I Old Timers El Dee B Mathews IS UTOPIA Texas Imagine will city four miles wide three deep houses utility poles trees removed leaving nothing streets street signs Such utopia Pyramid Acres far west fringes Fort Worth attended Labor Day Contest Pyramid Acres can flatly say finest flying site free flight RC assist have ever seen model re trieval road rarely requiring 100-yard walk thermals absolutely unreal Any interested free flight whether AMA SAM should make effort Fort Worth next Labor Day weekend Planesmen run super contest trophies Texas-size hospitality pure southern Considering presence Hurricane Anita few hundred miles south us pleasantly surprised find light winds Fort Worth Would believe Mike Fedor won Unlimited Rubber 1067 seconds flying penny plane Thermals monsterous Lift ex tended directions far could see models Mike Birdwells Cumulus actually gained altitude doing consecutive inside loops Bill Baker Quaker up over 40 minutes trying get down resorting spinning Mike Birdwell beat out Bruce Norman 30-second Antique 1559 1515 seconds Unbelievable Lesson Relearned Back bad old days spent time range check ing relay-escapment systems did flying As equipment became reliable reached point no longer bothered range check Well folks have relearned re-installed flight pack Old Timers after pranged project After 20 seconds first official shut-off activated model full up elevator stick down cracked crystal crash resulted limited range situ ation Believe in-flight range checks recommended share since havent noted much range checking lately now turn both switches car carry fuselage flight line range check remove transmitter Continued page 93 ADVANCED CHALLENGER SPAN 51 INCHES CHORD 61/4 INCHES SCALE I 1 2 3 4 5 6 7 8 9 10 30 Model Aviation Finding occasional oldtimer may shed wing trying escape ,un boomer Doc uses spruce top bottom spars vertical webbing between ribs alternates webbing front back spars bay shown picture 85% Taibi Powerhouse w N cJ L Contents P&W Model Products wing kit see textl Gillions spar notches nicely cut fog/rainout year no-contest no-pressure event usually brings out dif ferent types planes usually associ ated contest circuit year no different strictly hangar fly ing Weather kept us close fire Dave Corven did manage 25-minute flightonly because got up before breakfast rest Detroit contin gent smarter noon Saturday clans Detroit Pennsylvania fondue pots going homemade wine sausage laid out does say 10-minute maxes can fun Let rain Saturday evening Don Clark DCRC coordinates annually Cum berland Aero Modeling Society nounced banquet no change schedule next year So circle Nov 4 5 1978 fun soaring week-end whatever weather Dan Pruss Rt 2 Box 490 Plainfield IL 60544 R C Old-Timers/Mathews continued page 30 car others flying fre quency wait got model down staying off controls stalled did spin due wash-out have also gone back placing name phone number models P&W ribs Gene Walloch producing wing stab rib kits 15 old-timer de signs really required build kits plans strip wood Genes line-up includes such favor ites Scientific Mercury Comet Sailplane original Berkley Buc caneer wood quality good band-sawing requires little sanding accurate Send SSAE P&W Model Service PO Box 925 Monrovia CA 91016 complete list spinning Webs Such majority old-timer designs use wing spars con siderable depth relative airfoil Ex ceptions exist course notably multi-spar approach Chet Lanzo common practice use two deep spars bottom side top trend may have associ ated wide use silk double layers bamboo paper covering associated stiffening structure Another factor undoubtedly nitrate dope does continue tighten weeks end newer butyrate dopes Butyrate dope has around since mid 1950s forced use glow plug came along recall such attempts fuel-proof finishes STA HEP Still another possible reason use /s X s such may degen eration quality balsa wood per haps stuff didnt stress relieve much back final possibility course might designers didnt know better What ever reason rea sons fact has become glaringly appar ent have gotten RC assist wings have strong tendency fall off inopportune times As revive grand old designs 40 years ago add radio cover wings plastic film submit flight stresses designers considered crash situation apparent modi fication wing structure para mount importance have never thrill losing wing panel spiralling out boomer dont feel left out Ive done often enough Id like share what Ive found reliable solution simple build adds tre mendous strength resists warping well fitting framework SAM preamble Borrowing heavily George Fuller England free flight Dixielander series has published kitted under disguises Willie Actor ever stirring lessons learned RC glider people generally stealing anything useful Ive using four spar shear-web wing exclusively sev eral years concept appears February 1978 93 fidtIi P R 0 D U CT S N C SVILLE ROAD OW GROVE PA 19090 659-3900 TI SUPERSTAR OF STARTERS Sales zooming past 100000 starter thats turned whole world Has higher