SAFElY S FIRST Lets learn bit subject model air craft electric power lines CL models thunderstorms John Preston ONE pleasures writing monthly column receiving letters response readers Whether complimentary derogatory really doesnt matter since either type shows people reading stuff write taking time respond admit however prefer compliments criticism As happens mail shows positive reception column thank writers letters interesting accounts safety-related experiences apologies go may have received acknowledgement letters just hours day like build models too Once have letter reader disagreed what have said Such letterwas received K L McClenahan electrical engineer takes issue content column concerning electrocution hazards Specifically charged making several statements either false misleading dangerous plead guilty charge perhaps did under emphasize some points trying make example subject far arc may jump high voltage source ground states 70000 volts per inch represents about maximum dielectric strength dry air DC voltage applied across sphere-sphere gap air standard temperature pressure AC voltage applied different electrode shapes different atmospheric conditions dielectric strength gap may much reduced Power system engineers use clearances about inch per 1000 volts electrical equipment accepting fact flashover will occur under some conditions Under some conditions such remote lightning strike overhead line voltages far above nominal system voltage may occur electrical system have agree distance arc can occur between source high voltage grounded object could well much greater 70000 volts per inch figure quoted figures provided electrical engineer also read over finished column check accuracy So much choice electrical engineers consulted National Electrical Code see could obtain further information clearances required high voltage power lines found document almost totally useless purposes just too caveats attached figures found Let us just say power lines either border cross flying field keep well away better still find another field Under no circumstances ever get yourself model closer lines would walked underneath subject lightning strikes weve two other modelers mention effects thunder storms vicinity control line flying Perhaps following excerpt letter sent us Bruce Denney Ft Smith AR best illustrates phenomenon l know enough fly right under thunderstorm learned lesson about flying close flying stunter day thunderstorm about four five miles away could see lot lightning horizon clear skies above too much wind yet figured about half hour before storm would reach fired up took off first couple laps about 20 ft high went OK tried wingover As model went through vertical about 65 feet high got h - shocked out After kept low after landing packed up went home day think must lot static electricity air four five miles away thunderstorm conversation noted CL aero batic scale flier Keith Trostle heard similar story electric shock being received through lines handle before visible lightning sounds thunder lesson learned two shocking experiences obvious Dont fly time thunderstorm threatens would also apply RC FF fliers too Returning letter K L McClenahan following comment warning regard battery chargers use dropping resistors instead transformers Anyone has battery charger uses dropping resistors lieu isolation trans former should stomp throw pieces trash can Such devices extremely haz ardous should never make recommendation concerning except destroyed did ponder subject some before giving instructions re caution using such device reason didnt suggest should stomp simple economics theorized suggestions would ignored people decided continue use might follow safety instructions safest place chargers dropping resistors instead transformers indeed trash can Before leaving subject electrical hazards would like quote AP wire story sent us Doug Dahlke Doug read January 1966 issue Flying Models maga zine Watch Power Lines Take heed shores jolly old England London comes Associated Press release MODEL AIRPLANE DIVES COWS ELECTROCUTED London AP model airplane got Out control Wednesday nose dived fanner William Watts cow pasture its way down brought 11 000 volt cable ran across farm live cable dropped four pedigree cows feeding marshy pasture expen sive quartet electrocuted expectant mothers broken cable blacked out Rainham village Watts Berwick Pond farm happened London suburb Hornchurch Andrew Burton 14 playing model plane model tiny gasoline motor fourfoot wing-spread climbed 500 feet Andrew controlled radio thought plane failed respond Andrews signals disap peared Five miles away ran out gas made its dive plane Andrews name address Two hours later pair police cars drove up front house told what happened amazed said Andrew think plane got out control because actuator controlled rudder faulty Im changing mechanism Said Andrews mother Mrs Sylvia Burton Andrew Continued page 115 52 Model Aviation 10fl9 ago newI mi ecrum mouei bu er wheel retainers propane torch gory details column storage containers microfilm models box essentially airtight must no cracks can leak air gusts would damage model next requirement fits boxesthere must enough strength sides box resist reasonable amount weight being piled top box External markings should specify side box facing up during transport remarks follow assume box position possible model box built