Pylon really too important universal scheme things However part idea model ing get away universal scheme thingswhich nice spend three days Taft late spring writing advatiuas mention road about thorn MA September1978 85 THEAD T SMOOTH R SLICKS 5 DUBRO PRODUCTS INCORPORATED 480 BONNER ROAD WAUcONDA ILL 60084
Edition: Model Aviation - 1978/09
Page Numbers: 6, 7, 84, 85
MIDWEST RIC Models Give choose . theres Midwest model almost kind R/C flyer de sires q5 400 South Indiana St Hobart IndIana 46342 Letters Editor letters will carefully considered general interest used Send Model Aviation 815 15th St NW Washington DC 20005 Sniffer Ive just finished reading Openers column April 1977 issue Mode Aviation read what say about Midwests Sniffer kit P 58 just couldnt believe read over again make sure wasnt seeing wrong see Ive modeling about 2 years now Super Sniffer 48 span first second model airplane decided try balsawood model walked local hobbyshop expecting buy small rubberband powered type owner asked lot questions interests financial status spare time available etc recom mended Super Sniffer Well said told easy build cheap rank beginner should have little trouble getting fly make long story little shorter built flew Cox Baby Bee what con vinced take up modeling After few extremely successful flights decided no matter what did couldnt keep drifting wind thought maybe could afford put cheap radio bring back closer field Chased darned thing 3 miles once Circle climb-circle glide-S mph wind Thats troub les started Nobody told about CG control surface area didnt have instructor pulse single channel expe rience Well first bit dust shortly thereafter knew fault Sniffers started reading some model magazines knew could make plane fly properly single-channel radio proceeded build second Super Sniffer first blue white dope tissue awfully hard see against blue sky got smart lazy results shown enclosed picture Monokote second used ORC 049 really appreciate Soft ears about 1 year old has successful flights recently sold complete outfit some local kids having lot fun thats end story have plans will soon building two Super Sniffersone free flight time dether malizer w/micro 2 ch flight pack f/f will back traditional tis sue dope intend use trans parent Monokote RC Now point letter think talking about Sniffer 37 span Super Sniffer aside size same airplane Ive tried vain find out about history model have run blank stares might able help telling get ahold Wally Sim mers someone else share some experiences model currently am flying some sailplanes am Rocky Mountain Soaring Association compete regularly Sniffer model has got much character think Ill always have around will recom mend beginner Although dont think Midwest doing justice no advertising getting difficult buy hobbyshops truly believe Sniffer enjoy able kits person can have Hey thanks shot arm ego Bill Thomas Fort Collins CO Sniffer described kitted shortly after war 049 un doubtedly smaller referred Thomas Wally Simmers S K&S Engineering 6917 W S9th St Chi cago IL 60638 interesting note good design kit sage dealers advice produced new modeler became RCer Still Props June issue published letter Mr Sidwell regarding timed speeds Formula 1 racer comment high speeds probably due error timing undoubtedly correct would have increase available power 40% go 165 187 mph mention Prather 8 X 6 prop reminded some theoretical cal culations did some months ago what size prop would best newer engines view higher rpm lower torque values maximum power output Using information available time calculations suggested 8 X 6 would best around within about 3% diameter value Prather prop can readily ex plained slight difference dynamic solidity between Prather prop 6 Model Aviation ATTACKER All-molded styrofoam airplane goes gether fast Rugged its great sport plane easy-to-fly advanced trainer Big 48 span powered 19- 35-size engines 4 chan nels Complete hardware package Designed Jim NewmanKit No 134 SUPER CHIPMUNK ARF injection-molded foam 10 19 en gines Wing span 46 Three channels En gine throttle elevator ailerons Four channels Engine throttle elevator ailerons rudder Kit No 126 STR 1K EMASTE R Wing span 55 inches Engine sizes 19 40 Foam wing cores balsa oevering material sup plied Balsa plywood fuselage die cut Balsa sheet fin stabilizer machine cut fittings hardware formed wire parts sup plied Designed Jim Newman Kit No 130 model used calculation purposes used 24000 rpm arrive ideal prop will recall Mr deBolts article May 1977 issue conditions supposed limit maximum speed about 118 mph 80% efficiency Consid ering speed lost turns true 118 mph max Formula 1 plane using Series 2 Prather prop 24000 rpm would seem noncompetitive Formula 1 other hand Vortex Theory made calculations cor rect maximum speed should 145-150 mph range 100% currently held notion efficiency modeling circles Since theory practical experience always agree would like ask would publish hopes some racers using 6 inch prop would re spond giving following information I What best race times prop 2 What ground rpm turn 3 How miles think actually travelled times reported 4 What air rpm think get answers verify calculations would glad work up article two propeller efficiency clear up propeller mystery whole thing can reduced single equation un like Mrs Watsons outverse yaw- equa tion really works engine flight speed reduction ratio etc modeler might encounter imagine J L Brownlec 2407 Quince Drive SE Decatur AL 35601 Mr Brownlees full address given facilitate correspondence important matter Perhaps someday well know about fickle fans Incidentally did spec fically state Mr Sid wells speeds result timing error Mr Brownlee does say probably Still Props Subject Hal deBolts article making Continued page 84 Fox Fuel Line Models Life Blood Passes Through Simple Piece Fuel Line Surely Want Best As engine manufacturers acutely aware large portion called engine