• GUNSMOKE ACTION It’s A Scale Masters Qualifier
• AUVSI DRONE PRIZE
Show Us What You Can Do!
• ENGINE FUEL TANKS
How to Make Trouble-Free Fuel Systems.
• AEROBATICS XIV
How to Call It Like You’ll Fly It. RC-SF.COM
DOMINATE THE COMPETITION FLYING A BEAUTIFUL LASER 200 MONOPLANE!
DISCOVER RC SOARING IN THIS 1/4-SCALE GLIDER
USA & CANADA $6.49
RC Airplanes | Gliders | Helicopters MAY 2014
TABLE OF CONTENTS DEPARTMENTS
WHEN THE SMOKE SETTLED, IT WAS A SCALE MASTERS’ QUALIFIER EVENT.
PG 24
10 LEADING EDGE 12 HOT PRODUCTS 96 ADS’ INDEX 97 MYSTERY PLANE EVENT
24 30
GUNSMOKE 2014 IT’S THE ARIZONA MODELERS’ SCALE MASTERS’ QUALIFIER. By Tom Wolf
NAB 2014 WE TAKE YOU INSIDE NAB TO SEE MULTIROTORS. By Pete Hickerson
BUILD
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HOW TO OR 50 COWL 54 HATCH LATCH SEE HOW TO MAKE YOUR MODELS’ COWLS AND HATCHES SECURE IN FLIGHT. By Tom Wolf
HALL’S SPRINGFIELD BULLDOG
LEARN WHY THE CALLER MUST CALL YOUR ROUTINE WELL, AND LIKE YOU’LL FLY IT. By Daniel Holman
DANIEL EXPLAINS WHY A TRAINED CALLER IS INTEGRAL TO THE SUCCESS OF YOUR COMPETITION FLIGHTS.
PG 54
A 1932 CLEVELAND AIR RACER IS RECREATED. By Rob Caso
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AEROBATICS PART 14
SUPER SPORTSTER 60 LEARN HOW TO DO THE WOOD WORK ON THIS CLASSIC, LITTLE SPORTSTER. By Jeff Troy
THIS BUILLDOG HAS ONE UGLY MUG YOU WILL LOVE!
PG 36 6
RC SPORT FLYER . MAY 2014
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MAY 2014
3-VIEW
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DE HAVILLAND TIGER MOTH TAKE A GOOD, LONG LOOK AT THIS 1930S BIPLANE DRAWING TO SEE WHY IT MAY BE YOUR NEXT DESIGN. By Hans-Jürgen Fischer
COLUMN
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ENGINE FUEL TANKS ONE OF THE MASTERS SHOWS YOU HOW TO MAKE FUEL SYSTEMS. By Pete Bergstrom
PG 62
ELETRIC MOTOR POWER 8
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SEE HOW SYSTEM CURRENT IS AFFECTED BY MOTOR LOADING. By Andrew Gibbs
AUVSI DRONE PRIZE DISCOVER HOW TO WIN SOME MONEY DESIGNING A USEFUL DRONE . By Lucidity
REVIEWS
80 AIRBORNE’S 88 HALL CHEROKEE WE GIVE YOU AN INSIDE LOOK AT THIS 1/4-SCALE 1930s “WOODY” GLIDER DESIGN. By Gene Cope
AEROWORKS LASER 200 ARF THIS SCALE MONOPLANE IS DESTINED TO PUT YOU AHEAD OF THE COMPETITION. By Wil Byers
WE REVIEW AIRBORNE MODELS’ HALL CHEROKEE II 1/4-SCALE GLIDER TO SEE HOW IT PERFORMS ON THE SLOPE AND FOR AEROTOWING.
PG 80
PG 88
LIZ JACKSON, POSES WITH AEROWORKS’ BEAUTIFUL 1/4-SCALE LASER 200 30cc ARF. facebook.com/rcsportflyer
RC-SF.COM
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HOT PRODUCTS BVM CLEVIS PLIERS
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ow rigging the metal clevis linkages on your model is made easier with the BVM Clevis Pliers. Their precision pliers are kinder to your fingers and help avoid overstressing metal clevises. They are designed to work well with all 2-56 and 4-40 metal clevises such as those by Sullivan, DuBro and Great Planes manufacturers. These new modeling pliers are made to make rigging control systems easier, faster, less frustrating and to save wear and tear on your fingers. Access into hard-to-reach areas is now much easier and you don’t need a screw driver that can slip and
puncture the adjacent surface. Price $32.95
(PA-SR-0060)
Distributor BVM JETS 3481 State Road 419 WinterSprings, FL 32708 Phone: (407)327-6333 bvmjets.com tel 407-327-6333
COMMON SENSE RC LECTRON PRO 7.4 VOLT LIPO
C
heck out Common Sense RC’s new LiPo pack, with EC2 connector, that has been designed specifically for the HobbyZone Delta Ray and Firebird Stratos. It has been rated and tested at 33.75 amps continuous discharge, with 67.5-amp bursts. This pack will power your model to the stratos. Price
Specifications Type Length Width Height Weight Voltage Capacity Rating Connector
$18.95 (2S1350-25-L)
LiPo 63.5 mm 34.9 mm 15 mm 73 g 7.4 1350 mAh 25C EC2
Distributor Common Sense RC P.O. Box 3546 Chatsworth, CA 91313 Phone: 866-405-8811 Commonsenserc.com
ESPRIT SERVO WIRE HARNESSES
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ow you can build custom servo harnesses using Esprit’s dual threelead servo wire. It is sold with Multiplex six-pin connectors installed. They make for safe and professional servo extension installations. The fuselage’s (male) harness comes with JR® connectors installed and 6- or 10-in. (150- or 250-mm) three-lead servo wire. The wing’s (female) harnesses come in 26/8-, 31.5/8- or 47/20-in. (650/200-, 800/200-, 1200/500-mm) lengths. They
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RC SPORT FLYER . MAY 2014
are all made of threelead, twisted silicone type wire. These leads are perfect for sailplane wing configurations that are removable. You can connect two aileron servos, or flap and aileron servos in each wing. Price
$12 – $15