corregated cardboard should have double thickness sides However assuming box lid slips over rest box like lid ofshoebox easy get double-thickness sidewalls Simply make lid same depth rest box outlined below double-thickness sidewalls come automatically maximize loadbearing capacity top bottom box center divider double-thickness card board can installed hard realize easy cardboard boxes build until youve tried Perhaps hardest single part find large sheet flat warped weathered corregated cardboard paying spoils fun have big big minimum dimension cardboard sheet required equal width finished box plus twice depth plus some working room same fashion length finished box plus twice box depth equals length cardboard needed Fig shows basic layout bottom box Three factors control well box parts will fit together accurate measurements straight lines careful workmanship Begin being sure start 900 angle corner layout best way to measure three units along end card board point B four units C along adjacent side shown left end Fig 1 Make trial measure ment B C move C line parallel side AB until distance BC exactly five units long AC four units long Trim side cardboard until lines AB AC form 900 angle cardboard Extend lines AB AC good straightedge lay Out required cardboard size being sure keep opposite sides parallel Mark out dashed lines shown Fig 1 cut four short segments indicated Use long straightedge rounded rod dowel plastic case ballpoint pen will work nicely crease lines marked Fl Hold box bottom flat flap bent up time Careful work point will insure fold single straight line Lay sides flat again offset lines F2 exactly thickness cardboard box bottom lines offset toward center sheet new lines scored bent before two flaps fold inside box leaving smooth sides ends box Very carefully fold box shape tape togetherwithmaskingtape Use awhite furniture glue glue flaps side hold things flat straight weights Glue flap time sure glue dry before removing weights After four flaps made make box top exactly like bottom except must allow enough extra length dimen sions top will snug fit orerthe bottom Note F2 folds will offset toward edge cardboard box topthis allows flaps fold outside box isnt pretty doubled flap area also greatly strengthens box will hold bigger weights piled top Next timefinishing box fixtures Models Overseas Indoor fliers active Scandinavian countries especially FAL events Two photos Sweden make clear indoor fliers same world overif didnt reveal photos came could guess Bud Tenny P0 Box 545 Richardson TX 75080 Safety/Preston Continued page 52 husband went see farmer took very wellconsidering farmer said Andrew father may have heard last freak accident So have Im sure some may have seen article originally appeared FM magazine wonder Burtons did hear farmer carried liability insurance also wonder Andrew finished changing mechanism presumably escapement single channel radio would guess could buy lot radios price quartette pregnant pedigree cows moral ofthis story Should requirement RC models equipped device currently available retard throttle upon loss transmitter signal doesnt generate some mail nothing will wind up safety column month publish story behind picture charred ukie also Doug Dahlke friend Dougs soldering wheel retainers onto model Mustang II using propane torch/iron model recently finished nitrate dope sitting balsa-dustcovered workbench modeler .tilted nozzle too far downward liquid propane ran forward causing burp hand airplane Hand quickly put out plane went up seconds Fortunately model burned up suppose model hanging over workbench some cans dope fuel sitting close Modelers work areas often surrounded combustible materials such balsa scrap box cleaning rags etc Take look around space imagine what might happen accidentally started fire extinguisher hand Perhaps its time perform long overdue annual cleanup Next month will discuss some other ways can destroy model maybe yourself fire Till think safety Before signing off month would like announce new award Senator Proxmire has Golden Fleece Laugh-In its Fickle Finger harmony logo calling Dissected Digit Award recipient will someone involved incident activity opinion best interests safety unsure just should receive dubious honor being first upon award bestowed turn page 23 April issue Model Aviation will see bottom left page photograph practice appears less prudent Although caption states model being cleaned presence pump equipped fuel can suggests de-fueling operation So either father captive playpen column writer sorry Ron unobservant Assistant Editor noble publisher its full gotcha Carl goes first award Dissected Digit May better future knows could next honor role Have safe month John Preston 7012 Elvira Court Falls Church V4 22042 Hills Are Alive/Groves Continued page 59 years old went war exper ience changed Western Front contest models military aircraft participating nations 1914-1918 war Because Hill Country grounds ideally suited dicey squirrelly planes WWI first Western Front contest held nine years ago Since has become perhaps longest-running June 1980 115 QUARTER SCALE 3 OT GIANT SCALE SPANDAU & VICKERS PLASTIC GUN KITS STANDARD PILOT COMPLETE WITH GOGGLES GNOME ROTARY ENGINE CYLINDERS VINTAGE GOLDEN AGE & BALLOON TIRE WHEELS w 3303 IN" SEND 5O FOR COMPLETE CATALOG MA 181 PAWNEE STREET SAN MARCOS CA 9 NEW BY POPULAR DEMAND
Edition: Model Aviation - 1980/06
