U Richard Weber Howt@t muffler know muffler pressure working properly Check makeshift manometer MANY PEOPLE using muffler pres sure fuel tanks provides simple way assist carburetor fuel draw reduces percentage variation fuel pressure carburetor arises climbing diving thereby main taining constant fuel-air mixture muffler pressure work properly must higher atmospheric pressure may case muffler rpm have seen several instances muf flers produce suction pressure tap certain rpm owners quite perplexed about engines would die lean after two minutes air flier set mixture rich enough keep running got very short runs evidently part fuel being pressure sucked directly fuel tank muffler perhaps temporarily collaps ing fuel tank Testing muffler pressure easy makeshift manometer Take several feet large clear fuel line fill fuel Arrange tubing lii shape shown diagram Connect end manometer muffler pressure tap leave other end open simplify measurements can attach tubing vertical yardstick loose rubberIC 8 bands Run engine check fuel level two sides manometer various rpm muffler pressure given difference H fuel height two sides tubing graph shows pressure measured K&B 40 Series 71 Data two muf flers two props given KO muffler has closed expansion chamber pressure tap stack connects engine Semco flowCon tinued page 96 K B 40 SERIES 71 MUFFLER AKO PROP 10-6 10-6 9-6 ABC 68 M thousands effect pressure inches fuel measuredl engine rpm illustrated graph using K&B 40 Series 71 engine end representative mufflers propellers checking fuel level both sides manometer various rpm pressure measured difference H fuel heights MANOMETER February 1978 41 U 1214 16 authors simple test rig operating principle made evident drawing quite possible experience suction pressure tap resulting lean short runs Muffler pressure must higher atmospheric pressure shell spar will butt against spar use toothpicks align hold spar same stabilizer Use glass cloth around spar added strength several layers glass cloth paint tails of airplanes because weight build up possibility warping tail surface sealed epoxy glue rubbed wood unpainted wood surfaces Fuel Tank suction fuel system very simple should provide very constant engine runs tank itself can easily made 010 tin can ordered John Newton Speed Racing Products completely assembled ready bolt airplane Takeoff Dolly Any three-wheel dolly front wheel spread close wing span should prove satisfactory lift-out type two guide pins extending two three inches above wingone mid-wing other close fuse lage Some weight might needed close outboard wheel just depends dolly design Engines Fuel Props use essentially stock Rossi Rear Rotor 15s Except bar stock head engine stock use bar-stock head save price Rossi inserts Rossi insert faster can keep element whole run stock Rossi stock 6-7 Rev-Up prop 65% nitro can very consistently put 162-mph bracket nitro Rossi pipe short will go 170 mph range achievable consistently standard fuel mix used usually 65-75% nitro 20% oils rest alco hol have always used least 5%-10% castor oil fuel other oil content being synthetic oil Rev-Up 6-7 prop seems about right 65-75% nitro fuel weather conditions dont stop Experiment Flying The airplane very smooth flying should present no real problems takeoff run hold some down elevator until flying speed approached ease neutral airplane should lift off easily Dont let airplane climb too high Keep about 5 feet have questions problems feel free contact us John Newton 2154 Los Padres Rowland Heights CA 91748 Jim Wade 1853 Yettford Rd Vista CA 92083 Stripper/Lidberg continued page 56 As example handy strip per can recently built unlimited rubber model long geodetically braced fuselage Cross braces 1/16 X 3/16 local hobby shop out size bought sheet 1/16 X 2 Using stripper made up 3/16 width 1/16 depth able cut 10 pieces 3/l6 wide piece about /8 wide left over strip square edges uniform width con struction sanding finished fuse lage simplified Looking again yield piece sheet balsa shows considerable savings can made 2 sheet cost 5l yielded 10 strips would have cost ll $110 Thats bad just few minutes work addition able finish model making extra trip search strip wood An Easy Balsa Stripper can made just size 15 20 minutes can make half dozen commonly used sizes Mark width stripper ready reference prevent throwing strippers out scrap color markers colored paint strip pers can used two ways Either way works better sheet balsa has good straight edge sure check first knife/straightedge routine maybe just sanding block can used produce straigbt-edged sheet method prefer cutting strips shown photos sheet held down left hand stripper used right hand Keep slight amount pressure toward sheet keep strips consistent width may prefer holding stripper left hand blade pointing up pushing sheet through right hand Rubbing surfaces stripper slide sheet balsa lightly small