Distributor Esprit Model 1240 Clearmont St. NE #12 Palm Bay, FL, 32905, USA Phone: 321-729-4287 espritmodel.com twitter.com/rcsportflyer
GOLDEN SKIES DLA 128-CC QUAD-BOXER ENGINE
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olden Skies R/C Aircraft, Inc., the USA distributor and service center for DLA engines, is announcing their new DLA 128cc Quad-Boxer engine. It is an evolution design that comes out of the 32/64-cc cylinders. The DLA 128 is CNC machined from 7075 aircraft grade aluminum. Golden Skie says, “The scale warbird builder will value the “pitch” weight in the engine, not in dead weight. The sound is purely awesome. Producing ~13 hp @ ~8,000 rpm and swinging up to a 29 x 10 prop, it runs so smooth that it barely shakes a glass of water. With a static thrust >61 pounds, a pilot can depend upon its performance.” The engine uses dual Walbro© carburetors and dual ignitions. All the necessary engine components are included in the shipping box. Price
Distributor GOLDEN SKIES R/C AIRCRAFT 30882 Rivera Place Laguna Niguel, CA 92677 Phone: 949-378-5998 goldenskiesrc.com
Specifications Cylinders Carburetors Displacement Static Thrust Weight
$1399
Four Two 128 cc >61 lb ~120 oz
DLE 85-CC SINGLE-SINGLE POWER Distributor Great Planes P.O. Box 9021 Champaign, IL 61821 Phone: 800-637-7660 greatplanes.com
JETI MOMENTARY SWITCH
E
sprit Model has just announce that the new Jeti momentary pushbutton switch for both the DC and DS transmitters has come into stock. This switch offers even more ways to customize your Jeti transmitter — not to mention it gives you many extra programming options as well. This is a good addition to any of the Jeti DC/DS transmitters.. Price $17.00
Distributor Esprit Model 1240 Clearmont St. NE #12 Palm Bay, FL, 32905, USA Phone: 321-729-4287 espritmodel.com facebook.com/rcsportflyer
V
ibration is a concern for most largescale, single-cylinder engines, but the DLE’s 85 keeps it in check with a vibrationdampening engine mount. The new 85 includes an extension on the exhaust that lessens the chances of having to modify the cowl, and it will flex or pops off during a hard landing, which helps protect the engine against shock. Giant-scale pilots will appreciate the DLE-85’s impressive power and performance. Features • Engine mount specially designed to dampen vibration • Exhaust extension aids in installation and protects the engine and muffler during a hard landing • Ignition module accepts voltages from 4.8 – 8.4 volts, and is wired for the DLE tachometer (DLEG5525) Price $549.99
(DLEF0085)
Specifications Displacement Bore Stroke Total Weight Output Propellers
84.88 cc (5.18 cu in) 2.047 in. (52 mm) 1.574 in. (40 mm) 5.09 lb (2.31 kg) 8.5 hp @ 7500 rpm 25 x 10, 26 x 9, 27 x 8
RC-SF.COM
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EVENT HOW TO
GUNSMOKE 2014
SCALE MASTERS QUALIFIER
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he Gunsmoke Scale Masters Qualifier has been the premier scale event for the Southwest region for over 20 years. It attracts contestants from as far away as Texas, Colorado, California and Oregon. This year there was a contestant from Massachusetts, which likely sets a Gunsmoke distance record. Gunsmoke is one of 20 to 25 Scale Masters Qualifiers held each year throughout the United States and Canada. The top finishers at each of the qualifiers are invited to participate in an annual US
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RC SPORT FLYER . MAY 2014
Scale Masters Championships, which is held in the Fall. Gunsmoke 2014 was held February 28 through March 2 at the Arizona Model Aviators home airfield, Superstition Air Park, in Mesa Arizona. As has been true for the last few years, it was organized and run by the One Eighth Air Force, an AMA sanctioned club specializing in scale modeling that is based in the greater Phoenix area. The One Eighth Air Force was founded in 1976, and currently has 130 members; 70 from Arizona and 60 from throughout the
BY Tom Wolf
rest of the country. Like the US Scale Masters, the One Eighth Air Force’s mission is to promote scale modeling and scale competition. In addition to the Gunsmoke event, they also host two scale fly-ins in the Phoenix area, one in the Fall and one in the Spring. The One Eighth Air Force also provides significant support to other scale events throughout the country, including the US Scale Masters Championships. Superstition Air Park is well suited for hosting large events such as this qualifier. It is located approximately twitter.com/rcsportflyer
Kevin Hopwood’s entered this excellent Supermarine Spitfire Mk IX. Kevin teamed up with Mike Hatfield (pilot) to enter in Team Scale. Every detail is present on this Spitfire, creating the illusion of this being a shrunk-down version of the full-size aircraft
The cockpit on Kevin Hopwood’s Supermarine Spitfire is an extremely well done rendition of the full-scale aircraft’s.
