Control Line Aerobatics Wynn Paul THE FIVE dsked questions nov ice fliers can perplexing monotonous advanced fliers Some us hear over over some answers five often asked questions writer keeps getting can make profile run smoothly through pattern Assum ing engine mounted securely enough nose airplane doesnt vibrate too much leaves engine self tank Some fliers advance theory too solid construction can also shake plane cause problems Again assuming engine has tested block will run okay screws tight plug good spray bar-needle valve sembly tight clean have examine tank fuel line setup First lets play fuel line since easier Try different sizes fuel line bigger smaller Make certain fuel line doesnt have pin hole Try fuel filter dont have line already already have try different size hate fuel filters use some larger fuel tube Try re routing fuel line different way stead going under cylinder try around other side Reverse needle valve assembly Use some copper wire keep fuel tube getting near exhaust next thing try moving po sition fuel tank relative spray bar engine richens top loops etc try raising tank about above engine center line engine gets too lean lower tank viewed outboard side eye level engine cylinder pointing straight Make certain fuel pick ups vent tubes soldered tightly leak proof Make certain pickup tube extends within 1/16 back tank has 45-de gree bevel end youre running muffler pressure try constricting pres sure line engine running too rich maneuvers desperation move move tank middle fuse lage requires cutting rather large hole fuselage just behind engine get shiny finish Preparation wood under paint key final application clear dope another grain must filled doesnt matter whether use paper resin glue spackling clear dope Continued page 90 July1978 35 Ueltic IV created Elwood Bell has built-up 55-1/4-in wing Max 35 power own muffler Bill Simons Scorpio has 56-in CSC foam wing finished Sig paint Power Super tigre 46 first class job spite seven working days pictures Wynn Paul Unusual cooling vent airplane built uy jon Ramsden Nose shape appears distinctive too Current Sport Scale Rules sect 65a allow contestant substitute scalelike propeller regular flying prop during static judging recognizes though propeller visible flight just significant part aircrafts identity tail landing gear canopy etc 2-bladed II dia flying prop P-SI scale 4 blades model Corsair GeeBee racer 9 dia radial cowl looks ridiculously inap propriate can thus diminish appeal such subjects fact werent al lowed use scale-size colordisplay prop airplanes such would distinct disadvantage during static judging follow-up section 65b rules requires flying spinner same size shape color spinner pre sented static judging Its based premise allow change com pletely different style spinnerto facili tate using starter whatever reason would also unfair certain subject choices Normally color outlines spinner still clearly visible revolving Nobody would like see J-3 Cub flying around 2 spin ner hanging nose full scale subject didnt use type spinner cone just prop hub crankshaft lot boltsthe rules require use some sort rounded acorn prop nut safety interrelated rules provide different aircraft subjects viewed equal advantage during static flight judging problem goal inherent scale events much burden produce adequate scale prop make Sport Scale model competitive under current rules almost cases diameter flying prop will figure out several inches smaller diameter needed accurate scale prop Precision Scale usually necessary meticulous ly carve scaled-down replica out balsa wood sort time-consuming effort isnt called Sport Scale 10 feet away number blades rela tive size blades general col ors noticeable Ive found time good Sport Scale prop can made modifying stock commercial wood prop accompanying photos show some possibilities using Top Flite 12-6 Power Prop first step decide what size commercial prop best fits needs Carefully study photos and/or drawings will use presentation what judges will going Ive found props pitch 6 will usually appear too thick painted will depend primarily scale particular model Most com mercial wood props within few sizes other have essentially same width length hub area dont know actual scale length needed look prop sufficient diameter look right primar ily relation cowling ground line Sand finish off prop medium grit sandpaper Now modify ing tip shape adjusting planform blades leading trailing edges sanding block character full size propellers can cap tured Its best draw guidelines blades sand down makes easier get both blades same Dont worry about balancing since prop will never used flying running engine satisfied shape youve created taper re-round leading trailing edges sanding block sand entire prop smooth again medium grit paper Brush 4-6 coats unthinned clear dope sanding between coats fine sandpaper have built up smooth clear dope base havent sanded through wood anywhere can start painting colors Its best spray color final coats dope especially colors like silver satisfactory job can done brush remember three basic rules Thin color dope adequately al low flow smoothly 2 Always brush dry area wet area 3 Keep brush strokes minimum After colors dry spray several coats clear dope overall props shown photos painted flat black back blades scale case mounting display prop prefer epoxy extra prop nut permanently prop hub yours include spinner can hide prop nut inside yours has spinner nut Clip Wing Cub Super Chipmunk props show epoxy nut right onto front hub Thus ratty scarred flight prop spinner and/or nut removed immaculate display prop assembly simp ly spun onto engine shaft its job PLEASE DONT FLY NEAR ELEC TRIC POWER LINES Mike Gretz Box 162 Montezuma IA 50171 CL Aerobatics/Paul continued page 35 talcum powder epoxy-type paints Well does matter weight standpoint spackling auto primer fillers can heavy used too freely Silkspan Jap anese tissue over wood old stand followed several coats filler coat commercial filler talcum powder mixed clear certain apply several coats clear dope over last filler coat paint can have good base adhere durability Resin glue undercoats have come prominence last 4-5 years although article method American Modeler October 1959 finishes have proven fairly light care taken sand throughly tween applications resin glue ap plications should scraped off sur faces playing card piece 3 X 5 index card rest wiped off pa per towels Sanding between two applica tions should 300 400 paper couple coats clear applied over resin glue good base paint Spackling auto primer fillers can used care must taken sand thor oughly prevent excess build up sub sequent weight build up fellow flier 90 Model Aviation Kraftsmanship kit processed AAMCO GOLD BALSAThis Trainer will blow apart hits ground GREATEST B/C BASIC TBAINEB Design & Kit ALL TIME Ask over 25000 satisfied builders H-BAY dealers sold themSHALL WE SAY MORE Andrews Aircraft Model Co Inc US Rte 1& North St Topsijeld Mass 01981 887-8541 Sopport yoar AMA Price $3995 kit per dollar bar em alt weighed 35-size plane before after sanding auto body primer re moved three full ounces weight sand ing alone epoxy-type paints can used right bare wood up can end up some very good looking results Epoxy paints will usually go over other types dope dont bet first try ing sample Dope will adhere over epoxy-type paints According Glenn Fultz Cincinnati can spray epoxy type clear finish over kind dope finish both shiny finish fuel protection Ed Allen Southern Califor nia 500 stunt club members likes use acrylic lacquer acrylic enamel paints stunt ships Such brand names Du pont acrylic lacquer Dizler RM Nasson can used says must finish up acrylic clear enamel over paint will fuel proof