dry bar soap will speed up process small sharpening stone can used touch up blade new stripper can quickly made blade chipped too dull dont need strip balsa right now remember Easy Balsa Stripper next time need some Friday Saturday night after hobby shop closes hope youll find handy M uffler/Weber con tinued page 41 through muffler has pressure tap main body graph can seen expansion chamber supplies pressure flow-through other comparison between 10-6 9-6 Semco shows pressure given rpm 10-6 full throt tIe pressure slightly higher 9-6 testing muffler pressure manometer fuel level should higher open side U indicates muffler pressure exceeding atmospheric pressure fuel level higher muffler side U muffler has suc tion instead positive pressure solve problem try different location pressure tap get different muffler just forget about using muffler pressure muffler behaves well will show positive pressure rpm increasing higher rpm found examples graph same simple manometer setup can also used check other pressures such crankcase pressure fuel pump pres sure FF Duration/Meuser continued page 54 awards must somehow represent signifi cant contribution sport perhaps evidenced outstanding contest record under exceptional circumstan ces awards have presented models intended competition awards have made things other specific models name few Pennyplane event Rossi 15 Normale engine Peanut-Scale concept Seelig timer Old-Timer movement Both domestic foreign candidates eligible Supply much information can Xeroxes articles lists contest wins National records whatever cant supply send name designer whatever do soon Time awastin New Digest Editor Free Flight NFFS Digest known affectionately simply Digest has new editor Several fact After being editor seven months just really getting swing Keith Varnau found necessary give up job Bob Stalick Tom Hutchin son put together interim issue Lee Vicki Hines put out another Now its hands John Oldenkamp lives 654 India St San Diego CA 92101 Send him good stuff photos sketches stories articles contest results reports whatever Im sure hed appreciate receiving club newsletters too 96 Model Aviation FINE QUALITY KITS AND ACCESSORIES Qj2Ij SCALE PLASTIC KITS FLYING MODEL ACCESSORIES SCALE PILOTS INE GUNS WHEELS & WHEEL PANTS ENGINE KITS & CYLINDERS SEND SOt FOR COMPLETE CATALOG Dept MA ,18 1 PAWNEE STREET 4iLIJAMSSAN MARCOS CALIPORNIA 9
Edition: Model Aviation - 1978/02
Page Numbers: 41, 96
Edition: Model Aviation - 1978/02
Page Numbers: 41, 96
U Richard Weber Howt@t muffler know muffler pressure working properly Check makeshift manometer MANY PEOPLE using muffler pres sure fuel tanks provides simple way assist carburetor fuel draw reduces percentage variation fuel pressure carburetor arises climbing diving thereby main taining constant fuel-air mixture muffler pressure work properly must higher atmospheric pressure may case muffler rpm have seen several instances muf flers produce suction pressure tap certain rpm owners quite perplexed about engines would die lean after two minutes air flier set mixture rich enough keep running got very short runs evidently part fuel being pressure sucked directly fuel tank muffler perhaps temporarily collaps ing fuel tank Testing muffler pressure easy makeshift manometer Take several feet large clear fuel line fill fuel Arrange tubing lii shape shown diagram Connect end manometer muffler pressure tap leave other end open simplify measurements can attach tubing vertical yardstick loose rubberIC 8 bands Run engine check fuel level two sides manometer various rpm muffler pressure given difference H fuel height two sides tubing graph shows pressure measured K&B 40 Series 71 Data two muf flers two props given KO muffler has closed expansion chamber pressure tap stack connects engine Semco flowCon tinued page 96 K B 40 SERIES 71 MUFFLER AKO PROP 10-6 10-6 9-6 ABC 68 M thousands effect pressure inches fuel measuredl engine rpm illustrated graph using K&B 40 Series 71 engine end representative mufflers propellers checking fuel level both sides manometer various rpm pressure measured difference H fuel heights MANOMETER February 1978 41 U 1214 16 authors simple test rig operating principle made evident drawing quite possible experience suction pressure tap resulting lean short runs Muffler pressure must higher atmospheric pressure shell spar will butt against spar use toothpicks align hold spar same stabilizer Use glass cloth around spar added strength several layers glass cloth paint tails of airplanes because weight build up possibility warping tail surface sealed epoxy glue rubbed wood unpainted wood surfaces Fuel Tank suction fuel system very simple should provide very constant engine runs tank itself can easily made 010 tin can ordered John Newton Speed Racing Products completely assembled ready bolt airplane Takeoff Dolly Any three-wheel dolly front wheel spread