25 miles east of downtown Phoenix Arizona with lodging and restaurants nearby. The field features a 700-foot-long by 100-footwide paved runway, a very large permanent sunshade structure in the pit area with ample space for the assembly of aircraft, and spectator bleachers at either end of the pit area. In addition, electrical outlets are located in several places in the pit area, with the power being supplied by the Arizona Model Aviator’s generator. This year’s event was very facebook.com/rcsportflyer
well run, which has been typical of Gunsmoke over the years. The Contest Director was Austin Goodwin, and the Assistant CD was Mike Peck. Austin and Mike assembled an experienced crew of event workers, including static and flight judges, flight line workers, score keeper and runners for getting the score sheets from the judges to the score keeper in a timely manner. The result was a first-class
event that ran smoothly. The only hitch to an otherwise excellent event was the threatening weather. A major storm hit drought-stricken California starting Thursday night and continuing through the weekend. Locally, rain was forecasted for the Phoenix and Mesa area starting Friday evening and running through Saturday night. The threatening weather undoubtedly impacted the turnout for this year’s event, with RC-SF.COM
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EVENT HOW TO
NAB 2014 DRONES TAKE ON THE LAS VEGAS STRIP AT NAB
BY Pete Hickerson
T
he National Association of Broadcasters (NAB) convention is an annual event held in mid April in Las Vegas, Nevada at the Las Vegas Convention center. It is literally a technology and information Mecca for many in the broadcast industry. A yearly pilgrimage is considered
essential, just to keep up with changing equipment and software. This year nearly 100,000 attendees visited 1746 exhibitor booths. RC Sport Flyer attended NAB in 2014 because over the last few years exhibitors promoting manned helicopter services for film
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production have been overtaken by remote controlled (RC) multirotor helicopters. Filmmakers are turning to RC aircraft in large numbers, and for good reason. The average cost for manned helicopter video ranges from $9,000 to $20,000 or more for a full-day of shooting. Producers
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The DJI booth had high volume of traffic with interest in all models. The booth was positioned at a main entryway.
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DJI’s S1000 octacopter was getting short workouts as we all lusted after it, with retractable landing gear and 350˚ gimbal.
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The new Phantom Vision+ has the new 3axis gimbal. It made lasting impressions as people witnessed it up close.
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RC SPORT FLYER . MAY 2014
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4 5
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Yuneec displayed their new QX2 with in house designed architecture and support — shown with HD viewfinder built into the controller.
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This was a drone from Sweden with 20-lb weight capacity and up to one hour flight time depending on payload. It was big!
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It seemed like everywhere you looked there were drones and companies embracing this type of quadcopter technology.
have discovered they can purchase a multirotor machine for the same cost as a day of production with a manned helicopter — and they’ll own it for future shoots. DAY 1 The first day of the show, large crowds were gathered around booths like DJI. There, there were two flight areas cordoned off. When their new Phantom 2 Vision+ took to the air, the crowd moved in for a closer look. The Phantom 2 Vision+ has DJI’s camera fitted to it on a three-axis gimbal. The company promises, “It will shoot fully stabilized video from the sky, right out of the box.” For many consumers as well as small production companies, this is an attractive configuration. facebook.com/rcsportflyer
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ATI (Aerial Technology International) had one of the most amazing technologies I saw. They were sporting a hexacopter with twelve GoPro™ cameras for recording 360˚ video.
DJI Other DJI models offer promising features for professional broadcasters and larger production companies. Several new Spreading Wings S1000 models were on display, each equipped with a threeaxis gimbal. One model was shown with a Canon 5D Mark III attached, and another with the Blackmagic Pocket Cinema camera. Many of these top of the line models featured exciting improvements. For example a slip-ring gimbal that turns 360 degrees without unruly cables to tangle. It was well received by attendees. Retractable landing gear moves it out of the shooting area. Then too, a new first person view (FPV) system named Lightbridge was shown. This system beams
video back to the RC controller up to two miles away. What makes it special is that both the control signal and the video are transmitted via a common 2.4-GHz signal. The S1000 octocopter also sports folding rotor arms and a spark-proof power cord plug. Willis Chung, a flyer in the DJI booth stated the S1000 was so stable it could loose one rotor and still fly. YUNEEC After the fun at the DJI booth, we made our way around the convention site in search of more UAV companies and there were many. The next one visited was YUNEEC, a Chinese company with offices in Australia, Germany and Ontario, California. They were showing their QX2 quadcopter. The RC-SF.COM
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BUILD
The surprisingly sleek Bulldog is a crowd pleaser both in the air and on the ground. The sprung landing gear was a real design challenge for me.