torque & RPMs heavy duty long life motor instant-on strip switch safety hand guard 2-year guarantee PROP-LOC AT NEW LOW PRICES Hi-tork spinner smoother idle Cone available 1 1 2 2/4 21/2 2 white black red Now 80c hardware $110 Two-piece aluminum spinner-ette available 5/16-24 1/4-28 6 mm 7 mm threads Now $110 complete see local hobby dealer WI~E almost Stahl design40 years ago t~p tTA OGA 4 lOBts famous 24 1/2 WWdGSPAN 0% FOR PACKING AND POSTAGE VA NESIDENTS ADD 4% TAX RUBBER & CO2 WINNER AT THE 50th NATS Blot 221/2 WINGSPMI $695 Kioud King Ambivalent Dennyplane Miss Arpiem Brigadeer articles skeleton photo 85% Power house photo accompanying months column Depending model size four spruce spars ranging located approximately 30% 70% chord perpendicular other Fulldepth plywood dihedral joiners placed slotting ribs hacksaw stacks appropriate thickness epoxied flush spars Shear webs 1/16 balsa added grain running vertical alternating front rear spars picture illustrates front spars should always webbed rear set may also webbed model stunted weight factor Additional strength can gained D tube sheeting leading edge ever seems add spanwise strength torsional rigidity has stated times bears repeating wing will no stronger rigid after covered heat-shrink material uncovered wing seems flexible uncovered absolutely should covered shiny stuff full set shear webs still doesnt cure flexibility get out silk pre pared pick up pieces Consider four-spar shear-web tech nique next old-timer Dr D B Mathews 506 South Walnut Greens burg KS 67054 Foam/Evans/Lester continued page 35 will take care problem mean time core isnt too bad ways salvage will discussed next issue Sectioning hot-wire method cut ting has limitation cuts must straight line Wings taper angle either LE TE must cut sections glued together Follow same procedure *108 Spo&te 28 WING8PAN S6 INE MODELS 2820 DORR AVE FAIRFAX VA 22030 Send free brochure section described cutting wing panel tip template inboard section also root template outboard section additional section requires additional template tip section also necessary cut very long wings sections due limitations tension necessary keep wire straight power uniform heating wire Dihedral Angle Cutting sim plest ways cutting dihedral angle two-piece wing raise tip prescribed height height can calcu lated angle given make vertical cut root panel can best done after cutting core core still blank can done before sheeting end-cutting jig after sheeting saw and/or sanding block endcutting jig can also done dihedral-angle cutting template angle-cutting tem plate can attached foam blank nails pressed foam can attached cutting jig see Fig 6 template angle half com plement total desired angle both sections must cut match cross sections joint example tendegree angle required template gle will 900 100/2 850 Regardless method should done systematically avoid cutting angle wrong end wrong direction two-panel wings right left sure top up cut root panel except gull wings cut angle outboard section polyhedral wing sure top up cut outer end tip inboard section root outboard section except gull wings same principles apply core cut complete right left panel sectioned polyhedral angle continued Prop Mod/Aycock continued page 31 exact eyeball part just make sure line both blades same OK now have big black line front prop will become high point wood work begins Select rather rough flat wood rasp starting high point work towards leading edge rasp being careful cut away leading edge just take down rather sharp leading edge satisfied same thing again high point towards trailing edge worrying about curved rounded surface just make flat per drawing B Repeat other blade Round off high point shown drawing tips will get quite thin will no way subtract props efficiency should have pile wood dust front now will make some Using 80-grit again hand sand blades rather smooth finish See said hard maple props work best have done respectable job put prop balancing tool should ball park After little practice will able get right money fact time will balanced closer came out box Finish sand blades 280 wet dry dry course done Notice did take anything off back prop blades Thus did alter basic pitch just added airfoil front finished prop should have quite sharp leading trailing edges Leave raw wood finish nothing please Try procedure prop size now using check engine performance airplane flying have found often can go high er pitch prop engine would lug before will turn now author ity Experiment various sizes pitches until get satisfies air remember prop rework can prove itself air ground tach have questions regard ing prop rework please feel free drop line care magazine will happy answer questions Helicopter/B itner continued page 37 altitude 20-60 meters stay within fly course start finish procedures must checked directing official Timing flight can done several ways will tell what method used four timers located south end four north end 94 Model Aviation
Edition: Model Aviation - 1978/02