Great care must exercised acrylic paints well ventilated spray area mandatory paint mask must used serious permanent injury can experienced type paints should used beginner Get some help experienced use acrylic paints After paint trim applied ink lines its time clear dope applications couple light mist coats needed seal ink lines decals letrasets edges canopy lay coats clear Some very care ful sanding wet 600 between last couple coats clear will help achieve beautiful finish rubbing compound must dope acrylic finishes plane heavy first culprit wood selection course cannot sift through find 4- 5-pound balsa However can cheat some possible build light just mediocre wood Instead using 3/32 wood substitute 1/16 Instead using hollowed block use molded balsa top bottom block See Al Meyers Mustang article March 1978 Model Aviation Instead using inch block top make fuse lage sides er use k hollowed out hollowing blocks easily should able see light 60-watt bulb through wood Regarding woodwork dont go big overhangs elevator rear plane Eliminate anything sticks out behind elevators Make tiny fillets find yourself fillet fits index finger go back sand down fit little finger After finished hollowing out everything blocks tips cowling nose inside lead ing edge etc. go back some Al Rabe once said dont go through surface least couple times blocks youre making thin enough However much glue have using cut amount half Impossible say really must force self use minimum amount glue fiberglass convince yourself will hold Remember really trying build competitive airplane needs hold together air does hit ground should total wreck words Californian Bill Fitzgerald stays together hits ground its built too heavy Sand off much possible un dercoats before painting So go down bare wood patch up Sand sand sand ready paint make first coat silverit will cover wood easily will show up flaws After first time use silver undercoat probably will never go again Sand after coat paint sparing spray gun Sand after first three coats clear finally sand rub out plane much possibleyou can cut up two ounces get consistent engine run Get back basics engine plug fuel muffler tank engine will run block another airplane youve checked loose head screws loose backplate screws clogged spray bar broken needle especially Maxes have go other components Dont hesitant change glow plugs because July1978 91 now cost dollar fuel consistent its home brew good chance could have picked up some water air Theres also chance home brew consistent last batch horrible experience cost two en gines place two Nationals some backyard brew no oil Sure lots smaller fuel distribu tors have good consistent mixes fuel need careful will maintain two gallon cans same fuel side side can run differently seems unlikely muffler could cause inconsistent run except muffler pressure too much too little Experimenting size muffler pressure lines could help some instan ces muffler pressure fitting bad place receiving too much too little pres sure Finally back pressure muf fler may causing engine heat up and/or allowing engine breathe properly good run feel inconsistent runs stem fuel tank fuel lines tank must checked leaks broken tubing clogged lines fuel tubing must go straight line possible pick up tube spray bar No bends twists necessary have removable tank makes much easier adjust tank can moved up down relation spray bar engine can adjusted shims etc recall Bill Werwage inletted mounting beams 1977 Juno could raise engine air plane viewed upright position did get design doubt seriously 25% stunt fliers could plot airfoil mathemati cally accurately scratch doubt have aeronautical design training other what picked up model magazines like sit down sketch out new plane put working drawings using proven wing areas force moment arms tailplane sizes powerplant com ponents Actually canards have seen Nationals finals Open Stunt disguised combat planes have won Walker Cup trophy Ive seen person ever fly Sea Fury Yes know twin-engine stunter placed back 60s 1967 Rich Loomis first Senior best advice can give someone wants depart kit airplane look what works other accom plished fliers well competition over period years sit down draw up couple planes appeal using some full-size plans published planes have Nation als FAI competition adapt rough drawings utilize basic impor tant ingredients must present successful stunt plane wing area related engine size total weight aspect ratio wing force moment-arms both nose tail tailplane size tail vol ume flap size thrust line placement respect wing fuselage side area con trol movement equal unequal wing pan els leading edge sweepback dihedral airfoil size tip configuration Lastly stick design three four versions work out bugs information stunt PAMPA contact Wynn Paul 1640 Maywick Drive Lex Ky. 40504 CL Racing/Lee continued page 36 units acceleration due gravity LDistance measured inches free surface fluid point pressure being measured measured direction force causing acceleration DThe density fluid measured pounds per cubic inch What formula tells us pile up more fluid top pressure feel correspondingly higher model airplane three variables 6-loading due centrifugal force plane flies circle density fuel carried tank dis tance L distance free sur face fuel hole needle valve measured perpendicular line flight Fig illustrates pressure jar water meas uring pressure water various levels jar Note pressure ex hibited independent shape container three variables G L D couple intersting numbers can calculated formula First what kind pressure change would see variable L reduced some value some other value Fig 2 graph shows pressure change water under normal force gravity function depth water much water above point water pressure being meas ured As can seen pressure changes about 0346 psi/in water about psi 10 inches order verify number built simple test apparatus consisted 104 large diameter plastic tubing pressure gauge tachment enabled read pres sures various places column Much relief theoretical values supported reality measured 36 psi bottom column 104 ches water under 1-6 acceleration re sults 36 psi OK much water jar about fuel fuel tank First off have measure G force model hence tank fuel 6 loading can calculated know line length speed plane flying few representative values 6 listed below 6 1467 x MPH2 322 X line length few representative values G listed below MPHGs 525Gs 60 10012731114 10514041228 11015401349 11516841473 12018331604 12519891740 13021511882 13523202030 14024952183 14526762242 ISO28642506 160-flat Goodyear will pulling 1611 6s Slow Rat 160 flat pulling 1409 6s Now crank 6-values first equation along density fuel 0332 lbs/cu find pressure variation 1125-mph Goodyear over /2 psi per slightly less per Slow Rat tank oneinch wide pressure variation fuel level changes full empty will neighborhood pres sure variation will occur regardless whether using pressure fuel system course Slow Rat suction systems allowed psi variation will pressure system Goodyear too its pretty obvious wider tank will result greater variation general rule keep fuel tank narrow possible Tall long OK narrow possible keep pressure change minimum good question ask much does pressure change affect total pressure pressure system order find answer have know pressure created tank using crankcase pressure set up test stand measure found tank pressure untimed crank case tap about 14 psi about 16 psi ball-check used pressure line 92 Model Aviation $ WIN $ USE DAVIS DIESEL CONVERTER AT THE 1978 NATS Fastest Time CL$10000 Highest Time FF$10000 Highest Points /zA Stunt$10000 Davis Diesel Devlopment Inc Box 141 DEPT E MILFORD CT 06460 LiPHONE 203 877-1670
Edition: Model Aviation - 1978/07