HALL’S SPRINGFIELD BULLDOG 1932 CLEVELAND AIR RACER LIVES TO RACE AGAIN
O
f all the comments I receive on my Bulldog model, the two most common are: “I never saw one of those before” and “that thing will never fly.” It’s always quite a risk in terms of time, materials and effort designing models of obscure prototypes. There are usually few, if any, other existing models to glean design ideas from. Then there were probably some
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RC SPORT FLYER . MAY 2014
very good reasons in the first place why there were only a few or, in this case, a single full-scale example ever built. Plus, it’s hard to find photos and usually there are no diagrams. Sometimes modelairplaneland is a lonely place to be. Nevertheless, it’s kind of nice not to show up at the RC airfield (or at a contest) with the 32nd P-47 of the day and having a oneoff design that flies well has always
BY Robert J. Caso
been a personal modeling challenge for me. The Bulldog certainly meets these requirements, although I assure you there was quite a bit of trepidation during the course of the design and build as to whether this thing would be flyable. I built the model specifically for the Neat Fair Air Racing Society (NFARS) event, which was held in 2013. NFARS entries were required to twitter.com/rcsportflyer
be built within certain size parameters and must have been constructed as an original design or from a kit. The February, 2014 issue of RCSF has my article outlining this event and showcases the models of the very talented group of modelers that my friend, Thayer Syme, recruited.
I look a little tired here in this pre-NEAT Fair shot. It was because of all the late-nights’ working on the Bulldog getting it ready for the Fair.
PROTOTYPE Bob Hall’s gull-winged racer was built under contract for Marion Price Guggenheim of the New York family, well known for their support of all types of aeronautical activities. Mrs Guggenheim would later christen the new airplane the Bulldog, in honor of the famed Yale University mascot. The airplane was powered by a Pratt & Whitney R-1340 Wasp Jr engine, which developed 535 horsepower. With a wingspan of 26 feet and a fuselage length of 19 feet, the
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The powerful, fan equipped, OS Max motor is perched on the removable firewall. It is of the typical OS Max quality you’d expect.
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I could fill a book on how long it took me to modify, build and detail the 1/6-scale Williams Brothers Pratt and Whitney ninecylinder dummy engine.
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The dummy engine just slid within the modified Fiberglass Specialties cowling. A half inch was sliced from the cowl and then rejoined.
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This is a test fit of a defunct version of the removable firewall— six Allen screws hold it securely to blind nuts on the fuselage ring.
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BUILD
Basic construction, rough shaping and sanding was completed in previous installments. Here are the primary airframe components of my Great Planes Super Sportster 60.
SUPER SPORTSTER 60 HOW TO DO THE WOOD WORK
T
his installment has me measuring for the wing installation, mounting the stabilizer and vertical fin, and giving you a few shaping suggestions for the lower wing fairing blocks. The Super Sportster 60’s wing is held to the fuselage with four 1/4-20
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RC SPORT FLYER . MAY 2014
BY Jeff Troy
nylon bolts. Holes for these bolts must be drilled through the wing and into the plywood hold-down plates in the fuselage. It’s imperative for the wing to be perfectly aligned in the fuselage’s wing saddle. Here’s how I do it: Inside the fuselage, but visible twitter.com/rcsportflyer
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Mark the center of the fuselage to help prepare for aligning the wing in its saddle. You’ll want a good steel ruler for this measurement—one that does not bend.
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It’s a good idea to mark the estimated positions of the wing bolts so you don’t drill the holes through the balsa triangle strips or miss the plywood mounting plate altogether.
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You must center the wing in its saddle. I do it by lining up the pencil mark with the center of the wing-joiner rib as I’m showing in this photo. It is easy and quick to do when you use this timetested method.
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Four nylon bolts secure the wing to the fuselage. I drill only one 3/16-in. pilot hole to begin the mounting. Then I remove the bit from the drill, and insert it into the drilled hole, allowing the wing to pivot slightly while I measure. The three remaining holes can be drilled after the wing has been measured for its proper position in the wing saddle.
above the wing’s leading edge, make a pencil mark at the center of the bulkhead in front of the wing. Then make two more reference marks on the fuselage chin, right and left of the center mark and just slightly inboard of the triangle strips on either side of the plywood plates. The first mark will help you find the center of the wing, and the second two marks will show you the left-and-right positions of the wing-mounting holes. The final positions will be in line with those two marks, and approximately 1/2-in. behind the leading edge of the wing. Make similar right-andleft marks on the fuselage bottom behind the trailing edge of the wing. Place the wing in the saddle, and line up the center mark on the facebook.com/rcsportflyer
bulkhead with the center of the wing-joiner rib. You can use the eyeball method to center the trailing edge between the fuselage sides, and when the wing appears to be centered, drill a 3/16-in. hole in one of the two forward locations, down through the wing, into and through the plywood hold-down plate. It’s important only one hole is drilled now. Insert a length of 3/16-in. dowel, music wire, or the drill bit, into the hole, semi-securing the wing while allowing it to pivot slightly in the saddle while you measure for its exact position. There are several methods for measuring, but the one I rely on most is the dial-cord method. Dial cord is a non-stretch cord that was
used in many older, knob-style radios to mechanically move the tuner indicator across the face of the screen. You can find dial cord in better electronics parts houses, and a recent Google search brought it up on eBay, Amazon, and other sources under vintage radio dial cord. Alternately, any other type of line that does not stretch will work. Prepare the measuring line by tying one end around a T-pin, and folding a 1-in. strip of masking tape over the line at the opposite end. Use a thin marker to draw an arrow on both sides of the folded tape. Now stick the pin, dead center, into the bottom of the fuselage at the tail, and pull the taped end gently toward one of the wingtips. Most RC-SF.COM
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HOW TO
COWL OR HATCH FASTEN THEM SECURELY FOR FLIGHT
BY Tom Wolf
H
ave you been frustrated with engine cowls or access hatches coming loose because of engine-induced vibration? For years I installed cowls on my airplanes with machine screws that were threaded into conventional blind nuts (T-nuts). Often these screws came loose during flight. I tried using thread locking compound on the screws with some success, but I found it to be inconvenient when the cowl had to be removed at the airfield to make an adjustment to the engine. Most thread locking compounds require several hours to cure, which is impractical if one wants to fly immediately after reassembling the hardware.