problems reality fuel line problems Symptoms fuel line trouble going lean air leaks speed fluctuations inability get rich enough high speed restricted flow Fox Fuel Lines best materials available physical proper ties selected model use Fox Fuel Lines worlds finest Tuff Line Silicone far strongest market semi transparent shows bubbles line heat resis tant Like silicone tubing tends slip off fittings unless care taken Neoprene Actually complex compound much elastic clings fittings main disadvan tage transparent Surgical Tubing Pure Rubber Very flexible Use sharp bends necessary Semi-transparent Shows bubbles line Holds fittings well Main disadvantage tends deteriorate rapidly silicone neoprene Plastic good anybodys dont think much plastic fuel line Advantage low price transparency Disadvantage tends collapse bends hardens age heat Tends leak air fittings after ITEM FUEL LINEPRICEITEM FUEL UNEPRICE 86880 Small Neoprene2 P8g.5086885 Small Clear Pluatic2 Pkg.25 86881 Medium Neoprene2 P8g.6086886 Medium Clear Plantic2/2 P8g.30 86882 Large Neoprene2 P8g7086887 Large Clear Plastic2 P8g.40 86883 Small Tuft Line1 Pkg. 5586888 Small Surgical Tubing2 P8g.50 86884 Medium Tuft Line1 Pkg.7086889 Med Surgical Tubing2 P8g.50 86851 Large Taft Line1 P8g10086890 Large Surgical Tubing2 Pkg.60 FOX MANUFACTURING Fox Model Airplane Products 5305 Towson Smith Arkansas 72901 e 501-646-1656 Answer iWo-Channel Dilemma NIMBUS 2-channel radio system offers American engineering import prices Features include. 1 Solid state superheterodyne 2 All silicon transistor receiver circuit highly selective front end 3 RF amplifier maximum signal noise ratio unexcelled selectivity 4 2 ultra small EK SM servos greater 4 pounds output thrust 5 Receiver servos equipped 3 pin Deans gold plated plugs 6 Adjustable tension control sticks full line brochure write EK-PRODUCTS INC 3322 Stovall St Irving Texas 75061 USA Distributors dealers contact us new merchandising program 1977 EK-Prod.cts nc 779 EK-Products September 1978 7 MORE FIRST PLACE WINNERS AT THE 1977 NATIONALS THAN THE OTHER MAJOR MANUFACTURERS COMBINED IN FACT OVER THE PAST 10 YEARS MORE NAT IONALS WINNERS HAVE USED REV-UP PROPS THAN ANY OTHER BRAND Rev-Up better 1 The efficient design con stant upgrading testing program 2 B4tter quality control better selection hard maple wood 3 The best finish completely fuelproof New Improved 1978 DIAPITCHPRICE 5%34as 63489 733/4119 83 3%456 129 8A77%139 a4565A 77%139 104567149 106W SW149 10SEW159 114677% 7%7%8159 11eEW1e9 ii67189 126179 125W179 1356239 1456279 1556349 164%6449 1756599 1856599 W WIDE BLADE EW EXTRA WIDE SERIES 400 B POE SPEED NG ADVANCED DESIGN ND 1 IN PYLON RACING LEADING SPEED RECORD HOLDER OF ALL TIMES RC pv LON RACING DIAPITCHPRICE 53%4129 756149 7SN SN149 6%6% 6% 7 7%7%159 977% 7%169 CONTROL LINE SPEED& RACING DIA PITCHPRICE 4%6%7129 4%55%129 6 788%149 77%10%11169 689189 89N 9%N189 91213229 N NARROW wide formed leading edge such way cambered airfoil results Formed did say seems Midwest going manufacture kit book kit can recommended together dealer kit course contains shaped leading edge piece Midwest aware FOs sneak preview can say boys have religion Its daring imaginiative approach powered glider hotshots idea trainer must impressed revelations field testing involved very young kids Since two channels required rud der elevator flier involved four very natural stick move ments slow rate climb takes ever get ship real altitude no pressure new flier Control demands presented flier about pace molasses flow ing uphill January 11-year-old boy merely told what stick move ments launched model its first flight come down grass hadnt pushed hard enough launch second flight snagged wing tip grass cartwheeled damage third flight flew ship unaided 9minute flight Mountains words books kits magazines have shoved ginner yet problem big ever knows maybe guys have answer Letters Editor continued page 7 high performance propellers June 78 vol 4 #6 p 30 though pylon racers whatever are out province found deBolts article interesting provocative came away few misgivings think idea presented identical pitch can maintained substituting different types airfoils can very misleading can lead easily specious reasoning Determining pitch some arbitrary datum line seems largely matter choice merely lends itself fiat driving face standard pro peller section would think meaningful approach case would calculate pitch zero lift angle blade airfoil Since could much six seven degrees dif ference zero lift angles between sym metrical airfoil thick flat bottomed section would have big difference aerodynamic pitch also So does leave us would suggest setting propeller blade elements given lift coefficients design advance angles let pitch take care itself As point interest regarding use symmetrical airfoils propeller design recall NACA tests Navy pro peller speedy biconvex airfoil outer fifty percent developing standard airfoil inboard combination gave very high maximum efficiency climb acceleration poor Hal states widest part blade should near 6r station developed view planform seems put much closer hub would interested know came conclusion confuse issue mind NACA propeller compar ison test against standard propeller look ing much like Hals propeller giving highest maximum efficiency its max imum width around 38r nearly straight taper rounded tip gain 3% believe 3% gain propeller efficiency means 1% gain flight speed taken aback fact Hal turning nine inch diameter prop 27K common occurance tip speed well over 1000 per sec seems pushing full-scale metal pro peller ultra thin tip profile Its hard believe miniature pro peller its lower Reynolds Numbers wouldnt suffer severe loss efficiency have thought perhaps wrongly 900 sec about high could go thin carbon/epoxy props would like hear about com pressibility phenomena relates model props. ld pylon racers going three bladed props anticipate part #2 Hals