Page Numbers: 35, 90, 91, 92
Control Line Aerobatics Wynn Paul THE FIVE dsked questions nov ice fliers can perplexing monotonous advanced fliers Some us hear over over some answers five often asked questions writer keeps getting can make profile run smoothly through pattern Assum ing engine mounted securely enough nose airplane doesnt vibrate too much leaves engine self tank Some fliers advance theory too solid construction can also shake plane cause problems Again assuming engine has tested block will run okay screws tight plug good spray bar-needle valve sembly tight clean have examine tank fuel line setup First lets play fuel line since easier Try different sizes fuel line bigger smaller Make certain fuel line doesnt have pin hole Try fuel filter dont have line already already have try different size hate fuel filters use some larger fuel tube Try re routing fuel line different way stead going under cylinder try around other side Reverse needle valve assembly Use some copper wire keep fuel tube getting near exhaust next thing try moving po sition fuel tank relative spray bar engine richens top loops etc try raising tank about above engine center line engine gets too lean lower tank viewed outboard side eye level engine cylinder pointing straight Make certain fuel pick ups vent tubes soldered tightly leak proof Make certain pickup tube extends within 1/16 back tank has 45-de gree bevel end youre running muffler pressure try constricting pres sure line engine running too rich maneuvers desperation move move tank middle fuse lage requires cutting rather large hole fuselage just behind engine get shiny finish Preparation wood under paint key final application clear dope another grain must filled doesnt matter whether use paper resin glue spackling clear dope Continued page 90 July1978 35 Ueltic IV created Elwood Bell has built-up 55-1/4-in wing Max 35 power own muffler Bill Simons Scorpio has 56-in CSC foam wing finished Sig paint Power Super tigre 46 first class job spite seven working days pictures Wynn Paul Unusual cooling vent airplane built uy jon Ramsden Nose shape appears distinctive too Current Sport Scale Rules sect 65a allow contestant substitute scalelike propeller regular flying prop during static judging recognizes though propeller visible flight just significant part aircrafts identity tail landing gear canopy etc 2-bladed II dia flying prop P-SI scale 4 blades model Corsair GeeBee racer 9 dia radial cowl looks ridiculously inap propriate can thus diminish appeal such subjects fact werent al lowed use scale-size colordisplay prop airplanes such would distinct disadvantage during static judging follow-up section 65b rules requires flying spinner same size shape color spinner pre sented static judging Its based premise allow change com pletely different style spinnerto facili tate using starter whatever reason would also unfair certain subject choices Normally color outlines spinner still clearly visible revolving Nobody would like see J-3 Cub flying around 2 spin ner hanging nose full scale subject didnt use type spinner cone just prop hub crankshaft lot boltsthe rules require use some sort rounded acorn prop nut safety interrelated rules provide different aircraft subjects viewed equal advantage during static flight judging problem goal inherent scale events much burden produce adequate scale prop make Sport Scale model competitive under current rules almost cases diameter flying prop will figure out several inches smaller diameter needed accurate scale prop Precision Scale usually necessary meticulous ly carve scaled-down replica out balsa wood sort time-consuming effort isnt called Sport Scale 10 feet away number blades rela tive size blades general col ors noticeable Ive found time good Sport Scale prop can made modifying stock commercial wood prop accompanying photos show some possibilities using Top Flite 12-6 Power Prop first step decide what size commercial prop best fits needs Carefully study photos and/or drawings will use presentation what judges will going Ive found props pitch 6 will usually appear too thick painted will depend primarily scale particular model Most com mercial wood props within few sizes other have essentially same width length hub area dont know actual scale length needed look prop sufficient diameter look right primar ily relation cowling ground line Sand finish off prop medium grit sandpaper Now modify ing tip shape adjusting planform blades leading trailing edges sanding block character full size propellers can cap tured Its best draw guidelines blades sand down makes easier get both blades same Dont worry about balancing since prop will never used flying running engine satisfied shape youve created taper re-round leading trailing edges sanding block sand entire prop smooth again medium grit paper Brush 4-6 coats unthinned clear dope sanding between coats fine sandpaper have built up smooth clear dope base havent sanded through wood anywhere can start painting colors Its best spray color final coats dope especially colors like silver satisfactory job can done brush remember three basic rules Thin color dope adequately al low flow smoothly 2 Always brush dry area wet area 3 Keep brush strokes minimum After colors dry spray several coats clear dope overall props shown photos painted flat black back blades scale case mounting display prop prefer epoxy extra prop nut permanently prop hub yours include spinner can hide prop nut inside yours has spinner nut Clip Wing Cub Super Chipmunk props show epoxy nut right onto front hub Thus ratty scarred flight prop spinner and/or nut removed immaculate display prop assembly simp ly spun onto engine shaft its job PLEASE DONT FLY NEAR ELEC TRIC POWER LINES Mike Gretz Box 162 Montezuma IA 50171 CL Aerobatics/Paul continued page 35 talcum powder epoxy-type paints Well does matter weight standpoint spackling auto primer fillers can heavy used too freely Silkspan Jap anese tissue over wood old stand followed several coats filler coat commercial filler talcum powder mixed clear certain apply several coats clear dope over last filler coat paint can have good base adhere durability Resin glue undercoats have come prominence last 4-5 years although article method American Modeler October 1959 finishes have proven fairly light care taken sand throughly tween applications resin glue ap plications should scraped off sur faces playing card piece 3 X 5 index card rest wiped off pa per towels Sanding between two applica tions should 300 400 paper couple coats clear applied over resin glue good base paint Spackling auto primer fillers can used care must taken sand thor oughly prevent excess build up sub sequent weight build up fellow flier 90 Model Aviation Kraftsmanship kit processed AAMCO GOLD BALSAThis Trainer will blow apart hits ground GREATEST B/C BASIC TBAINEB Design & Kit ALL TIME Ask over 25000 satisfied builders H-BAY dealers sold themSHALL WE SAY MORE Andrews Aircraft Model Co Inc US Rte 1& North St Topsijeld Mass 01981 887-8541 Sopport yoar AMA Price $3995 kit per dollar bar em alt weighed 35-size plane before after sanding auto body primer re moved three full ounces weight sand ing alone epoxy-type paints can used right bare wood up can end up some very good looking results Epoxy paints will usually go over other types dope dont bet first try ing sample Dope will adhere over epoxy-type paints According Glenn Fultz Cincinnati can spray epoxy type clear finish over kind dope finish both shiny finish fuel protection Ed Allen Southern Califor nia 500 stunt club members likes use acrylic lacquer acrylic enamel paints stunt ships Such brand names Du pont acrylic lacquer Dizler RM Nasson can used says must finish up acrylic clear enamel over paint