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An access hatch or an engine cowl can be securely attached by anchoring 2-56 flat head screws into short sections of the inner tube of a nylon pushrod. RC SPORT FLYER . MAY 2014
USE FOR NYLON PUSHRODS What do nylon pushrods have to do with the locking hatches and cowls in place? As it turns out, a short piece of the inner tube of a nylon pushrod is a good vibrationresistant alternative to a blind nut for applications such as cowl or access twitter.com/rcsportflyer
hatch attachments. Somewhere along the way I stumbled onto this idea and I’ve been using it for many years for my models’ cowl and access hatch attachments. Since then, I have had no problems with screws backing out. So instead of throwing those scrap nylon pushrods away, I now save them for this use. Please note: This mounting technique is not suitable for situations where there is a significant tension load being applied to the screw. An example of this type of loading would be the attachment screws holding a landing gear assembly onto the bottom of the aircraft’s fuselage. In those situations, the best approach is to use a blind nut, or a conventional nut and washer for the attachment. The nylon pushrod concept is quite simple. The inner tube of a standard nylon pushrod accepts a 2-56 screw very nicely, and it
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To improve adhesion, roughen the outer surface of the nylon tube with sandpaper.
does so with a significant amount of thread locking. Short sections (approximately 0.50-in. long) of nylon tubing are inserted into holes in the aircraft structure and then glued in place with thin cyanoacrylate (CA) adhesive — photo 1. The cowl or hatch attachment screws are then screwed into these nylon inserts. If a 2-56 attachment screw is too small for the application,
use the inner tube from a heavy-duty nylon pushrod (i.e., Sullivan S517), which accepts a 4-40 screw. STEP BY STEP Step 1 Tape the cowl or hatch in place and, at each desired fastener location, match drill through the hatch or cowl, and the support structure, behind with a drill that
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You’ll want to mark the location of the holes in the support structure. Then you’ll drill the holes in the wood. Insert the nylon tube into holes drilled into the hatch or cowl support structure.
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After the nylon tube is inserted approximately 0.5 inch, thin CA adhesive is wicked into the joint.
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Use a hobby knife to trim the nylon tube flush with the hatch or cowl mating surface. RC-SF.COM
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HOW TO
AEROBATICS PART 14 THEY MUST CALL IT LIKE YOU WILL FLY IT BY Daniel Holman This photo shows me performing a high speed, slow-rolling circle at a local event with my Extreme Flight 104-in. wingspan Extra 300.
CALLING
S
pring is but a few weeks away! That means the competition season for aerobatics is right around the corner. In this issue, I will pick up where we left off in my discussion of how to get involved in International Miniature Aerobatic Club (IMAC) competition. I’ll continue with the elements of precision aerobatic competition flying. CALLING Formerly, I explained the necessity of having a good caller working with you. Now let me detail how to call precision aerobatic maneuvers. In the following photo, you will see two maneuvers taken from my Unlimited, Known sequence. I encourage you to envision these maneuvers in your mind. Then follow the diagram as I call them. Note that the first maneuver is on the right side, and the second is on the left. REVERSE SHARK-TOOTH From inverted, push to vertical; one and one-quarter negative snaps; opposite quarter roll. Pull five-eights loop to a forty-five down. Two of eight; opposite three quarter snap to inverted. Pull to exit upright; half roll to inverted. HAMMERHEAD From inverted, push to vertical and perform two negative snap rolls on the up-line. Hammer into the
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RC SPORT FLYER . MAY 2014
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wind — caller should check wind and remind the pilot of the proper hammer-direction. Two consecutive rolls on the downline; push to exit inverted. KNOWNS AND UNKNOWNS The final details of IMAC competition I need to explain deal with the two different types of flights the competitors perform. The two different types of sequences that are flown are called the Known, and the Unknown. As you might have already guessed, the Known flight is provided to the pilots before they compete so they can practice it. Every year, the Known sequences for each class — Basic through Unlimited — are released before the IMAC competition season starts. These Known sequences are used for all IMAC sanctioned contests during that year. Although mixed up and modified, the maneuvers for each class are very similar in difficulty year to year. While I highly recommend competitors memorize the Known sequences, having your caller read the Aresti sequences through the flight is still very important and should avoid lapses in memory.
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Next is the Unknown flight. Before delving into it, I need to make the point that the Basic class does not have an Unknown. In the Sportsman through Unlimited classes the competitors should arrive at the contest with their Known sequences firmly engrained in their minds and perfected. The Unknown sequences on the other hand, will not be seen until the pilot arrives at the contest; and, this is often not until the end of the first day. The Known sequence for each class is made up of maneuvers with similar difficulty levels as those in the Known
Jerry Smith captured pilots at an IMAC competition near Atlanta, Georgia. Competitions such as this bring in lots of pilots, neat airplanes and are a true joy to attend.
Here, I am performing a low inverted flat-turn. If you try this with a tail-heavy airplane, in most cases you will have to add a small amount of up-elevator with the rudder. A slightly nose-heavy CG is best!