article would like pass warning carving own props Dont depend alone template markings give anticipated blade angle looks good paper small errors creep can really screw things up Recently went through batches old props carved using markings shocked find times off original design intentions Simple angle templates made stiff paper file cards folders etc will make sure have right finally sure balance prop enough balance hori zontally t balanced vertical axis well As friend put tend four bladed prop balance phantom blades Bill Gieskieng Jr Denver CO About Interplane Struts know anyone has called attention plans Comedian July 1976 Henry Farrell #149 have process building Have run trouble plans Everything going along nicely until made interplane struts trouble developed Either cabane struts too short interplane struts too long 84 Model Aviation THE LEADER IN COMPETITION PROPELLERS SPECIAL PRO SERIES 2 FOR ROFREE FLIGHT CONTROL LINE 6 WHEELS RO WHEELS WHOLE NEW LINE OF SMOOTH INFLATABLE BIG WHEELS Smooth inflatable wheels big airplanes Features two piece bolt gether hubs hub caps Wheels can inflated deflated thru tiny valve side tire pressure de sire Truly remark able realistic looking wheel I400RI4 Diameter$795 Pair 450R4-1/2 Diameter995 Pair ISOORI 5 Diameter1195 Pair 550R5-1/2 Diameter1395 Pair 600R ameter1 595 Pair Low bounce shock absorbing wheels featuring 6 spoke dura hub finest quality hand inspected 1 75 T RWheels 1-3/4$240 Pair 200 T RWheels 2$260 Pair 225 T R 5Wheels 2-1/4$280 Pair 250 T R SWheels 2-1/2$300 Pair 275 T R 5Wheels 2-3/4$320 Pair 300 T R SWheels 3$340 Pair 325 T RWheels 3-1/4$360 Pair 350 T RWheels 3-1/2$380 Pair 2 have read article biplanes distance between top bottom wing spaced same distance apart chord wing good flying bipe thing can see wrong plans no dihedral allowed lower wing am overlooking something Charles Kolodziejsky Stone Ridge NY draftsmen designers bi planes show root rib profiles both top bottom wings display side view actual ap pearance dihedral incorporated innocently show interplane struts extending full depth gap tween wings point close aircraft center line dihedral lower wing much dihedral top wing true length terplane struts less what drawn suggestion Charles place wing panels mounted posi tion measure actual length strut its station span appreciate hearing readers about plan problems Corrections sometimes made plans during life Plan Service Wylam Plan Books of Wylams Plans Books date have able purchase book #4 am especially interested book #2 Any help can give location and/ prices books would greatly appreciated Enclosed self addressed stamped envelope Matt Jacobson 10423 112th St SW Tacoma WA 98498 Wylam Books marketed product review product review product review r H ON LY 1 LONG FILTERS IN EITHER DIRECTION CLEAN BY BACK FLUSHING Final Fitter Claimed have twice fil tering capacity available filters 1 h-in long filter works either direction cleans back flushing An extremely fine 130 micron polyester screen filters out small est particles because large filtering area does restrict fuel flow $175 Du-Bro Pro ducts Inc 480 Banner Rd Wauconda IL 60084 am trying locate copies reprints product review product review product review Model Airplane News gather Matts letter some out print Weve included Matts full address hope someone may have pleas ant news him Free Flight Champs/Mathis continued page 11 rivalry troops dont get going Tommy-T Fast Richard going have bring back ShoBiz act liven things up Since looks like USFFC stay maybe its time add some perpetual awards hope put up per tual award outdoor HLG hope others will come up similar trophies other eventsit really adds something event should state know no cases winner did earn victory outstanding performance great still have opportunity try excellent recognized final analysis having best score Class C O/T Pylon really too important universal scheme things However part idea model ing get away universal scheme thingswhich nice spend three days Taft late spring writing advatiuas mention road about thorn MA September1978 85 THEAD T SMOOTH R SLICKS 5 DUBRO PRODUCTS INCORPORATED 480 BONNER ROAD WAUcONDA ILL 60084
Edition: Model Aviation - 1978/09
Page Numbers: 6, 7, 84, 85
MIDWEST RIC Models Give choose . theres Midwest model almost kind R/C flyer de sires q5 400 South Indiana St Hobart IndIana 46342 Letters Editor letters will carefully considered general interest used Send Model Aviation 815 15th St NW Washington DC 20005 Sniffer Ive just finished reading Openers column April 1977 issue Mode Aviation read what say about Midwests Sniffer kit P 58 just couldnt believe read over again make sure wasnt seeing wrong see Ive modeling about 2 years now Super Sniffer 48 span first second model airplane decided try balsawood model walked local hobbyshop expecting buy small rubberband powered type owner asked lot questions interests financial status spare time available etc recom mended Super Sniffer Well said told easy build cheap rank beginner should have little trouble getting fly make long story little shorter built flew Cox Baby Bee what con vinced take up modeling After few extremely successful flights decided no matter what did couldnt keep drifting wind thought maybe could afford put cheap radio bring back closer field Chased darned thing 3 miles once Circle climb-circle glide-S mph wind Thats troub les started Nobody told about CG control surface area didnt have instructor pulse single channel expe rience Well first bit dust shortly thereafter knew fault Sniffers started reading some model magazines knew could make plane fly properly single-channel radio proceeded build second Super Sniffer first blue white dope tissue awfully hard see against blue sky got smart lazy results shown enclosed picture Monokote second used ORC 049 really appreciate Soft ears about 1 year old has successful flights recently sold complete outfit some local kids having lot fun