Control Line: Scale

Control Line. Scale Mike Gretz WHEN Sam Abdow Fall River Massa chusetts says flies jet scale models hes just blowin hot airbut models sure see Sam builds CL Scale replicas historic jet aircraft prefers power real jet engines case bur ied fuselage sleek Consoli dated Vultee XF-92A Delta Jet firebreathing powerplant called Dyna Jet Im going assume based AMA growth figures over last 10 years readers completely unaware age-old Dyna Jet engine pulse jets general probably may have heard seen jet model action couldnt tell much about fact make enough noise wake dead Im certainly authority pulse jets Ive never used way couple recently answered inquiries learned few basic facts about Dyna-Jet may find interest ing Dyna-Jet brand name true miniature jet engine has man ufactured over 25 years Citi zen-Ship Division Curtiss Dyan-Products Corp P0 Box 297 Westfield IN 46074 46074 still production today can bought direct fac tory $85 cash-with-order C0D basis Dyna-Jet solidfuel rocket type engine ducted fan way ex perimenters going try out CL Scale model true jet engine operating pulse resonant jet cycle like German WW II V-l Buzz Bomb modeling pulse jets can commonly seen AMA CL Jet Speed event Dyna-Jet engine approximately 21 inches length 2 inches dia meter its widest point cannot throttle controlled Weighing just 16 ounces will develop about 4 pounds thrust using unleaded regular gasoline fuel Quoting manufacturers instruc tion book Since cannot contain its cubic capacity air given moment Dyna-Jet cannot explode gasoline alone used fuel under pressure via tire pump supplied through blow pipe metered charge gasoline drawn fuel tank through Continued page 102 44 Model Aviation 1948 Colsolidated Vultee XF-92A research interceptor pioneered world trend delta wing aircraft Sam Abdows beautiful scale replica powered Dyna-Jet engine whQ have asked source given text Air Trails plans Cal Smith Frank Lashek Fairchild PT-19A has always popular scale subject because its classic lines generous wing area Author Mike Gretz wife Doris prepare launch Sport Scale win ning version 1978 Nationals Senior winner Paula uauer put good show Nats flying Gee Bea R-1 Supersport ster through several aerobatic maneuvers An original spans 54 inches has ST 35 power slogans taught us Dental School Dee B Mathews 506 S Walnut Greensburg KS 67054 Taming Autogiro/Kuhnle continued page 38 located slightly forward rotor force resulting nose-down pitching moment counterbalanced setting stabilizer pushed tail down same force arrangement used fixed wing planes except rotor force replaces combined lift-drag force wing good wing has relatively little drag lift-drag resultant almost vertical CG appears almost directly below wings center lift churning rotor blades create large amounts drag rotor force inclined relatively large angle respect vertical addition rotor usually located much higher above CG wing Because two factors though CG located slightly forward rotor force CG will located relatively large distance front rotors center giv ing erroneous impression center lift forward rotors cen ter proper location CG autogiro determined flight testing about three inches forward center rotor held loosely rotor hub fuselage hangs nose down angle about 20 degrees horizontal rotor disc tips back about 18 degrees thus confirming CG should lie slightly forward line drawn through center rotor perpen dicular plane blade tips rotate autogiros forward speed causes rotor disc tilt backward respect rotor shaft rotor disc also tilts sideways high retreating blade side due interaction between ward speed coning angle blades rotor force tilted side ways tending roll autogiro away retreating blade side rotor autogiro turns clockwise seen above side tilt rotor disc tries roll giro left can counteracted devon trim found satisfactory tilt top rotor shaft about three degrees retreating blade side right side Before building autogiro searched through large collection model maga zines found little useful information However did find book Aero dynamics Helicopter Gessow Myers Frederick Ungar Publishing Co NY very helpful understanding rotor blade motion [When writing advertisers mention read about Model Aviation CL ScalelGretz continued page 44 metering jet through spray orifices metered charge mixed air resulting combustible mix ture fuel air under pressure opens valve passes com bustion chamber fired spark plug receives its initial electric impulse external spark coil pressure resulting combustion closes valve sets up pressure wave tail pipe engine Once initial charge has inducted fired above opera tion automatic No further external forced air supply spark required pressure wave set up exhaust pipe firing initial charge cyclical nature first becomes negative pressure drawing another tered charge gasoline air through valve combustion chamber next becomes positive pressure closing valve firing new charge air hot gasses re maining previous combustion process repeated automatically rate 220-240 times per second long gasoline air supplied Well let Sam finish story unique brand CL Scale flying XF-92A weighs 6 lbs complete flies approximately 