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3-VIEW
DE HAVILLAND DH.82 TIGER MOTH IT’S A MOTH YOU LOVE TO SEE FLYING
T
he de Havilland DH.82 Tiger Moth is a 1930s biplane designed by Geoffrey de Havilland. It was operated by the Royal Air Force (RAF) and others as a primary trainer. The Tiger Moth remained in service with the RAF until being replaced by the de Havilland Chipmunk in 1952, when many of the surplus aircraft entered civil operation. Many other nations used the Tiger Moth in both military and civil applications, and it remains in widespread use as a recreational aircraft in many countries. It is still occasionally used as a primary training aircraft, especially for pilots wanting to gain flight experience before moving on to other tailwheel aircraft, even though most Tiger Moths have a tail skid rather than a tail wheel. Many Tiger Moth biplanes are now used by flight operations as a way of offering flight lessons and for sightseeing rides. The Tiger Moths that are privately owned are primarily flown for air shows and for recreation. Note there is a de Havilland Tiger Moth club, which was founded
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RC SPORT FLYER . MAY 2014
SPECIFICATIONS
BY Hans-Jürgen Fischer Crew : two, student & instructor Length : 23 ft 11 in. (7.34 m) Wingspan : 29 ft 4 in. (8.94 m) Height : 8 ft 9 in. (2.68 m) Wing area : 239 ft² (22.2 m²) Empty weight : 1,115 lb (506 kg) Loaded weight : 1,825 lb (828 kg) Powerplant : de Havilland Gipsy Major, inverted 4-cylinder inline, 130 hp (100 kW) Maximum speed : 109 mph at 1,000 ft (97 kts, 175 km/h at 300 m) Cruise speed : 67 mph (59 kts) Range : 302 miles (250 NM, 486 km) Service ceiling : 13,600 ft (4,145 m) Rate of climb : 673 ft/min (205 m/min)
1975. It is a well organized owners’ association to provide support and information. The de Havilland Moth Club welcomes anyone with an interest in aeroplanes designed and built by the de Havilland Aircraft Company at Stag Lane and Hatfield between the wars. FMI: dhmothclub. co.uk.
Role Trainer Manufacturer de Havilland Aircraft Company Designer Geoffrey de Havilland First flight October 26, 1931 Produced 1931–1944 Number built 8,868 Retired 1959 Used By Royal Air Force Royal Canadian Air Force Royal Australian Air Force Royal New Zealand Air Force
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THE DE HAVILLAND SCHOOL OF FLYING
Fahrtmesser am linken vorderen Stiel
De Havilland 0
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DH. 82A Tiger Moth Zeichnung © by H.-J.FISCHER 2012
COLUMN HOW TO
ENGINE FUEL TANKS
MAKING TROUBLE-FREE FUEL SYSTEMS
BY Pete Bergstrom
W
e’ve all endured, or seen the results of, a poor or haphazard fuel tank installation in an RC aircraft. They make for reliability problems or worse. Troubles occur when the engine can’t draw fuel, or it runs fine on the ground but when the airplane gets 20 feet in the air the engine quits—in the worst place and time, which can result in an off-field landing or crash! Often the modeler is quick
to blame the engine design and manufacture for the engine’s poor running. The reality is the engine’s problems are closer to home, with the construction of and installation of the fuel system. So, this month I want to examine a few of the common fuel system problems. Then I’ll talk about ways to solve them. CLEANLINESS Cleanliness is next to
righteousness when it comes to fuel systems. I’ll say so a couple of times in this article because dirt and debris are the number one cause of RC aircraft fuel system problems. Use fuel filters — multiples! They are inexpensive insurance against problems. Use a filter in the bottom of your fuel jug, and again in line between the fuel jug and the fuel tank. For the onboard fuel, I prefer to use a filtered fuel pickup (clunk) in the tank and then no filter between the tank and the carburetor. You can add an inline fuel filter between the tank and the carburetor; however, I’ll explain my objection to doing so later. CONSISTENT What does a tank need to do? In its simplest form the tank needs
There are a couple of different types of stopper material — one for glow fuel and one for gasoline.
You’ll also need to select the proper fuel tubing for the fuel type: silicone, Tygon® and Viton®.
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to deliver a reliable and consistent amount of fuel to the engine at all times, regardless of the aircraft’s flight attitude. Our common solution to the consistent fuel delivery for the engine is to install a flexible fuel line with a weighted pickup, or clunk. The clunk is attached to the line’s end that reaches to the rear of the fuel tank. This in theory allows the fuel’s clunk to be in the same place as the fuel while the aircraft is in flight. Gravity affects the fuel and the clunk equally. So as the airplanes rolls left or right, or pitches up and down, the clunk follows the fuel and is always submerged.
This shows three clunk styles: felt filter (EVOA112), sintered (DUB161) and standard. Also shown are two fuel filters: HAN143 Pro Filter on left and EVOA111 on right.
This is typically how you’ll get a standard tank assembly as it comes out of the package, and with its accessories.