thats end story have plans will soon building two Super Sniffersone free flight time dether malizer w/micro 2 ch flight pack f/f will back traditional tis sue dope intend use trans parent Monokote RC Now point letter think talking about Sniffer 37 span Super Sniffer aside size same airplane Ive tried vain find out about history model have run blank stares might able help telling get ahold Wally Sim mers someone else share some experiences model currently am flying some sailplanes am Rocky Mountain Soaring Association compete regularly Sniffer model has got much character think Ill always have around will recom mend beginner Although dont think Midwest doing justice no advertising getting difficult buy hobbyshops truly believe Sniffer enjoy able kits person can have Hey thanks shot arm ego Bill Thomas Fort Collins CO Sniffer described kitted shortly after war 049 un doubtedly smaller referred Thomas Wally Simmers S K&S Engineering 6917 W S9th St Chi cago IL 60638 interesting note good design kit sage dealers advice produced new modeler became RCer Still Props June issue published letter Mr Sidwell regarding timed speeds Formula 1 racer comment high speeds probably due error timing undoubtedly correct would have increase available power 40% go 165 187 mph mention Prather 8 X 6 prop reminded some theoretical cal culations did some months ago what size prop would best newer engines view higher rpm lower torque values maximum power output Using information available time calculations suggested 8 X 6 would best around within about 3% diameter value Prather prop can readily ex plained slight difference dynamic solidity between Prather prop 6 Model Aviation ATTACKER All-molded styrofoam airplane goes gether fast Rugged its great sport plane easy-to-fly advanced trainer Big 48 span powered 19- 35-size engines 4 chan nels Complete hardware package Designed Jim NewmanKit No 134 SUPER CHIPMUNK ARF injection-molded foam 10 19 en gines Wing span 46 Three channels En gine throttle elevator ailerons Four channels Engine throttle elevator ailerons rudder Kit No 126 STR 1K EMASTE R Wing span 55 inches Engine sizes 19 40 Foam wing cores balsa oevering material sup plied Balsa plywood fuselage die cut Balsa sheet fin stabilizer machine cut fittings hardware formed wire parts sup plied Designed Jim Newman Kit No 130 model used calculation purposes used 24000 rpm arrive ideal prop will recall Mr deBolts article May 1977 issue conditions supposed limit maximum speed about 118 mph 80% efficiency Consid ering speed lost turns true 118 mph max Formula 1 plane using Series 2 Prather prop 24000 rpm would seem noncompetitive Formula 1 other hand Vortex Theory made calculations cor rect maximum speed should 145-150 mph range 100% currently held notion efficiency modeling circles Since theory practical experience always agree would like ask would publish hopes some racers using 6 inch prop would re spond giving following information I What best race times prop 2 What ground rpm turn 3 How miles think actually travelled times reported 4 What air rpm think get answers verify calculations would glad work up article two propeller efficiency clear up propeller mystery whole thing can reduced single equation un like Mrs Watsons outverse yaw- equa tion really works engine flight speed reduction ratio etc modeler might encounter imagine J L Brownlec 2407 Quince Drive SE Decatur AL 35601 Mr Brownlees full address given facilitate correspondence important matter Perhaps someday well know about fickle fans Incidentally did spec fically state Mr Sid wells speeds result timing error Mr Brownlee does say probably Still Props Subject Hal deBolts article making Continued page 84 Fox Fuel Line Models Life Blood Passes Through Simple Piece Fuel Line Surely Want Best As engine manufacturers acutely aware large portion called engine problems reality fuel line problems Symptoms fuel line trouble going lean air leaks speed fluctuations inability get rich enough high speed restricted flow Fox Fuel Lines best materials available physical proper ties selected model use Fox Fuel Lines worlds finest Tuff Line Silicone far strongest market semi transparent shows bubbles line heat resis tant Like silicone tubing tends slip off fittings unless care taken Neoprene Actually complex compound much elastic clings fittings main disadvan tage transparent Surgical Tubing Pure Rubber Very flexible Use sharp bends necessary Semi-transparent Shows bubbles line Holds fittings well Main disadvantage tends deteriorate rapidly silicone neoprene Plastic good anybodys dont think much plastic fuel line Advantage low price transparency Disadvantage tends collapse bends hardens age heat Tends leak air fittings after ITEM FUEL LINEPRICEITEM FUEL UNEPRICE 86880 Small Neoprene2 P8g.5086885 Small Clear Pluatic2 Pkg.25 86881 Medium Neoprene2 P8g.6086886 Medium Clear Plantic2/2 P8g.30 86882 Large Neoprene2 P8g7086887 Large Clear Plastic2 P8g.40 86883 Small Tuft Line1 Pkg. 5586888 Small Surgical Tubing2 P8g.50 86884 Medium Tuft Line1 Pkg.7086889 Med Surgical Tubing2 P8g.50 86851 Large Taft Line1 P8g10086890 Large Surgical Tubing2 Pkg.60 FOX MANUFACTURING Fox Model Airplane Products 5305 Towson Smith Arkansas 72901 e 501-646-1656 Answer iWo-Channel Dilemma NIMBUS 2-channel radio system offers American engineering import prices Features include. 