will fuel proof Great care must exercised acrylic paints well ventilated spray area mandatory paint mask must used serious permanent injury can experienced type paints should used beginner Get some help experienced use acrylic paints After paint trim applied ink lines its time clear dope applications couple light mist coats needed seal ink lines decals letrasets edges canopy lay coats clear Some very care ful sanding wet 600 between last couple coats clear will help achieve beautiful finish rubbing compound must dope acrylic finishes plane heavy first culprit wood selection course cannot sift through find 4- 5-pound balsa However can cheat some possible build light just mediocre wood Instead using 3/32 wood substitute 1/16 Instead using hollowed block use molded balsa top bottom block See Al Meyers Mustang article March 1978 Model Aviation Instead using inch block top make fuse lage sides er use k hollowed out hollowing blocks easily should able see light 60-watt bulb through wood Regarding woodwork dont go big overhangs elevator rear plane Eliminate anything sticks out behind elevators Make tiny fillets find yourself fillet fits index finger go back sand down fit little finger After finished hollowing out everything blocks tips cowling nose inside lead ing edge etc. go back some Al Rabe once said dont go through surface least couple times blocks youre making thin enough However much glue have using cut amount half Impossible say really must force self use minimum amount glue fiberglass convince yourself will hold Remember really trying build competitive airplane needs hold together air does hit ground should total wreck words Californian Bill Fitzgerald stays together hits ground its built too heavy Sand off much possible un dercoats before painting So go down bare wood patch up Sand sand sand ready paint make first coat silverit will cover wood easily will show up flaws After first time use silver undercoat probably will never go again Sand after coat paint sparing spray gun Sand after first three coats clear finally sand rub out plane much possibleyou can cut up two ounces get consistent engine run Get back basics engine plug fuel muffler tank engine will run block another airplane youve checked loose head screws loose backplate screws clogged spray bar broken needle especially Maxes have go other components Dont hesitant change glow plugs because July1978 91 now cost dollar fuel consistent its home brew good chance could have picked up some water air Theres also chance home brew consistent last batch horrible experience cost two en gines place two Nationals some backyard brew no oil Sure lots smaller fuel distribu tors have good consistent mixes fuel need careful will maintain two gallon cans same fuel side side can run differently seems unlikely muffler could cause inconsistent run except muffler pressure too much too little Experimenting size muffler pressure lines could help some instan ces muffler pressure fitting bad place receiving too much too little pres sure Finally back pressure muf fler may causing engine heat up and/or allowing engine breathe properly good run feel inconsistent runs stem fuel tank fuel lines tank must checked leaks broken tubing clogged lines fuel tubing must go straight line possible pick up tube spray bar No bends twists necessary have removable tank makes much easier adjust tank can moved up down relation spray bar engine can adjusted shims etc recall Bill Werwage inletted mounting beams 1977 Juno could raise engine air plane viewed upright position did get design doubt seriously 25% stunt fliers could plot airfoil mathemati cally accurately scratch doubt have aeronautical design training other what picked up model magazines like sit down sketch out new plane put working drawings using proven wing areas force moment arms tailplane sizes powerplant com ponents Actually canards have seen Nationals finals Open Stunt disguised combat planes have won Walker Cup trophy Ive seen person ever fly Sea Fury Yes know twin-engine stunter placed back 60s 1967 Rich Loomis first Senior best advice can give someone wants depart kit airplane look what works other accom plished fliers well competition over period years sit down draw up couple planes appeal using some full-size plans published planes have Nation als FAI competition adapt rough drawings utilize basic impor tant ingredients must present successful stunt plane wing area related engine size total weight aspect ratio wing force moment-arms both nose tail tailplane size tail vol ume flap size thrust line placement respect wing fuselage side area con trol movement equal unequal wing pan els leading edge sweepback dihedral airfoil size tip configuration Lastly stick design three four versions work out bugs information stunt PAMPA contact Wynn Paul 1640 Maywick Drive Lex Ky. 40504 CL Racing/Lee continued page 36 units acceleration due gravity LDistance measured inches free surface fluid point pressure being measured measured direction force causing acceleration DThe density fluid measured pounds per cubic inch What formula tells us pile up more fluid top pressure feel correspondingly higher model airplane three variables 6-loading due centrifugal force plane flies circle density fuel carried tank dis tance L distance free sur face fuel hole needle valve measured perpendicular line flight Fig illustrates pressure jar water meas uring pressure water various levels jar Note pressure ex hibited independent shape container three variables G L D couple intersting numbers can calculated formula First what kind pressure change would see variable L reduced some value some other value Fig 2 graph shows pressure change water under normal force gravity function depth water much water above point water pressure being meas ured As can seen pressure changes about 0346 psi/in water about psi 10 inches order verify number built simple test apparatus consisted 104 large diameter plastic tubing pressure gauge tachment enabled read pres sures various places column Much relief theoretical values supported reality measured 36 psi bottom column 104 ches water under 1-6 acceleration re sults 36 psi OK much water jar about fuel fuel tank First off have measure G force model hence tank fuel 6 loading can calculated know line length speed plane flying few representative values 6 listed below 6 1467 x MPH2 322 X line length few representative values G listed below MPHGs 525Gs 60 10012731114 10514041228 11015401349 11516841473 12018331604 12519891740 13021511882 13523202030 14024952183 14526762242 ISO28642506 160-flat Goodyear will pulling 1611 6s Slow Rat 160 flat pulling 1409 6s Now crank 6-values first equation along density fuel 0332 lbs/cu find pressure variation 1125-mph Goodyear over /2 psi per slightly less per Slow Rat tank oneinch wide pressure variation fuel level changes full empty will neighborhood pres sure variation will occur regardless whether using pressure fuel system course Slow Rat suction systems allowed psi variation will pressure system Goodyear too its pretty obvious wider tank will result greater variation general rule keep fuel tank narrow possible Tall long OK narrow possible keep pressure change minimum good question ask much does pressure change affect total pressure pressure system order find answer have know pressure created tank using crankcase pressure set up test stand measure found tank pressure untimed crank case tap about 14 psi about 16 psi ball-check used pressure line 92 Model Aviation $ WIN $ USE DAVIS DIESEL CONVERTER AT THE 1978 NATS Fastest Time CL$10000 Highest Time FF$10000 Highest Points /zA Stunt$10000 Davis Diesel Devlopment Inc Box 141 DEPT E MILFORD CT 06460 LiPHONE 203 877-1670
Edition: Model Aviation - 1978/07