Page Numbers: 30, 93, 94
I Old Timers El Dee B Mathews IS UTOPIA Texas Imagine will city four miles wide three deep houses utility poles trees removed leaving nothing streets street signs Such utopia Pyramid Acres far west fringes Fort Worth attended Labor Day Contest Pyramid Acres can flatly say finest flying site free flight RC assist have ever seen model re trieval road rarely requiring 100-yard walk thermals absolutely unreal Any interested free flight whether AMA SAM should make effort Fort Worth next Labor Day weekend Planesmen run super contest trophies Texas-size hospitality pure southern Considering presence Hurricane Anita few hundred miles south us pleasantly surprised find light winds Fort Worth Would believe Mike Fedor won Unlimited Rubber 1067 seconds flying penny plane Thermals monsterous Lift ex tended directions far could see models Mike Birdwells Cumulus actually gained altitude doing consecutive inside loops Bill Baker Quaker up over 40 minutes trying get down resorting spinning Mike Birdwell beat out Bruce Norman 30-second Antique 1559 1515 seconds Unbelievable Lesson Relearned Back bad old days spent time range check ing relay-escapment systems did flying As equipment became reliable reached point no longer bothered range check Well folks have relearned re-installed flight pack Old Timers after pranged project After 20 seconds first official shut-off activated model full up elevator stick down cracked crystal crash resulted limited range situ ation Believe in-flight range checks recommended share since havent noted much range checking lately now turn both switches car carry fuselage flight line range check remove transmitter Continued page 93 ADVANCED CHALLENGER SPAN 51 INCHES CHORD 61/4 INCHES SCALE I 1 2 3 4 5 6 7 8 9 10 30 Model Aviation Finding occasional oldtimer may shed wing trying escape ,un boomer Doc uses spruce top bottom spars vertical webbing between ribs alternates webbing front back spars bay shown picture 85% Taibi Powerhouse w N cJ L Contents P&W Model Products wing kit see textl Gillions spar notches nicely cut fog/rainout year no-contest no-pressure event usually brings out dif ferent types planes usually associ ated contest circuit year no different strictly hangar fly ing Weather kept us close fire Dave Corven did manage 25-minute flightonly because got up before breakfast rest Detroit contin gent smarter noon Saturday clans Detroit Pennsylvania fondue pots going homemade wine sausage laid out does say 10-minute maxes can fun Let rain Saturday evening Don Clark DCRC coordinates annually Cum berland Aero Modeling Society nounced banquet no change schedule next year So circle Nov 4 5 1978 fun soaring week-end whatever weather Dan Pruss Rt 2 Box 490 Plainfield IL 60544 R C Old-Timers/Mathews continued page 30 car others flying fre quency wait got model down staying off controls stalled did spin due wash-out have also gone back placing name phone number models P&W ribs Gene Walloch producing wing stab rib kits 15 old-timer de signs really required build kits plans strip wood Genes line-up includes such favor ites Scientific Mercury Comet Sailplane original Berkley Buc caneer wood quality good band-sawing requires little sanding accurate Send SSAE P&W Model Service PO Box 925 Monrovia CA 91016 complete list spinning Webs Such majority old-timer designs use wing spars con siderable depth relative airfoil Ex ceptions exist course notably multi-spar approach Chet Lanzo common practice use two deep spars bottom side top trend may have associ ated wide use silk double layers bamboo paper covering associated stiffening structure Another factor undoubtedly nitrate dope does continue tighten weeks end newer butyrate dopes Butyrate dope has around since mid 1950s forced use glow plug came along recall such attempts fuel-proof finishes STA HEP Still another possible reason use /s X s such may degen eration quality balsa wood per haps stuff didnt stress relieve much back final possibility course might designers didnt know better What ever reason rea sons fact has become glaringly appar ent have gotten RC assist wings have strong tendency fall off inopportune times As revive grand old designs 40 years ago add radio cover wings plastic film submit flight stresses designers considered crash situation apparent modi fication wing structure para mount importance have never thrill losing wing panel spiralling out boomer dont feel left out Ive done often enough Id like share what Ive found reliable solution simple build adds tre mendous strength resists warping well fitting framework SAM preamble Borrowing heavily George Fuller England free flight Dixielander series has published kitted under disguises Willie Actor ever stirring lessons learned RC glider people generally stealing anything useful Ive using four spar shear-web wing exclusively sev eral years concept appears February 1978 93 fidtIi P R 0 D U CT S N C SVILLE ROAD OW GROVE PA 19090 659-3900 TI SUPERSTAR OF STARTERS Sales zooming past 100000 starter thats turned whole