1 Solid state superheterodyne 2 All silicon transistor receiver circuit highly selective front end 3 RF amplifier maximum signal noise ratio unexcelled selectivity 4 2 ultra small EK SM servos greater 4 pounds output thrust 5 Receiver servos equipped 3 pin Deans gold plated plugs 6 Adjustable tension control sticks full line brochure write EK-PRODUCTS INC 3322 Stovall St Irving Texas 75061 USA Distributors dealers contact us new merchandising program 1977 EK-Prod.cts nc 779 EK-Products September 1978 7 MORE FIRST PLACE WINNERS AT THE 1977 NATIONALS THAN THE OTHER MAJOR MANUFACTURERS COMBINED IN FACT OVER THE PAST 10 YEARS MORE NAT IONALS WINNERS HAVE USED REV-UP PROPS THAN ANY OTHER BRAND Rev-Up better 1 The efficient design con stant upgrading testing program 2 B4tter quality control better selection hard maple wood 3 The best finish completely fuelproof New Improved 1978 DIAPITCHPRICE 5%34as 63489 733/4119 83 3%456 129 8A77%139 a4565A 77%139 104567149 106W SW149 10SEW159 114677% 7%7%8159 11eEW1e9 ii67189 126179 125W179 1356239 1456279 1556349 164%6449 1756599 1856599 W WIDE BLADE EW EXTRA WIDE SERIES 400 B POE SPEED NG ADVANCED DESIGN ND 1 IN PYLON RACING LEADING SPEED RECORD HOLDER OF ALL TIMES RC pv LON RACING DIAPITCHPRICE 53%4129 756149 7SN SN149 6%6% 6% 7 7%7%159 977% 7%169 CONTROL LINE SPEED& RACING DIA PITCHPRICE 4%6%7129 4%55%129 6 788%149 77%10%11169 689189 89N 9%N189 91213229 N NARROW wide formed leading edge such way cambered airfoil results Formed did say seems Midwest going manufacture kit book kit can recommended together dealer kit course contains shaped leading edge piece Midwest aware FOs sneak preview can say boys have religion Its daring imaginiative approach powered glider hotshots idea trainer must impressed revelations field testing involved very young kids Since two channels required rud der elevator flier involved four very natural stick move ments slow rate climb takes ever get ship real altitude no pressure new flier Control demands presented flier about pace molasses flow ing uphill January 11-year-old boy merely told what stick move ments launched model its first flight come down grass hadnt pushed hard enough launch second flight snagged wing tip grass cartwheeled damage third flight flew ship unaided 9minute flight Mountains words books kits magazines have shoved ginner yet problem big ever knows maybe guys have answer Letters Editor continued page 7 high performance propellers June 78 vol 4 #6 p 30 though pylon racers whatever are out province found deBolts article interesting provocative came away few misgivings think idea presented identical pitch can maintained substituting different types airfoils can very misleading can lead easily specious reasoning Determining pitch some arbitrary datum line seems largely matter choice merely lends itself fiat driving face standard pro peller section would think meaningful approach case would calculate pitch zero lift angle blade airfoil Since could much six seven degrees dif ference zero lift angles between sym metrical airfoil thick flat bottomed section would have big difference aerodynamic pitch also So does leave us would suggest setting propeller blade elements given lift coefficients design advance angles let pitch take care itself As point interest regarding use symmetrical airfoils propeller design recall NACA tests Navy pro peller speedy biconvex airfoil outer fifty percent developing standard airfoil inboard combination gave very high maximum efficiency climb acceleration poor Hal states widest part blade should near 6r station developed view planform seems put much closer hub would interested know came conclusion confuse issue mind NACA propeller compar ison test against standard propeller look ing much like Hals propeller giving highest maximum efficiency its max imum width around 38r nearly straight taper rounded tip gain 3% believe 3% gain propeller efficiency means 1% gain flight speed taken aback fact Hal turning nine inch diameter prop 27K common occurance tip speed well over 1000 per sec seems pushing full-scale metal pro peller ultra thin tip profile Its hard believe miniature pro peller its lower Reynolds Numbers wouldnt suffer severe loss efficiency have thought perhaps wrongly 900 sec about high could go thin carbon/epoxy props would like hear about com pressibility phenomena relates model props. ld pylon racers going three bladed props anticipate part #2 Hals article would like pass warning carving own props Dont depend alone template markings give anticipated blade angle looks good paper small errors creep can really screw things up Recently went through batches old props carved using markings shocked find times off original design intentions Simple angle templates made stiff paper file cards folders etc will make sure have right finally sure balance prop enough balance hori zontally t balanced vertical axis well As friend put tend four bladed prop balance phantom blades Bill Gieskieng Jr Denver CO About Interplane Struts know anyone has called attention plans Comedian July 1976 Henry Farrell #149 have process building Have run trouble plans Everything going along nicely until made interplane struts trouble developed Either cabane struts too short interplane struts too long 84 Model Aviation THE LEADER IN COMPETITION PROPELLERS SPECIAL PRO SERIES 2 FOR ROFREE FLIGHT CONTROL LINE 6 WHEELS RO WHEELS WHOLE NEW LINE OF SMOOTH INFLATABLE BIG WHEELS Smooth inflatable wheels big airplanes Features two piece bolt gether hubs hub caps Wheels can inflated deflated thru tiny valve side tire pressure de sire Truly remark able realistic looking wheel I400RI4 Diameter$795 Pair 450R4-1/2 Diameter995 Pair ISOORI 5 Diameter1195 Pair 550R5-1/2 Diameter1395 Pair 600R ameter1 595 Pair Low bounce shock absorbing wheels featuring 6 spoke dura hub finest quality hand inspected 1 75 T RWheels 1-3/4$240 Pair 200 T RWheels 2$260 Pair 225 T R 5Wheels 2-1/4$280 Pair 250 T R SWheels 2-1/2$300 Pair 275 T R 5Wheels 2-3/4$320 Pair 300 T R SWheels 3$340 Pair 325 T RWheels 3-1/4$360 Pair 350 T RWheels 3-1/2$380 Pair 2 have read article biplanes distance between top bottom wing spaced same distance apart chord wing good flying bipe thing can see wrong plans no dihedral allowed lower wing am overlooking something Charles Kolodziejsky Stone Ridge NY draftsmen designers bi planes show root rib profiles both top bottom wings display side view actual ap pearance dihedral incorporated innocently show interplane struts extending full depth gap