21 laps speed 85-90 mph built model 1974 using old set plans Air Trails magazine 1954 scale 1 inch foot has wingspan 31 inches 44 inches length Its built crutch using plywood formers bal sa planking Its finished Aero-Gloss white Air Force markings model lined internally layer asbestos paper two layers heavy-duty aluminum Reynolds Wrap foil using water-glass adhesive Around Dyna-Jet aluminum shroud 020 thick e between Dyna-Jet shroud approximately 1/2 between shroud insulation keep model catching fire Waterglass adhesive will burn As letter model has over 100 flights no problems need pit crew three people start jet holds model presses button spark coil operates air pump stay handle always airborne within two minutes ship lands open hatch pump air around Dyna-Jet cool down have building scale jets since 1954 1 flew XF-92A demo Aerolympics Scale WC 1974 Lakehurst New Jersey April 1978 1 flew model RC CL show Teterboro Airport Jay Gerber AMA HQ took film se quence jet hope will new all-scale film making needs information assistance 102 Model Aviation new CLASSIC kit prom FLYII LAKES Trainer 40 span 0925 power 4 channeLs nc $3495 complete catalog See dealer NOW No107 Fairchild 22 48 span 0915 power 3 channeLs nc $2995 FLYLINE MODELS INC 2020 DORR AVENUE B 2 FAIRFAX VIRGINIA 22031703 5732030 OUR AIM IS TO KEEP SPORT FLYING SPECIALIZING IN OT FF KITS AND ENGINES FOR THE COMPETITOR WE HAVE THE HOT EQUIPMENT s Enterprises PLANES1356 Ervin Road BOATSPO Box 227 CARSPangles Center TRAINSVan Wert OH 45896 4 Joe Guylas 4191 238-2625 WE BUY OR TRADE OLD ENGINES AND KITS UItie. Tine Filter System No single filter can equal double filtration performance Sullivan Crap Trap Thats because use two separate filters finer other Larger particles trapped out way corners front filter smaller particles fall similar trap rear filter see-thru Teflon barrel enables know sure filters clean after back flush Never trust valuable model enclosed single filter again Between tank engine insist Crap Trap CT-i .it s $115 Actually less ordinary single filter Between fuel container tank insist Crap Trap CT-P .it s $125 Includes larger fittings need use can trust Matty Sullivan always little things mean much us modelers Have discovered super Sulli-cone fuel tubing yet something else fIdUu~fr PRODUCTS N C 535 OAVISVILLE ROAD OW GROVE PA 19090 215 659-3900 scale control line jets could contact mail Sam Abdow 682 Eastern Ave Fall River MA 02723 Drowning Sorrows Im sure exactly one Murphys Laws must during construction before finishing new scale model will receive numerous unpretty little dents dings bare balsa wood Pencils screwdrivers falling out shirt pockets slipping metal straight edges table corners etc seem have knack messing up pretty work can call hangar rash Ill call aggravation Luckily little trick can some times ease pain dent too huge thin trailing edge balsa actually displaced pushed little water will often re store wood its original shape Ap ply healthy portion water directly dentdont wet down entire area youll deserve warp will undoubtedly get few hours later after water has evaporated balsa has puffed back up shape use some very fine sandpaper finish off surface Dont expect major mi racles try next time find small dent Its amazing couple months ago said some thing about Nats WC magazine cov erage its relevance modelers werent recent letter Nats competitor Jeff Perez wrote something interesting about thoughts Im sure competition ori ented modelers can relate Jeffs ex periences Before started flying Nats would dwell over Nats coverage magazines hours still magic comes up pages inspiring motivation gave inspira tion want get out become another Stott Gretz Platt Remem ber Lake Charles told wanted whip Stott because hottest thing wheels back got started Well see Thats what Nats coverage does Nationals magic Everything about Nats magic always will believe now competitors inspired whether realize was too Jeff big boys few years ago names like Keith Burnstine Harney Violett Its exciting think guys out right now planning knock us offin friendly way hope Thats what makes competition funwin lose Mike Grerz Box 162 Montezuma IA S0171 IWhen writing advertisers mention read about Model Aviation CL Aerobatics/Paul continued page 45 changing fuel head ST 46 has says Al new airplanes especially ones built Maxs Al making use adjustable height engine blocks approximately / aluminum will allow him infinitely adjust engine height tank seems critical Maxs Getting back crankshaft Max 45 Al pointed out following engines have crankshaft bear ing journal 15 mm Como 40 ST 45 Max 40 Max 45 HP 40 ST 46 has 12 mm journal So what Well what driving large crankshaft diameters allow greater crankshaft fuel passage allows fuel go combustion chamber supposed mean power Bill Werwage also agreed same point talked him back November about new Max engines So what does mean Joe Bellcrank means want try raw power can try Max 45 try 13-6 prop 5- 10-percent fuel wont have mortgage home machine shop can prob ably learn live speeding up plane round maneuvers learn enjoy pull power during March1979103 Does So Much More. Yet Actually Costs Less