Page Numbers: 35, 90, 91, 92
Control Line Aerobatics Wynn Paul THE FIVE dsked questions nov ice fliers can perplexing monotonous advanced fliers Some us hear over over some answers five often asked questions writer keeps getting can make profile run smoothly through pattern Assum ing engine mounted securely enough nose airplane doesnt vibrate too much leaves engine self tank Some fliers advance theory too solid construction can also shake plane cause problems Again assuming engine has tested block will run okay screws tight plug good spray bar-needle valve sembly tight clean have examine tank fuel line setup First lets play fuel line since easier Try different sizes fuel line bigger smaller Make certain fuel line doesnt have pin hole Try fuel filter dont have line already already have try different size hate fuel filters use some larger fuel tube Try re routing fuel line different way stead going under cylinder try around other side Reverse needle valve assembly Use some copper wire keep fuel tube getting near exhaust next thing try moving po sition fuel tank relative spray bar engine richens top loops etc try raising tank about above engine center line engine gets too lean lower tank viewed outboard side eye level engine cylinder pointing straight Make certain fuel pick ups vent tubes soldered tightly leak proof Make certain pickup tube extends within 1/16 back tank has 45-de gree bevel end youre running muffler pressure try constricting pres sure line engine running too rich maneuvers desperation move move tank middle fuse lage requires cutting rather large hole fuselage just behind engine get shiny finish Preparation wood under paint key final application clear dope another grain must filled doesnt matter whether use paper resin glue spackling clear dope Continued page 90 July1978 35 Ueltic IV created Elwood Bell has built-up 55-1/4-in wing Max 35 power own muffler Bill Simons Scorpio has 56-in CSC foam wing finished Sig paint Power Super tigre 46 first class job spite seven working days pictures Wynn Paul Unusual cooling vent airplane built uy jon Ramsden Nose shape appears distinctive too Current Sport Scale Rules sect 65a allow contestant substitute scalelike propeller regular flying prop during static judging recognizes though propeller visible flight just significant part aircrafts identity tail landing gear canopy etc 2-bladed II dia flying prop P-SI scale 4 blades model Corsair GeeBee racer 9 dia radial cowl looks ridiculously inap propriate can thus diminish appeal such subjects fact werent al lowed use scale-size colordisplay prop airplanes such would distinct disadvantage during static judging follow-up section 65b rules requires flying spinner same size shape color spinner pre sented static judging Its based premise allow change com pletely different style spinnerto facili tate using starter whatever reason would also unfair certain subject choices Normally color outlines spinner still clearly visible revolving Nobody would like see J-3 Cub flying around 2 spin ner hanging nose full scale subject didnt use type spinner cone just prop hub crankshaft lot boltsthe rules require use some sort rounded acorn prop nut safety interrelated rules provide different aircraft subjects viewed equal advantage during static flight judging problem goal inherent scale events much burden produce adequate scale prop make Sport Scale model competitive under current rules almost cases diameter flying prop will figure out several inches smaller diameter needed accurate scale prop Precision Scale usually necessary meticulous ly carve scaled-down replica out balsa wood sort time-consuming effort isnt called Sport Scale 10 feet away number blades rela tive size blades general col ors noticeable Ive found time good Sport Scale prop can made modifying stock commercial wood prop accompanying photos show some possibilities using Top Flite 12-6 Power Prop first step decide what size commercial prop best fits needs Carefully study photos and/or drawings will use presentation what judges will going Ive found props pitch 6 will usually appear too thick painted will depend primarily scale particular model Most com mercial wood props within few sizes other have essentially same width length hub area dont know actual scale length needed look prop sufficient diameter look right primar ily relation cowling ground line Sand finish off prop medium grit sandpaper Now modify ing tip shape adjusting planform blades leading trailing edges sanding block character full size propellers can cap tured Its best draw guidelines blades sand down makes easier get both blades same Dont worry about balancing since prop will never used flying running engine satisfied shape youve created taper re-round leading trailing edges sanding block sand entire prop smooth again medium grit paper Brush 4-6 coats unthinned clear dope sanding between coats fine sandpaper have built up smooth clear dope base havent sanded through wood anywhere can start painting colors Its best spray color final coats dope especially colors like silver satisfactory job can done brush remember three basic rules Thin color dope adequately al low flow smoothly 2 Always brush dry area wet area 3 Keep brush strokes minimum After colors dry spray several coats clear dope overall props shown photos painted flat black back blades scale case mounting display prop prefer epoxy extra prop nut permanently prop hub yours include spinner can hide prop nut inside yours has spinner nut Clip Wing Cub Super Chipmunk props show epoxy nut right onto front hub Thus ratty scarred flight prop spinner and/or nut removed immaculate display prop assembly simp ly spun onto engine shaft its job PLEASE DONT FLY NEAR ELEC TRIC POWER LINES Mike Gretz Box 162 Montezuma IA 50171 CL Aerobatics/Paul continued page 35 talcum powder epoxy-type paints Well does matter weight standpoint spackling auto primer fillers can heavy used too freely Silkspan Jap anese tissue over wood old stand followed several coats filler coat commercial filler talcum powder mixed clear certain apply several coats clear dope over last filler coat paint can have good base adhere durability Resin glue undercoats have come prominence last 4-5 years although article method American Modeler October 1959 finishes have proven fairly light care taken sand throughly tween applications resin glue ap plications should scraped off sur faces playing card piece 3 X 5 index card rest wiped off pa per towels Sanding between two applica tions should 300 400 paper couple coats clear applied over resin glue good base paint Spackling auto primer fillers can used care must taken sand thor oughly prevent excess build up sub sequent weight build up fellow flier 90 Model Aviation Kraftsmanship kit processed AAMCO GOLD BALSAThis Trainer will blow apart hits ground GREATEST B/C BASIC TBAINEB Design & Kit ALL TIME Ask over 25000 satisfied builders H-BAY dealers sold themSHALL WE SAY MORE Andrews Aircraft Model Co Inc US Rte 1& North St Topsijeld Mass 01981 887-8541 Sopport yoar AMA Price $3995 kit per dollar bar em alt weighed 35-size plane before after sanding auto body primer re moved three full ounces weight sand ing alone epoxy-type paints can used right bare wood up can end up some very good looking results Epoxy paints will usually go over other types dope dont bet first try ing sample Dope will adhere over epoxy-type paints According Glenn Fultz Cincinnati can spray epoxy type clear finish over kind dope finish both shiny finish fuel protection Ed Allen Southern Califor nia 500 stunt club members likes use acrylic lacquer acrylic enamel paints stunt ships Such brand names Du pont acrylic lacquer Dizler RM Nasson can used says must finish up acrylic clear