tween wings point close aircraft center line dihedral lower wing much dihedral top wing true length terplane struts less what drawn suggestion Charles place wing panels mounted posi tion measure actual length strut its station span appreciate hearing readers about plan problems Corrections sometimes made plans during life Plan Service Wylam Plan Books of Wylams Plans Books date have able purchase book #4 am especially interested book #2 Any help can give location and/ prices books would greatly appreciated Enclosed self addressed stamped envelope Matt Jacobson 10423 112th St SW Tacoma WA 98498 Wylam Books marketed product review product review product review r H ON LY 1 LONG FILTERS IN EITHER DIRECTION CLEAN BY BACK FLUSHING Final Fitter Claimed have twice fil tering capacity available filters 1 h-in long filter works either direction cleans back flushing An extremely fine 130 micron polyester screen filters out small est particles because large filtering area does restrict fuel flow $175 Du-Bro Pro ducts Inc 480 Banner Rd Wauconda IL 60084 am trying locate copies reprints product review product review product review Model Airplane News gather Matts letter some out print Weve included Matts full address hope someone may have pleas ant news him Free Flight Champs/Mathis continued page 11 rivalry troops dont get going Tommy-T Fast Richard going have bring back ShoBiz act liven things up Since looks like USFFC stay maybe its time add some perpetual awards hope put up per tual award outdoor HLG hope others will come up similar trophies other eventsit really adds something event should state know no cases winner did earn victory outstanding performance great still have opportunity try excellent recognized final analysis having best score Class C O/T Pylon really too important universal scheme things However part idea model ing get away universal scheme thingswhich nice spend three days Taft late spring writing advatiuas mention road about thorn MA September1978 85 THEAD T SMOOTH R SLICKS 5 DUBRO PRODUCTS INCORPORATED 480 BONNER ROAD WAUcONDA ILL 60084
Edition: Model Aviation - 1978/09
Page Numbers: 6, 7, 84, 85
MIDWEST RIC Models Give choose . theres Midwest model almost kind R/C flyer de sires q5 400 South Indiana St Hobart IndIana 46342 Letters Editor letters will carefully considered general interest used Send Model Aviation 815 15th St NW Washington DC 20005 Sniffer Ive just finished reading Openers column April 1977 issue Mode Aviation read what say about Midwests Sniffer kit P 58 just couldnt believe read over again make sure wasnt seeing wrong see Ive modeling about 2 years now Super Sniffer 48 span first second model airplane decided try balsawood model walked local hobbyshop expecting buy small rubberband powered type owner asked lot questions interests financial status spare time available etc recom mended Super Sniffer Well said told easy build cheap rank beginner should have little trouble getting fly make long story little shorter built flew Cox Baby Bee what con vinced take up modeling After few extremely successful flights decided no matter what did couldnt keep drifting wind thought maybe could afford put cheap radio bring back closer field Chased darned thing 3 miles once Circle climb-circle glide-S mph wind Thats troub les started Nobody told about CG control surface area didnt have instructor pulse single channel expe rience Well first bit dust shortly thereafter knew fault Sniffers started reading some model magazines knew could make plane fly properly single-channel radio proceeded build second Super Sniffer first blue white dope tissue awfully hard see against blue sky got smart lazy results shown enclosed picture Monokote second used ORC 049 really appreciate Soft ears about 1 year old has successful flights recently sold complete outfit some local kids having lot fun thats end story have plans will soon building two Super Sniffersone free flight time dether malizer w/micro 2 ch flight pack f/f will back traditional tis sue dope intend use trans parent Monokote RC Now point letter think talking about Sniffer 37 span Super Sniffer aside size same airplane Ive tried vain find out about history model have run blank stares might able help telling get ahold Wally Sim mers someone else share some experiences model currently am flying some sailplanes am Rocky Mountain Soaring Association compete regularly Sniffer model has got much character think Ill always have around will recom mend beginner Although dont think Midwest doing justice no advertising getting difficult buy hobbyshops truly believe Sniffer enjoy able kits person can have Hey thanks shot arm ego Bill Thomas Fort Collins CO Sniffer described kitted shortly after war 049 un doubtedly smaller referred Thomas Wally Simmers S K&S Engineering 6917 W S9th St Chi cago IL 60638 interesting note good design kit sage dealers advice produced new modeler became RCer Still Props June issue published letter Mr Sidwell regarding timed speeds Formula 1 racer comment high speeds probably due error timing undoubtedly correct would have increase available power 40% go 165 187 mph mention Prather 8 X 6 prop reminded some theoretical cal culations did some months ago what size prop would best newer engines view higher rpm lower torque values maximum power output Using information available time calculations suggested 8 X 6 would best around within about 3% diameter value Prather prop can readily ex plained slight difference dynamic solidity between Prather prop 6 Model Aviation ATTACKER All-molded styrofoam airplane goes gether fast Rugged its great sport plane easy-to-fly advanced trainer Big 48 span powered 19- 35-size engines 4 chan nels Complete hardware package Designed Jim NewmanKit No 134 SUPER CHIPMUNK ARF injection-molded foam 10 19 en gines Wing span 46 Three channels En gine throttle elevator ailerons Four channels Engine throttle elevator ailerons rudder Kit No 