Page Numbers: 52, 115
SAFElY S FIRST Lets learn bit subject model air craft electric power lines CL models thunderstorms John Preston ONE pleasures writing monthly column receiving letters response readers Whether complimentary derogatory really doesnt matter since either type shows people reading stuff write taking time respond admit however prefer compliments criticism As happens mail shows positive reception column thank writers letters interesting accounts safety-related experiences apologies go may have received acknowledgement letters just hours day like build models too Once have letter reader disagreed what have said Such letterwas received K L McClenahan electrical engineer takes issue content column concerning electrocution hazards Specifically charged making several statements either false misleading dangerous plead guilty charge perhaps did under emphasize some points trying make example subject far arc may jump high voltage source ground states 70000 volts per inch represents about maximum dielectric strength dry air DC voltage applied across sphere-sphere gap air standard temperature pressure AC voltage applied different electrode shapes different atmospheric conditions dielectric strength gap may much reduced Power system engineers use clearances about inch per 1000 volts electrical equipment accepting fact flashover will occur under some conditions Under some conditions such remote lightning strike overhead line voltages far above nominal system voltage may occur electrical system have agree distance arc can occur between source high voltage grounded object could well much greater 70000 volts per inch figure quoted figures provided electrical engineer also read over finished column check accuracy So much choice electrical engineers consulted National Electrical Code see could obtain further information clearances required high voltage power lines found document almost totally useless purposes just too caveats attached figures found Let us just say power lines either border cross flying field keep well away better still find another field Under no circumstances ever get yourself model closer lines would walked underneath subject lightning strikes weve two other modelers mention effects thunder storms vicinity control line flying Perhaps following excerpt letter sent us Bruce Denney Ft Smith AR best illustrates phenomenon l know enough fly right under thunderstorm learned lesson about flying close flying stunter day thunderstorm about four five miles away could see lot lightning horizon clear skies above too much wind yet figured about half hour before storm would reach fired up took off first couple laps about 20 ft high went OK tried wingover As model went through vertical about 65 feet high got h - shocked out After kept low after landing packed up went home day think must lot static electricity air four five miles away thunderstorm conversation noted CL aero batic scale flier Keith Trostle heard similar story electric shock being received through lines handle before visible lightning sounds thunder lesson learned two shocking experiences obvious Dont fly time thunderstorm threatens would also apply RC FF fliers too Returning letter K L McClenahan following comment warning regard battery chargers use dropping resistors instead transformers Anyone has battery charger uses dropping resistors lieu isolation trans former should stomp throw pieces trash can Such devices extremely haz ardous should never make recommendation concerning except destroyed did ponder subject some before giving instructions re caution using such device reason didnt suggest should stomp simple economics theorized suggestions would ignored people decided continue use might follow safety instructions safest place chargers dropping resistors instead transformers indeed trash can Before leaving subject electrical hazards would like quote AP wire story sent us Doug Dahlke Doug read January 1966 issue Flying Models maga zine Watch Power Lines Take heed shores jolly old England London comes Associated Press release MODEL AIRPLANE DIVES COWS ELECTROCUTED London AP model airplane got Out control Wednesday nose dived fanner William Watts cow pasture its way down brought 11 000 volt cable ran across farm live cable dropped four pedigree cows feeding marshy pasture expen sive quartet electrocuted expectant mothers broken cable blacked out Rainham village Watts Berwick Pond farm happened London suburb Hornchurch Andrew Burton 14 playing model plane model tiny gasoline motor fourfoot wing-spread climbed 500 feet Andrew controlled radio thought plane failed respond Andrews signals disap peared Five miles away ran out gas made its dive plane Andrews name address Two hours later pair police cars drove up front house told what happened amazed said Andrew think plane got out control because actuator controlled rudder faulty Im changing mechanism Said Andrews mother Mrs Sylvia Burton Andrew Continued page 115 52 Model Aviation 10fl9 ago newI mi ecrum mouei bu er wheel retainers propane torch gory details column storage containers microfilm models box essentially airtight must no cracks can leak air gusts would damage model next requirement fits boxesthere must enough strength sides box resist reasonable amount weight being piled top box External markings should specify side box facing up during transport remarks follow assume box position