world Has higher torque & RPMs heavy duty long life motor instant-on strip switch safety hand guard 2-year guarantee PROP-LOC AT NEW LOW PRICES Hi-tork spinner smoother idle Cone available 1 1 2 2/4 21/2 2 white black red Now 80c hardware $110 Two-piece aluminum spinner-ette available 5/16-24 1/4-28 6 mm 7 mm threads Now $110 complete see local hobby dealer WI~E almost Stahl design40 years ago t~p tTA OGA 4 lOBts famous 24 1/2 WWdGSPAN 0% FOR PACKING AND POSTAGE VA NESIDENTS ADD 4% TAX RUBBER & CO2 WINNER AT THE 50th NATS Blot 221/2 WINGSPMI $695 Kioud King Ambivalent Dennyplane Miss Arpiem Brigadeer articles skeleton photo 85% Power house photo accompanying months column Depending model size four spruce spars ranging located approximately 30% 70% chord perpendicular other Fulldepth plywood dihedral joiners placed slotting ribs hacksaw stacks appropriate thickness epoxied flush spars Shear webs 1/16 balsa added grain running vertical alternating front rear spars picture illustrates front spars should always webbed rear set may also webbed model stunted weight factor Additional strength can gained D tube sheeting leading edge ever seems add spanwise strength torsional rigidity has stated times bears repeating wing will no stronger rigid after covered heat-shrink material uncovered wing seems flexible uncovered absolutely should covered shiny stuff full set shear webs still doesnt cure flexibility get out silk pre pared pick up pieces Consider four-spar shear-web tech nique next old-timer Dr D B Mathews 506 South Walnut Greens burg KS 67054 Foam/Evans/Lester continued page 35 will take care problem mean time core isnt too bad ways salvage will discussed next issue Sectioning hot-wire method cut ting has limitation cuts must straight line Wings taper angle either LE TE must cut sections glued together Follow same procedure *108 Spo&te 28 WING8PAN S6 INE MODELS 2820 DORR AVE FAIRFAX VA 22030 Send free brochure section described cutting wing panel tip template inboard section also root template outboard section additional section requires additional template tip section also necessary cut very long wings sections due limitations tension necessary keep wire straight power uniform heating wire Dihedral Angle Cutting sim plest ways cutting dihedral angle two-piece wing raise tip prescribed height height can calcu lated angle given make vertical cut root panel can best done after cutting core core still blank can done before sheeting end-cutting jig after sheeting saw and/or sanding block endcutting jig can also done dihedral-angle cutting template angle-cutting tem plate can attached foam blank nails pressed foam can attached cutting jig see Fig 6 template angle half com plement total desired angle both sections must cut match cross sections joint example tendegree angle required template gle will 900 100/2 850 Regardless method should done systematically avoid cutting angle wrong end wrong direction two-panel wings right left sure top up cut root panel except gull wings cut angle outboard section polyhedral wing sure top up cut outer end tip inboard section root outboard section except gull wings same principles apply core cut complete right left panel sectioned polyhedral angle continued Prop Mod/Aycock continued page 31 exact eyeball part just make sure line both blades same OK now have big black line front prop will become high point wood work begins Select rather rough flat wood rasp starting high point work towards leading edge rasp being careful cut away leading edge just take down rather sharp leading edge satisfied same thing again high point towards trailing edge worrying about curved rounded surface just make flat per drawing B Repeat other blade Round off high point shown drawing tips will get quite thin will no way subtract props efficiency should have pile wood dust front now will make some Using 80-grit again hand sand blades rather smooth finish See said hard maple props work best have done respectable job put prop balancing tool should ball park After little practice will able get right money fact time will balanced closer came out box Finish sand blades 280 wet dry dry course done Notice did take anything off back prop blades Thus did alter basic pitch just added airfoil front finished prop should have quite sharp leading trailing edges Leave raw wood finish nothing please Try procedure prop size now using check engine performance airplane flying have found often can go high er pitch prop engine would lug before will turn now author ity Experiment various sizes pitches until get satisfies air remember prop rework can prove itself air ground tach have questions regard ing prop rework please feel free drop line care magazine will happy answer questions Helicopter/B itner continued page 37 altitude 20-60 meters stay within fly course start finish procedures must checked directing official Timing flight can done several ways will tell what method used four timers located south end four north end 94 Model Aviation
Edition: Model Aviation - 1978/02