126 STR 1K EMASTE R Wing span 55 inches Engine sizes 19 40 Foam wing cores balsa oevering material sup plied Balsa plywood fuselage die cut Balsa sheet fin stabilizer machine cut fittings hardware formed wire parts sup plied Designed Jim Newman Kit No 130 model used calculation purposes used 24000 rpm arrive ideal prop will recall Mr deBolts article May 1977 issue conditions supposed limit maximum speed about 118 mph 80% efficiency Consid ering speed lost turns true 118 mph max Formula 1 plane using Series 2 Prather prop 24000 rpm would seem noncompetitive Formula 1 other hand Vortex Theory made calculations cor rect maximum speed should 145-150 mph range 100% currently held notion efficiency modeling circles Since theory practical experience always agree would like ask would publish hopes some racers using 6 inch prop would re spond giving following information I What best race times prop 2 What ground rpm turn 3 How miles think actually travelled times reported 4 What air rpm think get answers verify calculations would glad work up article two propeller efficiency clear up propeller mystery whole thing can reduced single equation un like Mrs Watsons outverse yaw- equa tion really works engine flight speed reduction ratio etc modeler might encounter imagine J L Brownlec 2407 Quince Drive SE Decatur AL 35601 Mr Brownlees full address given facilitate correspondence important matter Perhaps someday well know about fickle fans Incidentally did spec fically state Mr Sid wells speeds result timing error Mr Brownlee does say probably Still Props Subject Hal deBolts article making Continued page 84 Fox Fuel Line Models Life Blood Passes Through Simple Piece Fuel Line Surely Want Best As engine manufacturers acutely aware large portion called engine problems reality fuel line problems Symptoms fuel line trouble going lean air leaks speed fluctuations inability get rich enough high speed restricted flow Fox Fuel Lines best materials available physical proper ties selected model use Fox Fuel Lines worlds finest Tuff Line Silicone far strongest market semi transparent shows bubbles line heat resis tant Like silicone tubing tends slip off fittings unless care taken Neoprene Actually complex compound much elastic clings fittings main disadvan tage transparent Surgical Tubing Pure Rubber Very flexible Use sharp bends necessary Semi-transparent Shows bubbles line Holds fittings well Main disadvantage tends deteriorate rapidly silicone neoprene Plastic good anybodys dont think much plastic fuel line Advantage low price transparency Disadvantage tends collapse bends hardens age heat Tends leak air fittings after ITEM FUEL LINEPRICEITEM FUEL UNEPRICE 86880 Small Neoprene2 P8g.5086885 Small Clear Pluatic2 Pkg.25 86881 Medium Neoprene2 P8g.6086886 Medium Clear Plantic2/2 P8g.30 86882 Large Neoprene2 P8g7086887 Large Clear Plastic2 P8g.40 86883 Small Tuft Line1 Pkg. 5586888 Small Surgical Tubing2 P8g.50 86884 Medium Tuft Line1 Pkg.7086889 Med Surgical Tubing2 P8g.50 86851 Large Taft Line1 P8g10086890 Large Surgical Tubing2 Pkg.60 FOX MANUFACTURING Fox Model Airplane Products 5305 Towson Smith Arkansas 72901 e 501-646-1656 Answer iWo-Channel Dilemma NIMBUS 2-channel radio system offers American engineering import prices Features include. 1 Solid state superheterodyne 2 All silicon transistor receiver circuit highly selective front end 3 RF amplifier maximum signal noise ratio unexcelled selectivity 4 2 ultra small EK SM servos greater 4 pounds output thrust 5 Receiver servos equipped 3 pin Deans gold plated plugs 6 Adjustable tension control sticks full line brochure write EK-PRODUCTS INC 3322 Stovall St Irving Texas 75061 USA Distributors dealers contact us new merchandising program 1977 EK-Prod.cts nc 779 EK-Products September 1978 7 MORE FIRST PLACE WINNERS AT THE 1977 NATIONALS THAN THE OTHER MAJOR MANUFACTURERS COMBINED IN FACT OVER THE PAST 10 YEARS MORE NAT IONALS WINNERS HAVE USED REV-UP PROPS THAN ANY OTHER BRAND Rev-Up better 1 The efficient design con stant upgrading testing program 2 B4tter quality control better selection hard maple wood 3 The best finish completely fuelproof New Improved 1978 DIAPITCHPRICE 5%34as 63489 733/4119 83 3%456 129 8A77%139 a4565A 77%139 104567149 106W SW149 10SEW159 114677% 7%7%8159 11eEW1e9 ii67189 126179 125W179 1356239 1456279 1556349 164%6449 1756599 1856599 W WIDE BLADE EW EXTRA WIDE SERIES 400 B POE SPEED NG ADVANCED DESIGN ND 1 IN PYLON RACING LEADING SPEED RECORD HOLDER OF ALL TIMES RC pv LON RACING DIAPITCHPRICE 53%4129 756149 7SN SN149 6%6% 6% 7 7%7%159 977% 7%169 CONTROL LINE SPEED& RACING DIA PITCHPRICE 4%6%7129 4%55%129 6 788%149 77%10%11169 689189 89N 9%N189 91213229 N NARROW wide formed leading edge such way cambered airfoil results Formed did say seems Midwest going manufacture kit book kit can recommended together dealer kit course contains shaped leading edge piece Midwest aware FOs sneak preview can say boys have religion Its daring imaginiative approach powered glider hotshots idea trainer must impressed revelations field testing involved very young kids Since two channels required rud der elevator flier involved four very natural stick move ments slow rate climb takes ever get ship real altitude no pressure new flier Control demands presented flier about pace molasses flow ing uphill January 11-year-old boy merely told what stick move ments launched model its first flight come down grass hadnt pushed hard enough launch second flight snagged wing tip grass cartwheeled damage third flight flew ship unaided 9minute flight Mountains words books kits magazines have shoved ginner yet problem big ever knows maybe guys have answer Letters Editor continued page 7 high performance propellers June 78 vol 4 #6 p 30 though pylon racers whatever are out province found deBolts article interesting provocative came away few misgivings think idea presented identical pitch can maintained substituting different