enamel over paint will fuel proof Great care must exercised acrylic paints well ventilated spray area mandatory paint mask must used serious permanent injury can experienced type paints should used beginner Get some help experienced use acrylic paints After paint trim applied ink lines its time clear dope applications couple light mist coats needed seal ink lines decals letrasets edges canopy lay coats clear Some very care ful sanding wet 600 between last couple coats clear will help achieve beautiful finish rubbing compound must dope acrylic finishes plane heavy first culprit wood selection course cannot sift through find 4- 5-pound balsa However can cheat some possible build light just mediocre wood Instead using 3/32 wood substitute 1/16 Instead using hollowed block use molded balsa top bottom block See Al Meyers Mustang article March 1978 Model Aviation Instead using inch block top make fuse lage sides er use k hollowed out hollowing blocks easily should able see light 60-watt bulb through wood Regarding woodwork dont go big overhangs elevator rear plane Eliminate anything sticks out behind elevators Make tiny fillets find yourself fillet fits index finger go back sand down fit little finger After finished hollowing out everything blocks tips cowling nose inside lead ing edge etc. go back some Al Rabe once said dont go through surface least couple times blocks youre making thin enough However much glue have using cut amount half Impossible say really must force self use minimum amount glue fiberglass convince yourself will hold Remember really trying build competitive airplane needs hold together air does hit ground should total wreck words Californian Bill Fitzgerald stays together hits ground its built too heavy Sand off much possible un dercoats before painting So go down bare wood patch up Sand sand sand ready paint make first coat silverit will cover wood easily will show up flaws After first time use silver undercoat probably will never go again Sand after coat paint sparing spray gun Sand after first three coats clear finally sand rub out plane much possibleyou can cut up two ounces get consistent engine run Get back basics engine plug fuel muffler tank engine will run block another airplane youve checked loose head screws loose backplate screws clogged spray bar broken needle especially Maxes have go other components Dont hesitant change glow plugs because July1978 91 now cost dollar fuel consistent its home brew good chance could have picked up some water air Theres also chance home brew consistent last batch horrible experience cost two en gines place two Nationals some backyard brew no oil Sure lots smaller fuel distribu tors have good consistent mixes fuel need careful will maintain two gallon cans same fuel side side can run differently seems unlikely muffler could cause inconsistent run except muffler pressure too much too little Experimenting size muffler pressure lines could help some instan ces muffler pressure fitting bad place receiving too much too little pres sure Finally back pressure muf fler may causing engine heat up and/or allowing engine breathe properly good run feel inconsistent runs stem fuel tank fuel lines tank must checked leaks broken tubing clogged lines fuel tubing must go straight line possible pick up tube spray bar No bends twists necessary have removable tank makes much easier adjust tank can moved up down relation spray bar engine can adjusted shims etc recall Bill Werwage inletted mounting beams 1977 Juno could raise engine air plane viewed upright position did get design doubt seriously 25% stunt fliers could plot airfoil mathemati cally accurately scratch doubt have aeronautical design training other what picked up model magazines like sit down sketch out new plane put working drawings using proven wing areas force moment arms tailplane sizes powerplant com ponents Actually canards have seen Nationals finals Open Stunt disguised combat planes have won Walker Cup trophy Ive seen person ever fly Sea Fury Yes know twin-engine stunter placed back 60s 1967 Rich Loomis first Senior best advice can give someone wants depart kit airplane look what works other accom plished fliers well competition over period years sit down draw up couple planes appeal using some full-size plans published planes have Nation als FAI competition adapt rough drawings utilize basic impor tant ingredients must present successful stunt plane wing area related engine size total weight aspect ratio wing force moment-arms both nose tail tailplane size tail vol ume flap size thrust line placement respect wing fuselage side area con trol movement equal unequal wing pan els leading edge sweepback dihedral airfoil size tip configuration Lastly stick design three four versions work out bugs information stunt PAMPA contact Wynn Paul 1640 Maywick Drive Lex Ky. 40504 CL Racing/Lee continued page 36 units acceleration due gravity LDistance measured inches free surface fluid point pressure being measured measured direction force causing acceleration DThe density fluid measured pounds per cubic inch What formula tells us pile up more fluid top pressure feel correspondingly higher model airplane three variables 6-loading due centrifugal force plane flies circle density fuel carried tank dis tance L distance free sur face fuel hole needle valve measured perpendicular line flight Fig illustrates pressure jar water meas uring pressure water various levels jar Note pressure ex hibited independent shape container three variables G L D couple intersting numbers can calculated formula First what kind pressure change would see variable L reduced some value some other value Fig 2 graph shows pressure change water under normal force gravity function depth water much water above point water pressure being meas ured As can seen pressure changes about 0346 psi/in water about psi 10 inches order verify number built simple test apparatus consisted 104 large diameter plastic tubing pressure gauge tachment enabled read pres sures various places column Much relief theoretical values supported reality measured 36 psi bottom column 104 ches water under 1-6 acceleration re sults 36 psi OK much water jar about fuel fuel tank First off have measure G force model hence tank fuel 6 loading can calculated know line length speed plane flying few representative values 6 listed below 6 1467 x MPH2 322 X line length few representative values G listed below MPHGs 525Gs 60 10012731114 10514041228 11015401349 11516841473 12018331604 12519891740 13021511882 13523202030 14024952183 14526762242 ISO28642506 160-flat Goodyear will pulling 1611 6s Slow Rat 160 flat pulling 1409 6s Now crank 6-values first equation along density fuel 0332 lbs/cu find pressure variation 1125-mph Goodyear over /2 psi per slightly less per Slow Rat tank oneinch wide pressure variation fuel level changes full empty will neighborhood pres sure variation will occur regardless whether using pressure fuel system course Slow Rat suction systems allowed psi variation will pressure system Goodyear too its pretty obvious wider tank will result greater variation general rule keep fuel tank narrow possible Tall long OK narrow possible keep pressure change minimum good question ask much does pressure change affect total pressure pressure system order find answer have know pressure created tank using crankcase pressure set up test stand measure found tank pressure untimed crank case tap about 14 psi about 16 psi ball-check used pressure line 92 Model Aviation $ WIN $ USE DAVIS DIESEL CONVERTER AT THE 1978 NATS Fastest Time CL$10000 Highest Time FF$10000 Highest Points /zA Stunt$10000 Davis Diesel Devlopment Inc Box 141 DEPT E MILFORD CT 06460 LiPHONE 203 877-1670