Page Numbers: 30, 93, 94
I Old Timers El Dee B Mathews IS UTOPIA Texas Imagine will city four miles wide three deep houses utility poles trees removed leaving nothing streets street signs Such utopia Pyramid Acres far west fringes Fort Worth attended Labor Day Contest Pyramid Acres can flatly say finest flying site free flight RC assist have ever seen model re trieval road rarely requiring 100-yard walk thermals absolutely unreal Any interested free flight whether AMA SAM should make effort Fort Worth next Labor Day weekend Planesmen run super contest trophies Texas-size hospitality pure southern Considering presence Hurricane Anita few hundred miles south us pleasantly surprised find light winds Fort Worth Would believe Mike Fedor won Unlimited Rubber 1067 seconds flying penny plane Thermals monsterous Lift ex tended directions far could see models Mike Birdwells Cumulus actually gained altitude doing consecutive inside loops Bill Baker Quaker up over 40 minutes trying get down resorting spinning Mike Birdwell beat out Bruce Norman 30-second Antique 1559 1515 seconds Unbelievable Lesson Relearned Back bad old days spent time range check ing relay-escapment systems did flying As equipment became reliable reached point no longer bothered range check Well folks have relearned re-installed flight pack Old Timers after pranged project After 20 seconds first official shut-off activated model full up elevator stick down cracked crystal crash resulted limited range situ ation Believe in-flight range checks recommended share since havent noted much range checking lately now turn both switches car carry fuselage flight line range check remove transmitter Continued page 93 ADVANCED CHALLENGER SPAN 51 INCHES CHORD 61/4 INCHES SCALE I 1 2 3 4 5 6 7 8 9 10 30 Model Aviation Finding occasional oldtimer may shed wing trying escape ,un boomer Doc uses spruce top bottom spars vertical webbing between ribs alternates webbing front back spars bay shown picture 85% Taibi Powerhouse w N cJ L Contents P&W Model Products wing kit see textl Gillions spar notches nicely cut fog/rainout year no-contest no-pressure event usually brings out dif ferent types planes usually associ ated contest circuit year no different strictly hangar fly ing Weather kept us close fire Dave Corven did manage 25-minute flightonly because got up before breakfast rest Detroit contin gent smarter noon Saturday clans Detroit Pennsylvania fondue pots going homemade wine sausage laid out does say 10-minute maxes can fun Let rain Saturday evening Don Clark DCRC coordinates annually Cum berland Aero Modeling Society nounced banquet no change schedule next year So circle Nov 4 5 1978 fun soaring week-end whatever weather Dan Pruss Rt 2 Box 490 Plainfield IL 60544 R C Old-Timers/Mathews continued page 30 car others flying fre quency wait got model down staying off controls stalled did spin due wash-out have also gone back placing name phone number models P&W ribs Gene Walloch producing wing stab rib kits 15 old-timer de signs really required build kits plans strip wood Genes line-up includes such favor ites Scientific Mercury Comet Sailplane original Berkley Buc caneer wood quality good band-sawing requires little sanding accurate Send SSAE P&W Model Service PO Box 925 Monrovia CA 91016 complete list spinning Webs Such majority old-timer designs use wing spars con siderable depth relative airfoil Ex ceptions exist course notably multi-spar approach Chet Lanzo common practice use two deep spars bottom side top trend may have associ ated wide use silk double layers bamboo paper covering associated stiffening structure Another factor undoubtedly nitrate dope does continue tighten weeks end newer butyrate dopes Butyrate dope has around since mid 1950s forced use glow plug came along recall such attempts fuel-proof finishes STA HEP Still another possible reason use /s X s such may degen eration quality balsa wood per haps stuff didnt stress relieve much back final possibility course might designers didnt know better What ever reason rea sons fact has become glaringly appar ent have gotten RC assist wings have strong tendency fall off inopportune times As revive grand old designs 40 years ago add radio cover wings plastic film submit flight stresses designers considered crash situation apparent modi fication wing structure para mount importance have never thrill losing wing panel spiralling out boomer dont feel left out Ive done often enough Id like share what Ive found reliable solution simple build adds tre mendous strength resists warping well fitting framework SAM preamble Borrowing heavily George Fuller England free flight Dixielander series has published kitted under disguises Willie Actor ever stirring lessons learned RC glider people generally stealing anything useful Ive using four spar shear-web wing exclusively sev eral years concept appears February 1978 93 fidtIi P R 0 D U CT S N C SVILLE ROAD OW GROVE PA 19090 659-3900 TI SUPERSTAR OF STARTERS Sales zooming past 100000 starter