types airfoils can very misleading can lead easily specious reasoning Determining pitch some arbitrary datum line seems largely matter choice merely lends itself fiat driving face standard pro peller section would think meaningful approach case would calculate pitch zero lift angle blade airfoil Since could much six seven degrees dif ference zero lift angles between sym metrical airfoil thick flat bottomed section would have big difference aerodynamic pitch also So does leave us would suggest setting propeller blade elements given lift coefficients design advance angles let pitch take care itself As point interest regarding use symmetrical airfoils propeller design recall NACA tests Navy pro peller speedy biconvex airfoil outer fifty percent developing standard airfoil inboard combination gave very high maximum efficiency climb acceleration poor Hal states widest part blade should near 6r station developed view planform seems put much closer hub would interested know came conclusion confuse issue mind NACA propeller compar ison test against standard propeller look ing much like Hals propeller giving highest maximum efficiency its max imum width around 38r nearly straight taper rounded tip gain 3% believe 3% gain propeller efficiency means 1% gain flight speed taken aback fact Hal turning nine inch diameter prop 27K common occurance tip speed well over 1000 per sec seems pushing full-scale metal pro peller ultra thin tip profile Its hard believe miniature pro peller its lower Reynolds Numbers wouldnt suffer severe loss efficiency have thought perhaps wrongly 900 sec about high could go thin carbon/epoxy props would like hear about com pressibility phenomena relates model props. ld pylon racers going three bladed props anticipate part #2 Hals article would like pass warning carving own props Dont depend alone template markings give anticipated blade angle looks good paper small errors creep can really screw things up Recently went through batches old props carved using markings shocked find times off original design intentions Simple angle templates made stiff paper file cards folders etc will make sure have right finally sure balance prop enough balance hori zontally t balanced vertical axis well As friend put tend four bladed prop balance phantom blades Bill Gieskieng Jr Denver CO About Interplane Struts know anyone has called attention plans Comedian July 1976 Henry Farrell #149 have process building Have run trouble plans Everything going along nicely until made interplane struts trouble developed Either cabane struts too short interplane struts too long 84 Model Aviation THE LEADER IN COMPETITION PROPELLERS SPECIAL PRO SERIES 2 FOR ROFREE FLIGHT CONTROL LINE 6 WHEELS RO WHEELS WHOLE NEW LINE OF SMOOTH INFLATABLE BIG WHEELS Smooth inflatable wheels big airplanes Features two piece bolt gether hubs hub caps Wheels can inflated deflated thru tiny valve side tire pressure de sire Truly remark able realistic looking wheel I400RI4 Diameter$795 Pair 450R4-1/2 Diameter995 Pair ISOORI 5 Diameter1195 Pair 550R5-1/2 Diameter1395 Pair 600R ameter1 595 Pair Low bounce shock absorbing wheels featuring 6 spoke dura hub finest quality hand inspected 1 75 T RWheels 1-3/4$240 Pair 200 T RWheels 2$260 Pair 225 T R 5Wheels 2-1/4$280 Pair 250 T R SWheels 2-1/2$300 Pair 275 T R 5Wheels 2-3/4$320 Pair 300 T R SWheels 3$340 Pair 325 T RWheels 3-1/4$360 Pair 350 T RWheels 3-1/2$380 Pair 2 have read article biplanes distance between top bottom wing spaced same distance apart chord wing good flying bipe thing can see wrong plans no dihedral allowed lower wing am overlooking something Charles Kolodziejsky Stone Ridge NY draftsmen designers bi planes show root rib profiles both top bottom wings display side view actual ap pearance dihedral incorporated innocently show interplane struts extending full depth gap tween wings point close aircraft center line dihedral lower wing much dihedral top wing true length terplane struts less what drawn suggestion Charles place wing panels mounted posi tion measure actual length strut its station span appreciate hearing readers about plan problems Corrections sometimes made plans during life Plan Service Wylam Plan Books of Wylams Plans Books date have able purchase book #4 am especially interested book #2 Any help can give location and/ prices books would greatly appreciated Enclosed self addressed stamped envelope Matt Jacobson 10423 112th St SW Tacoma WA 98498 Wylam Books marketed product review product review product review r H ON LY 1 LONG FILTERS IN EITHER DIRECTION CLEAN BY BACK FLUSHING Final Fitter Claimed have twice fil tering capacity available filters 1 h-in long filter works either direction cleans back flushing An extremely fine 130 micron polyester screen filters out small est particles because large filtering area does restrict fuel flow $175 Du-Bro Pro ducts Inc 480 Banner Rd Wauconda IL 60084 am trying locate copies reprints product review product review product review Model Airplane News gather Matts letter some out print Weve included Matts full address hope someone may have pleas ant news him Free Flight Champs/Mathis continued page 11 rivalry troops dont get going Tommy-T Fast Richard going have bring back ShoBiz act liven things up Since looks like USFFC stay maybe its time add some perpetual awards hope put up per tual award outdoor HLG hope others will come up similar trophies other eventsit really adds something event should state know no cases winner did earn victory outstanding performance great still have opportunity try excellent recognized final analysis having best score Class C O/T Pylon really too important universal scheme things However part idea model ing get away universal scheme thingswhich nice spend three days Taft late spring writing advatiuas mention road about thorn MA September1978 85 THEAD T SMOOTH R SLICKS 5 DUBRO PRODUCTS INCORPORATED 480 BONNER ROAD WAUcONDA ILL 60084