Edition: Model Aviation - 1978/07
Page Numbers: 35, 90, 91, 92
Control Line Aerobatics Wynn Paul THE FIVE dsked questions nov ice fliers can perplexing monotonous advanced fliers Some us hear over over some answers five often asked questions writer keeps getting can make profile run smoothly through pattern Assum ing engine mounted securely enough nose airplane doesnt vibrate too much leaves engine self tank Some fliers advance theory too solid construction can also shake plane cause problems Again assuming engine has tested block will run okay screws tight plug good spray bar-needle valve sembly tight clean have examine tank fuel line setup First lets play fuel line since easier Try different sizes fuel line bigger smaller Make certain fuel line doesnt have pin hole Try fuel filter dont have line already already have try different size hate fuel filters use some larger fuel tube Try re routing fuel line different way stead going under cylinder try around other side Reverse needle valve assembly Use some copper wire keep fuel tube getting near exhaust next thing try moving po sition fuel tank relative spray bar engine richens top loops etc try raising tank about above engine center line engine gets too lean lower tank viewed outboard side eye level engine cylinder pointing straight Make certain fuel pick ups vent tubes soldered tightly leak proof Make certain pickup tube extends within 1/16 back tank has 45-de gree bevel end youre running muffler pressure try constricting pres sure line engine running too rich maneuvers desperation move move tank middle fuse lage requires cutting rather large hole fuselage just behind engine get shiny finish Preparation wood under paint key final application clear dope another grain must filled doesnt matter whether use paper resin glue spackling clear dope Continued page 90 July1978 35 Ueltic IV created Elwood Bell has built-up 55-1/4-in wing Max 35 power own muffler Bill Simons Scorpio has 56-in CSC foam wing finished Sig paint Power Super tigre 46 first class job spite seven working days pictures Wynn Paul Unusual cooling vent airplane built uy jon Ramsden Nose shape appears distinctive too Current Sport Scale Rules sect 65a allow contestant substitute scalelike propeller regular flying prop during static judging recognizes though propeller visible flight just significant part aircrafts identity tail landing gear canopy etc 2-bladed II dia flying prop P-SI scale 4 blades model Corsair GeeBee racer 9 dia radial cowl looks ridiculously inap propriate can thus diminish appeal such subjects fact werent al lowed use scale-size colordisplay prop airplanes such would distinct disadvantage during static judging follow-up section 65b rules requires flying spinner same size shape color spinner pre sented static judging Its based premise allow change com pletely different style spinnerto facili tate using starter whatever reason would also unfair certain subject choices Normally color outlines spinner still clearly visible revolving Nobody would like see J-3 Cub flying around 2 spin ner hanging nose full scale subject didnt use type spinner cone just prop hub crankshaft lot boltsthe rules require use some sort rounded acorn prop nut safety interrelated rules provide different aircraft subjects viewed equal advantage during static flight judging problem goal inherent scale events much burden produce adequate scale prop make Sport Scale model competitive under current rules almost cases diameter flying prop will figure out several inches smaller diameter needed accurate scale prop Precision Scale usually necessary meticulous ly carve scaled-down replica out balsa wood sort time-consuming effort isnt called Sport Scale 10 feet away number blades rela tive size blades general col ors noticeable Ive found time good Sport Scale prop can made modifying stock commercial wood prop accompanying photos show some possibilities using Top Flite 12-6 Power Prop first step decide what size commercial prop best fits needs Carefully study photos and/or drawings will use presentation what judges will going Ive found props pitch 6 will usually appear too thick painted will depend primarily scale particular model Most com mercial wood props within few sizes other have essentially same width length hub area dont know actual scale length needed look prop sufficient diameter look right primar ily relation cowling ground line Sand finish off prop medium grit sandpaper Now modify ing tip shape adjusting planform blades leading trailing edges sanding block character full size propellers can cap tured Its best draw guidelines blades sand down makes easier get both blades same Dont worry about balancing since prop will never used flying running engine satisfied shape youve created taper re-round leading trailing edges sanding block sand entire prop smooth again medium grit paper Brush 4-6 coats unthinned clear dope sanding between coats fine sandpaper have built up smooth clear dope base havent sanded through wood anywhere can start painting colors Its best spray color final coats dope especially colors like silver satisfactory job can done brush remember three basic rules Thin color dope adequately al low flow smoothly 2 Always brush dry area wet area 3 Keep brush strokes minimum After colors dry spray several coats clear dope overall props shown photos painted flat black back blades scale case mounting display prop prefer epoxy extra prop nut permanently prop hub yours include spinner can hide prop nut inside yours has spinner nut Clip Wing Cub Super Chipmunk props show epoxy nut right onto front hub Thus ratty scarred flight prop spinner and/or nut removed immaculate display prop assembly simp ly spun onto engine shaft its job PLEASE DONT FLY NEAR ELEC TRIC POWER LINES Mike Gretz Box 162 Montezuma IA 50171 CL Aerobatics/Paul continued page 35 talcum powder epoxy-type paints Well does matter weight standpoint spackling auto primer fillers can heavy used too freely Silkspan Jap anese tissue over wood old stand followed several coats filler coat commercial filler talcum powder mixed clear certain apply several coats clear dope over last filler coat paint can have good base adhere durability Resin glue undercoats have come prominence last 4-5 years although article method American Modeler October 1959 finishes have proven fairly light care taken sand throughly tween applications resin glue ap plications should scraped off sur faces playing card piece 3 X 5 index card rest wiped off pa per towels Sanding between two applica tions should 300 400 paper couple coats clear applied over resin glue good base paint Spackling auto primer fillers can used care must taken sand thor oughly prevent excess build up sub sequent weight build up fellow flier 90 Model Aviation Kraftsmanship kit processed AAMCO GOLD BALSAThis Trainer will blow apart hits ground GREATEST B/C BASIC TBAINEB Design & Kit ALL TIME Ask over 25000 satisfied builders H-BAY dealers sold themSHALL WE SAY MORE Andrews Aircraft Model Co Inc US Rte 1& North St Topsijeld Mass 01981 887-8541 Sopport yoar AMA Price $3995 kit per dollar bar em alt weighed 35-size plane before after sanding auto body primer re moved three full ounces weight sand ing alone epoxy-type paints can used right bare wood up can end up some very good looking results Epoxy paints will usually go over other types dope dont bet first try ing sample Dope will adhere over epoxy-type paints According Glenn Fultz Cincinnati can spray epoxy type clear finish over kind dope finish both shiny finish fuel protection Ed Allen Southern Califor nia 500 stunt club members likes use acrylic lacquer acrylic enamel paints stunt ships Such brand names Du pont acrylic lacquer Dizler RM Nasson can used says must finish up