VENT / FILL The tank needs to have some sort of a venting system to allow air in to replace the fuel used by the engine. Also, the tank must be easy to fill. Typically the tank’s vent is a hard line (copper or brass). It is bent so its inside end is at the top of the tank when the airplane is sitting on its wheels. There are a number of ways to get fuel in the tank: 1) Remove the fuel line from the carburetor and pump the fuel into the tank. 2) Use a T-fitting, with a capped third line into the fuel line between the tank and the carburetor. 3) My favorite is to add a third line to the tank that is dedicated to adding or removing fuel. PROBLEMS Fuel system problems can creep into the aircraft’s operation during construction, aircraft maintenance or normal use. Here are some tips for preventing fuel system problems: • During construction, remember cleanliness. Make sure you rinse out the fuel tank with isopropyl alcohol prior to starting construction. Although the typical milky white interior of a new fuel tanks appear to be clean, I can’t tell you how many times manufacturing debris, in the form of small nylon bits the same color as the tank, have been found in my models’ tanks. Make cleaning a normal part of your aircrafts’ facebook.com/rcsportflyer
Here you see how I build a three-line tank setup. The next step will be to install it in the tank and tighten the stopper.
construction routine. • Always use new, clean fuel tubing. Trying to save money by reusing old tubing that may be dirty and/ or split does lead to fuel supply headaches. • An improperly tightened stopper/ cap assembly will either leak fuel or allow air to enter where
and when you don’t want. You should not over-tighten the cap either because you can split the fuel tank. This problem is not as common as it used to be because most companies now provide fuel tank caps that extend completely over the stopper, and secure themselves around the stopper’s RC-SF.COM
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COLUMN HOW TO
The purposeful, pugnacious looks of the A-7 Corsair have always appealed to me. The model has all the character of the full scale.
E-POWER 8
CURRENT REVOLVES AROUND MOTOR LOADING
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his month I’m starting my column with a model built by Neil Jarvis. Then I continue my discussion of electric power systems. A-7 CORSAIR
To date, I’ve only shown you propeller-driven aircraft. So, this month I’ll detail an electric-powered ducted fan (EDF) model. The model is a Jet Hangar Hobbies’ kit of the A-7 Corsair. It was built by British
The Corsair’s chin intake provides plenty of intake air for the model’s Stumax ducted fan.
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BY Andrew Gibbs
modeler expert Neil Jarvis. Neil bought the A-7 as a used airplane. He subsequently reequipped it to power specifications of his choice. With a wingspan of 47 inches, it
The ducting on this high performance model starts at the fan’s intake. This simplifies the installation but reduces thrust. twitter.com/rcsportflyer
This photo shows the flap and aileron torque rods. These have slightly different axis. Note the pink safety keepers on the clevises.
Two of the four wing and flap servos can be seen here. Neil has wired all the wing’s servos to a single multi-pin plug.
The wings of this Corsair support its 14-pound weight easily, especially in view of the surprisingly high wing loading!
is a relatively large and impressive 1/10-scale model. While a 47-inch wingspan may not sound like a large model, the fuselage of the model is 57 inches in length. The bulk of this model may be appreciated by way of the photographs. Further, when I examined it, the model certainly did not feel small! POWER ANALYSIS With propeller driven models, the output power can be adjusted by changing the propeller’s pitch, diameter or both. Consequently, you can make adjustments to the amount of power delivered by a motor system quite easily—within reason of course. As such, you can tune a facebook.com/rcsportflyer
model’s power system to the needs of the model. In contrast, with EDF models, the complete power system must be carefully chosen, since the motor and fan (impeller) cannot easily or cheaply be changed. About the only thing that can be done to increase or decrease the motor’s power is to increase/decrease the number of cells in the battery pack. However, given that most EDF models can use all the power possible, it’s common to install a battery with the maximum cell count for the power system that is running the ducted fan unit. With any jet-powered model, it’s important to make sure the EDF
This view of the fuselage interior shows the position of the 100-amp ESC, which is the finned black object. RC-SF.COM
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COLUMN HOW TO
AUVSI DRONE PRIZE SHOW US WHAT YOU CAN DO!
While the FAA fiddles and a multi-billion dollar industry-inwaiting burns (with anticipation), hobbyists have a unique opportunity to shape the future — and win awesome prizes.
BY Patrick Sherman
DJI’s new S1000 octocopter is designed to carry camera, avionics, GPS system and transmitter receiver for the video downlink. It will fly about 20 minutes.
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ike an 11-year-old boy stuck in the back seat on a long road trip after the batteries have gone dead on his Nintendo DS, the domestic drone industry just wants the answer to a single, simple question: “Are we there yet?” The reason is clear: the Association of Unmanned Vehicle Systems International (AUVSI) estimates that within three years of their approval, the market for nonmilitary drones in the United States will top $13 billion per year — rising to $80 billion per year by 2025, which translates into about 100,000 good paying jobs. However, like the weary parent behind the wheel, the Federal Aviation Administration (FAA) keeps giving the same answer: “No.” That answer won’t be changing for at least the next 18 months, and very likely
This is another look at the S1000, but without all the hardware installed. It was recently introduced by DJI as an upgrade to their S800 camera platform.
for a year or two beyond. As a result, it won’t be the titans of the aerospace industry who will prove how Small Unmanned Aircraft Systems (sUAS, i.e., “drones”) can benefit society, because they are legally prohibited from flying except under the most rarified circumstances. Instead, providence has entrusted that heady responsibility to an elite group of amateurs, enthusiasts and hackers — one of whom, I know for a fact, is reading this month’s issue of RC Sport Flyer at this very moment. ALL ABOARD! The big boys are grounded and, until they are cleared for takeoff, the hobbyists rule the skies. It’s up to you — yes, you — to show what this technology can do, and the field is wide open for all sorts of new
DJI’s Phantom II Vision is an affordable solution to getting great video from a quadcopter. You can equipped it with a three-axis camera gimbal too.