thats turned whole world Has higher torque & RPMs heavy duty long life motor instant-on strip switch safety hand guard 2-year guarantee PROP-LOC AT NEW LOW PRICES Hi-tork spinner smoother idle Cone available 1 1 2 2/4 21/2 2 white black red Now 80c hardware $110 Two-piece aluminum spinner-ette available 5/16-24 1/4-28 6 mm 7 mm threads Now $110 complete see local hobby dealer WI~E almost Stahl design40 years ago t~p tTA OGA 4 lOBts famous 24 1/2 WWdGSPAN 0% FOR PACKING AND POSTAGE VA NESIDENTS ADD 4% TAX RUBBER & CO2 WINNER AT THE 50th NATS Blot 221/2 WINGSPMI $695 Kioud King Ambivalent Dennyplane Miss Arpiem Brigadeer articles skeleton photo 85% Power house photo accompanying months column Depending model size four spruce spars ranging located approximately 30% 70% chord perpendicular other Fulldepth plywood dihedral joiners placed slotting ribs hacksaw stacks appropriate thickness epoxied flush spars Shear webs 1/16 balsa added grain running vertical alternating front rear spars picture illustrates front spars should always webbed rear set may also webbed model stunted weight factor Additional strength can gained D tube sheeting leading edge ever seems add spanwise strength torsional rigidity has stated times bears repeating wing will no stronger rigid after covered heat-shrink material uncovered wing seems flexible uncovered absolutely should covered shiny stuff full set shear webs still doesnt cure flexibility get out silk pre pared pick up pieces Consider four-spar shear-web tech nique next old-timer Dr D B Mathews 506 South Walnut Greens burg KS 67054 Foam/Evans/Lester continued page 35 will take care problem mean time core isnt too bad ways salvage will discussed next issue Sectioning hot-wire method cut ting has limitation cuts must straight line Wings taper angle either LE TE must cut sections glued together Follow same procedure *108 Spo&te 28 WING8PAN S6 INE MODELS 2820 DORR AVE FAIRFAX VA 22030 Send free brochure section described cutting wing panel tip template inboard section also root template outboard section additional section requires additional template tip section also necessary cut very long wings sections due limitations tension necessary keep wire straight power uniform heating wire Dihedral Angle Cutting sim plest ways cutting dihedral angle two-piece wing raise tip prescribed height height can calcu lated angle given make vertical cut root panel can best done after cutting core core still blank can done before sheeting end-cutting jig after sheeting saw and/or sanding block endcutting jig can also done dihedral-angle cutting template angle-cutting tem plate can attached foam blank nails pressed foam can attached cutting jig see Fig 6 template angle half com plement total desired angle both sections must cut match cross sections joint example tendegree angle required template gle will 900 100/2 850 Regardless method should done systematically avoid cutting angle wrong end wrong direction two-panel wings right left sure top up cut root panel except gull wings cut angle outboard section polyhedral wing sure top up cut outer end tip inboard section root outboard section except gull wings same principles apply core cut complete right left panel sectioned polyhedral angle continued Prop Mod/Aycock continued page 31 exact eyeball part just make sure line both blades same OK now have big black line front prop will become high point wood work begins Select rather rough flat wood rasp starting high point work towards leading edge rasp being careful cut away leading edge just take down rather sharp leading edge satisfied same thing again high point towards trailing edge worrying about curved rounded surface just make flat per drawing B Repeat other blade Round off high point shown drawing tips will get quite thin will no way subtract props efficiency should have pile wood dust front now will make some Using 80-grit again hand sand blades rather smooth finish See said hard maple props work best have done respectable job put prop balancing tool should ball park After little practice will able get right money fact time will balanced closer came out box Finish sand blades 280 wet dry dry course done Notice did take anything off back prop blades Thus did alter basic pitch just added airfoil front finished prop should have quite sharp leading trailing edges Leave raw wood finish nothing please Try procedure prop size now using check engine performance airplane flying have found often can go high er pitch prop engine would lug before will turn now author ity Experiment various sizes pitches until get satisfies air remember prop rework can prove itself air ground tach have questions regard ing prop rework please feel free drop line care magazine will happy answer questions Helicopter/B itner continued page 37 altitude 20-60 meters stay within fly course start finish procedures must checked directing official Timing flight can done several ways will tell what method used four timers located south end four north end 94 Model Aviation