acrylic clear enamel over paint will fuel proof Great care must exercised acrylic paints well ventilated spray area mandatory paint mask must used serious permanent injury can experienced type paints should used beginner Get some help experienced use acrylic paints After paint trim applied ink lines its time clear dope applications couple light mist coats needed seal ink lines decals letrasets edges canopy lay coats clear Some very care ful sanding wet 600 between last couple coats clear will help achieve beautiful finish rubbing compound must dope acrylic finishes plane heavy first culprit wood selection course cannot sift through find 4- 5-pound balsa However can cheat some possible build light just mediocre wood Instead using 3/32 wood substitute 1/16 Instead using hollowed block use molded balsa top bottom block See Al Meyers Mustang article March 1978 Model Aviation Instead using inch block top make fuse lage sides er use k hollowed out hollowing blocks easily should able see light 60-watt bulb through wood Regarding woodwork dont go big overhangs elevator rear plane Eliminate anything sticks out behind elevators Make tiny fillets find yourself fillet fits index finger go back sand down fit little finger After finished hollowing out everything blocks tips cowling nose inside lead ing edge etc. go back some Al Rabe once said dont go through surface least couple times blocks youre making thin enough However much glue have using cut amount half Impossible say really must force self use minimum amount glue fiberglass convince yourself will hold Remember really trying build competitive airplane needs hold together air does hit ground should total wreck words Californian Bill Fitzgerald stays together hits ground its built too heavy Sand off much possible un dercoats before painting So go down bare wood patch up Sand sand sand ready paint make first coat silverit will cover wood easily will show up flaws After first time use silver undercoat probably will never go again Sand after coat paint sparing spray gun Sand after first three coats clear finally sand rub out plane much possibleyou can cut up two ounces get consistent engine run Get back basics engine plug fuel muffler tank engine will run block another airplane youve checked loose head screws loose backplate screws clogged spray bar broken needle especially Maxes have go other components Dont hesitant change glow plugs because July1978 91 now cost dollar fuel consistent its home brew good chance could have picked up some water air Theres also chance home brew consistent last batch horrible experience cost two en gines place two Nationals some backyard brew no oil Sure lots smaller fuel distribu tors have good consistent mixes fuel need careful will maintain two gallon cans same fuel side side can run differently seems unlikely muffler could cause inconsistent run except muffler pressure too much too little Experimenting size muffler pressure lines could help some instan ces muffler pressure fitting bad place receiving too much too little pres sure Finally back pressure muf fler may causing engine heat up and/or allowing engine breathe properly good run feel inconsistent runs stem fuel tank fuel lines tank must checked leaks broken tubing clogged lines fuel tubing must go straight line possible pick up tube spray bar No bends twists necessary have removable tank makes much easier adjust tank can moved up down relation spray bar engine can adjusted shims etc recall Bill Werwage inletted mounting beams 1977 Juno could raise engine air plane viewed upright position did get design doubt seriously 25% stunt fliers could plot airfoil mathemati cally accurately scratch doubt have aeronautical design training other what picked up model magazines like sit down sketch out new plane put working drawings using proven wing areas force moment arms tailplane sizes powerplant com ponents Actually canards have seen Nationals finals Open Stunt disguised combat planes have won Walker Cup trophy Ive seen person ever fly Sea Fury Yes know twin-engine stunter placed back 60s 1967 Rich Loomis first Senior best advice can give someone wants depart kit airplane look what works other accom plished fliers well competition over period years sit down draw up couple planes appeal using some full-size plans published planes have Nation als FAI competition adapt rough drawings utilize basic impor tant ingredients must present successful stunt plane wing area related engine size total weight aspect ratio wing force moment-arms both nose tail tailplane size tail vol ume flap size thrust line placement respect wing fuselage side area con trol movement equal unequal wing pan els leading edge sweepback dihedral airfoil size tip configuration Lastly stick design three four versions work out bugs information stunt PAMPA contact Wynn Paul 1640 Maywick Drive Lex Ky. 40504 CL Racing/Lee continued page 36 units acceleration due gravity LDistance measured inches free surface fluid point pressure being measured measured direction force causing acceleration DThe density fluid measured pounds per cubic inch What formula tells us pile up more fluid top pressure feel correspondingly higher model airplane three variables 6-loading due centrifugal force plane flies circle density fuel carried tank dis tance L distance free sur face fuel hole needle valve measured perpendicular line flight Fig illustrates pressure jar water meas uring pressure water various levels jar Note pressure ex hibited independent shape container three variables G L D couple intersting numbers can calculated formula First what kind pressure change would see variable L reduced some value some other value Fig 2 graph shows pressure change water under normal force gravity function depth water much water above point water pressure being meas ured As can seen pressure changes about 0346 psi/in water about psi 10 inches order verify number built simple test apparatus consisted 104 large diameter plastic tubing pressure gauge tachment enabled read pres sures various places column Much relief theoretical values supported reality measured 36 psi bottom column 104 ches water under 1-6 acceleration re sults 36 psi OK much water jar about fuel fuel tank First off have measure G force model hence tank fuel 6 loading can calculated know line length speed plane flying few representative values 6 listed below 6 1467 x MPH2 322 X line length few representative values G listed below MPHGs 525Gs 60 10012731114 10514041228 11015401349 11516841473 12018331604 12519891740 13021511882 13523202030 14024952183 14526762242 ISO28642506 160-flat Goodyear will pulling 1611 6s Slow Rat 160 flat pulling 1409 6s Now crank 6-values first equation along density fuel 0332 lbs/cu find pressure variation 1125-mph Goodyear over /2 psi per slightly less per Slow Rat tank oneinch wide pressure variation fuel level changes full empty will neighborhood pres sure variation will occur regardless whether using pressure fuel system course Slow Rat suction systems allowed psi variation will pressure system Goodyear too its pretty obvious wider tank will result greater variation general rule keep fuel tank narrow possible Tall long OK narrow possible keep pressure change minimum good question ask much does pressure change affect total pressure pressure system order find answer have know pressure created tank using crankcase pressure set up test stand measure found tank pressure untimed crank case tap about 14 psi about 16 psi ball-check used pressure line 92 Model Aviation $ WIN $ USE DAVIS DIESEL CONVERTER AT THE 1978 NATS Fastest Time CL$10000 Highest Time FF$10000 Highest Points /zA Stunt$10000 Davis Diesel Devlopment Inc Box 141 DEPT E MILFORD CT 06460 LiPHONE 203 877-1670