close wing span should prove satisfactory lift-out type two guide pins extending two three inches above wingone mid-wing other close fuse lage Some weight might needed close outboard wheel just depends dolly design Engines Fuel Props use essentially stock Rossi Rear Rotor 15s Except bar stock head engine stock use bar-stock head save price Rossi inserts Rossi insert faster can keep element whole run stock Rossi stock 6-7 Rev-Up prop 65% nitro can very consistently put 162-mph bracket nitro Rossi pipe short will go 170 mph range achievable consistently standard fuel mix used usually 65-75% nitro 20% oils rest alco hol have always used least 5%-10% castor oil fuel other oil content being synthetic oil Rev-Up 6-7 prop seems about right 65-75% nitro fuel weather conditions dont stop Experiment Flying The airplane very smooth flying should present no real problems takeoff run hold some down elevator until flying speed approached ease neutral airplane should lift off easily Dont let airplane climb too high Keep about 5 feet have questions problems feel free contact us John Newton 2154 Los Padres Rowland Heights CA 91748 Jim Wade 1853 Yettford Rd Vista CA 92083 Stripper/Lidberg continued page 56 As example handy strip per can recently built unlimited rubber model long geodetically braced fuselage Cross braces 1/16 X 3/16 local hobby shop out size bought sheet 1/16 X 2 Using stripper made up 3/16 width 1/16 depth able cut 10 pieces 3/l6 wide piece about /8 wide left over strip square edges uniform width con struction sanding finished fuse lage simplified Looking again yield piece sheet balsa shows considerable savings can made 2 sheet cost 5l yielded 10 strips would have cost ll $110 Thats bad just few minutes work addition able finish model making extra trip search strip wood An Easy Balsa Stripper can made just size 15 20 minutes can make half dozen commonly used sizes Mark width stripper ready reference prevent throwing strippers out scrap color markers colored paint strip pers can used two ways Either way works better sheet balsa has good straight edge sure check first knife/straightedge routine maybe just sanding block can used produce straigbt-edged sheet method prefer cutting strips shown photos sheet held down left hand stripper used right hand Keep slight amount pressure toward sheet keep strips consistent width may prefer holding stripper left hand blade pointing up pushing sheet through right hand Rubbing surfaces stripper slide sheet balsa lightly small dry bar soap will speed up process small sharpening stone can used touch up blade new stripper can quickly made blade chipped too dull dont need strip balsa right now remember Easy Balsa Stripper next time need some Friday Saturday night after hobby shop closes hope youll find handy M uffler/Weber con tinued page 41 through muffler has pressure tap main body graph can seen expansion chamber supplies pressure flow-through other comparison between 10-6 9-6 Semco shows pressure given rpm 10-6 full throt tIe pressure slightly higher 9-6 testing muffler pressure manometer fuel level should higher open side U indicates muffler pressure exceeding atmospheric pressure fuel level higher muffler side U muffler has suc tion instead positive pressure solve problem try different location pressure tap get different muffler just forget about using muffler pressure muffler behaves well will show positive pressure rpm increasing higher rpm found examples graph same simple manometer setup can also used check other pressures such crankcase pressure fuel pump pres sure FF Duration/Meuser continued page 54 awards must somehow represent signifi cant contribution sport perhaps evidenced outstanding contest record under exceptional circumstan ces awards have presented models intended competition awards have made things other specific models name few Pennyplane event Rossi 15 Normale engine Peanut-Scale concept Seelig timer Old-Timer movement Both domestic foreign candidates eligible Supply much information can Xeroxes articles lists contest wins National records whatever cant supply send name designer whatever do soon Time awastin New Digest Editor Free Flight NFFS Digest known affectionately simply Digest has new editor Several fact After being editor seven months just really getting swing Keith Varnau found necessary give up job Bob Stalick Tom Hutchin son put together interim issue Lee Vicki Hines put out another Now its hands John Oldenkamp lives 654 India St San Diego CA 92101 Send him good stuff photos sketches stories articles contest results reports whatever Im sure hed appreciate receiving club newsletters too 96 Model Aviation FINE QUALITY KITS AND ACCESSORIES Qj2Ij SCALE PLASTIC KITS FLYING MODEL ACCESSORIES SCALE PILOTS INE GUNS WHEELS & WHEEL PANTS ENGINE KITS & CYLINDERS SEND SOt FOR COMPLETE CATALOG Dept MA ,18 1 PAWNEE STREET 4iLIJAMSSAN MARCOS CALIPORNIA 9