Here is another DJI product, their Flamewheel F550. You can add a landing gear set and a camera to this model as well. The DJI machines are sold by AtlantaHobby.com. facebook.com/rcsportflyer
ideas. Honestly, I don’t think that anyone has even thought up the best applications for these systems yet. If you burst in to an Advanced Research Projects Agency computer science lab in 1975 and demanded to know what ARPANET — known today as “the Internet” — would be used for in 2014, I’m not sure what those early pioneers would have told you. However, I am certain their answer would not have included smart phones, Twitter, Google, Amazon or YouTube. Yet, these unimagined applications are transforming the economic and political landscape of our world in ways that would have been impossible without them. If someone burst in to my office right now and demanded to know what drones will be used for in 2053, the only answer I could offer with
Probably DJI most affordable entry into the multi-rotor market is their Flamewheel F450. When equipped with the NAZA control system it works well as a camera platform too. RC-SF.COM
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REVIEW
HALL CHER Your model comes packed and shipped in one of the best boxing jobs we’ve seen. The wing bag is the first thing you see when the box is opened. The model’s parts are bagged and taped to make them secure against damage.
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Once all the parts were removed and laid out, it became evident that the Hall Cherokee almost-ready-to-fly glider is one of the best kits I’ve seen. You get everything you need with the exception of the radio gear. twitter.com/rcsportflyer
Here the Hall Cherokee is captured silhouetted against the laterafternoon sun while slope soaring late in the day at Eagle Butte in Southeast Washington State. The model was flown in a wind that was blowing about 14 mph.
OKEE II ARF
AIRBORNE MODELS GIVES NEW LIFE TO A CLASSIC HOMEBUILT GLIDER BY Gene Cope
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irborne Models has just released a new quarter-scale Hall Cherokee II ARF glider. It makes for a very affordable, scale “woody” glider that is perfect for pilots that are into aerotowing and/ or slope soaring. The glider is based on David Smith’s drawings, which he created in CAD from the full-scale Hall Cherokee II plans. This version was modified from that of the fullscale’s construction, but maintains its scale outline and overall appearance. It an appealing glider on the ground and in the air. The Cherokee II was a Stan Hall design. As a full-scale glider it was a homebuilt machine. The Hall facebook.com/rcsportflyer
Cherokee was built from plans, sold by Mr Hall, that originally cost $35. The materials to build a Hall Cherokee in those days cost all of $500. The structure was wood, with metal fittings, and it was covered in fabric. It is interesting in that Stan Hall stopped offering plans for the glider March 15, 1961. As he said when he stopped offering the plans, “The production of parts, kits or complete sailplane is not authorized anywhere in the world, unless carried on in the same spirit in which I developed the design — as a hobby, without profit.” Stan nailed his design for the Hall Cherokee II and for his love of the soaring hobby.
I think Airborne Models has nailed it with their new glider ARF offering. AIRBORNE MODELS ARF The Cherokee arrived in one of the best shipping boxes I’ve seen to date — in double, corrugated cardboard boxes. The thing you see first is the model’s wing bag and wing jointer tube. The model’s parts are individually bagged. The production numbers on the bags and inside the fuselage told me this was number twelve. It was immediately evident, upon removing the parts, that this ARF is of exceptional quality. The Toughlon STL and Lightex SGX coverings used RC-SF.COM
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REVIEW
The attractive, scale design lines of the AeroWorks Laser 200 are complimented by our beautiful cover model Liz Jackson. The Laser sports a 76-in. wingspan.
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30CC LASER 200 ARF
YOU CAN DOMINATE THE COMPETITION WITH THIS LASER IN YOUR CONTROL!
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aser 200 aircraft have a rich heritage! The original may be best known for the fact that Leo Loudenslager won seven United States Aerobatic Championships between 1975 and 1982 in his. He also stood on top of the podium in 1980, winning the World Aerobatic Championships flying his Laser 200. The Laser originated as a Stephens Akro, but was completely modified and redesigned by Loudenslager to have a forward
BY Wil Byers
fusealge, as well as new wings, tail surfaces and cockpit. His Laser 200 was lighter weight, stronger and had a more powerful engine, so he could fly more difficult maneuvers. The Laser was capable of letting Loudenslager fly tumbling and twisting maneuvers, but also more precise aerobatics. His airplane has had a significant influence on today’s generation of aerobatic airplanes, including the Extras. Leo’s Laser 200 now hangs in the
Boeing Aviation Hangar at the Steven F Udvar-Hazy Center as part of the Smithsonian National Air and Space Museum in Chantilly, Virginia. AEROWORKS What attracted me to the AeroWorks Laser 200 30cc ARF was its fidelity to scale, quality of build and affordability. If you compare the AeroWorks Laser to the aircraft hanging in the museum, you’ll see AeroWorks’
Your AeroWorks Laser 200 will come with the fuselage, wings and stabilizers covered, and the cowl is painted to match. It uses very high quality wood throughout. We like that the bottom of the wings are done in a contrasting color scheme, which makes for excellent in-air visibility. Notice the carbon wing joiner.
AeroWorks provides a complete hardware package for their Laser 200. It even includes their CG Buddy and a nice set of decals. facebook.com/rcsportflyer
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