possible model box built corregated cardboard should have double thickness sides However assuming box lid slips over rest box like lid ofshoebox easy get double-thickness sidewalls Simply make lid same depth rest box outlined below double-thickness sidewalls come automatically maximize loadbearing capacity top bottom box center divider double-thickness card board can installed hard realize easy cardboard boxes build until youve tried Perhaps hardest single part find large sheet flat warped weathered corregated cardboard paying spoils fun have big big minimum dimension cardboard sheet required equal width finished box plus twice depth plus some working room same fashion length finished box plus twice box depth equals length cardboard needed Fig shows basic layout bottom box Three factors control well box parts will fit together accurate measurements straight lines careful workmanship Begin being sure start 900 angle corner layout best way to measure three units along end card board point B four units C along adjacent side shown left end Fig 1 Make trial measure ment B C move C line parallel side AB until distance BC exactly five units long AC four units long Trim side cardboard until lines AB AC form 900 angle cardboard Extend lines AB AC good straightedge lay Out required cardboard size being sure keep opposite sides parallel Mark out dashed lines shown Fig 1 cut four short segments indicated Use long straightedge rounded rod dowel plastic case ballpoint pen will work nicely crease lines marked Fl Hold box bottom flat flap bent up time Careful work point will insure fold single straight line Lay sides flat again offset lines F2 exactly thickness cardboard box bottom lines offset toward center sheet new lines scored bent before two flaps fold inside box leaving smooth sides ends box Very carefully fold box shape tape togetherwithmaskingtape Use awhite furniture glue glue flaps side hold things flat straight weights Glue flap time sure glue dry before removing weights After four flaps made make box top exactly like bottom except must allow enough extra length dimen sions top will snug fit orerthe bottom Note F2 folds will offset toward edge cardboard box topthis allows flaps fold outside box isnt pretty doubled flap area also greatly strengthens box will hold bigger weights piled top Next timefinishing box fixtures Models Overseas Indoor fliers active Scandinavian countries especially FAL events Two photos Sweden make clear indoor fliers same world overif didnt reveal photos came could guess Bud Tenny P0 Box 545 Richardson TX 75080 Safety/Preston Continued page 52 husband went see farmer took very wellconsidering farmer said Andrew father may have heard last freak accident So have Im sure some may have seen article originally appeared FM magazine wonder Burtons did hear farmer carried liability insurance also wonder Andrew finished changing mechanism presumably escapement single channel radio would guess could buy lot radios price quartette pregnant pedigree cows moral ofthis story Should requirement RC models equipped device currently available retard throttle upon loss transmitter signal doesnt generate some mail nothing will wind up safety column month publish story behind picture charred ukie also Doug Dahlke friend Dougs soldering wheel retainers onto model Mustang II using propane torch/iron model recently finished nitrate dope sitting balsa-dustcovered workbench modeler .tilted nozzle too far downward liquid propane ran forward causing burp hand airplane Hand quickly put out plane went up seconds Fortunately model burned up suppose model hanging over workbench some cans dope fuel sitting close Modelers work areas often surrounded combustible materials such balsa scrap box cleaning rags etc Take look around space imagine what might happen accidentally started fire extinguisher hand Perhaps its time perform long overdue annual cleanup Next month will discuss some other ways can destroy model maybe yourself fire Till think safety Before signing off month would like announce new award Senator Proxmire has Golden Fleece Laugh-In its Fickle Finger harmony logo calling Dissected Digit Award recipient will someone involved incident activity opinion best interests safety unsure just should receive dubious honor being first upon award bestowed turn page 23 April issue Model Aviation will see bottom left page photograph practice appears less prudent Although caption states model being cleaned presence pump equipped fuel can suggests de-fueling operation So either father captive playpen column writer sorry Ron unobservant Assistant Editor noble publisher its full gotcha Carl goes first award Dissected Digit May better future knows could next honor role Have safe month John Preston 7012 Elvira Court Falls Church V4 22042 Hills Are Alive/Groves Continued page 59 years old went war exper ience changed Western Front contest models military aircraft participating nations 1914-1918 war Because Hill Country grounds ideally suited dicey squirrelly planes WWI first Western Front contest held nine years ago Since has become perhaps longest-running June 1980 115 QUARTER SCALE 3 OT GIANT SCALE SPANDAU & VICKERS PLASTIC GUN KITS STANDARD PILOT COMPLETE WITH GOGGLES GNOME ROTARY ENGINE CYLINDERS VINTAGE GOLDEN AGE & BALLOON TIRE WHEELS w 3303 IN" SEND 5O FOR COMPLETE CATALOG MA 181 PAWNEE STREET SAN MARCOS CA 9 NEW BY POPULAR DEMAND