Hangar 9 Large Piper J-3 Cub
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The world famous Cub bear logo has already been applied to the fin of my new Hanger-9 106” wingspan, 1/4 scale Piper Cub. This is a finished model that looks very real, both on the ground and in the air. Could this be the next model after your trainer? Many new RC pilots start in the sport because they are attracted to certain full-size airplanes and want to fly a model of them.
Unfortunately, many brand new RC pilots want to learn to fly RC on their favorite airplane like a Spitfire, a P-38 Lightning or an F-15 Eagle. Unless the pilot is using either the Hangar 9 P-51 Mustang or F-22 Raptor Progressive Training System (PTS) basic trainers, this is usually not a good idea. Lacking a PTS trainer, a much better approach is to learn basic piloting skills on a traditional RC basic trainer like the Alpha 40 and then convert to a scale airplane that is somewhat easier to fly as a second airplane.
Once they have become reasonably proficient on a basic trainer (maybe the Alpha 60?), pilots thinking about flying “scale” will most likely turn to a lightly wing loaded (light weight with a lot of wing area), high-wing scale airplane. Jets (with propellers), multi-engine aircraft, aerobatic scale airplanes and warbirds make better third or fourth airplanes than they do second ones.
There are several such models that are easy to fly and will capitalize on the skills developed with the high wing “trainer” style of airplane. One very popular example is the venerable Piper J-3 Cub. (Ed. Note: Model Cubs do not make great basic RC trainers because they are short coupled, have much adverse yaw, handle poorly on the ground, tend to flip over on landing, do not “cover” piloting mistakes and generally excel at frustrating brand new pilots much like their full-size counterparts do)
The selection of available ARF J-3 Cubs rivals that of the Mustang. But “they” say that bigger RC airplanes fly better than the smaller versions. (Ed. Note: And, some do fly better). If this is true, then the new Hangar-9 1/4 scale J-3 Cub should be a great second airplane for scale minded pilots.
Photo 1
With its 106-in. wingspan and 69-in. long fuselage, the Hanger-9 Cub is a big ARF that will let you both fly a scale model and also try your hand at a larger and perhaps, easier to see aircraft. The Hanger-9 is a Piper J-3 Cub that is a very detailed model of the full-size airplane. It is so authentic that you could easily mistake it for its full-size counterpart both in the air and on the ground.
The Hanger-9 106” Cub is available in two versions. One is called a “Plug-and-Play” RTF (ready to fly) that has almost everything already done for you. The Zenoah G-20 gasoline engine and JR digital servo installations are factory complete. You buy it, install your receiver and you are virtually ready to go; right out of the box. While a great deal at $1,100 for the quality and equipment you receive, it still is a cost of over a thousand dollars.
The other, and less expensive version, is a $500 ARF (Almost Ready to Fly) version. With the ARF you choose the engine and radio that you would like to use. If the pilot already has suitable radio and engine equipment, this is also a very good deal
Photo 2
This review covers the Hanger-9 version that is an ARF. The engine chosen was a Mark M 210 2-cycle engine. (Ed. Note: Leave it to a Pattern flyer to stuff a 2.10 cubic inch engine into an airplane designed for a 1.00 engine. Just what is wrong with us Pattern flyers that an airplane must be overpowered to fly “right”?)
You might recognize this as a MOKI engine and you would be right. The good news is that they are now available from Hobby People (http://www.hobbypeople.net/). The new MARK engines are identical to the MOKI engines and all of the parts are MOKI compatible and supported under this new name. (Ed. Note: When not writing or reviewing, Eric manages a large and complete hobby shop located in NJ. Can you guess the name of this hobby shop from photo 2?)
The radio control guidance system chosen was a 2.4 GHz Spektrum-converted JR10X, affectionately called my 10X24. A nine-channel Spektrum R9000 receiver was available so it was employed to operate the servos. You could use a four-channel receiver and some Y-leads etc, but individual servo programming is available with the computer radio. This Cub uses two servos for the elevator. The dual-elevator-servo option made life a bit easier during the final programming of the radio set-up.
OVERVIEW
Hanger-9 introduced their new Cub as a large scale airplane over which the enthusiast would marvel. This is a giant scale, IMAA-legal (International Miniature Aircraft Assoc.), J-3 Cub. Hanger-9 claims that their 1/4 Scale J-3 Cub is a great-flying, large scale airplane that is perfect for a first time large scale flight experience because of its smooth flight characteristics. Maybe they could have added that it is a good second step trainer for pilots who want to go to a bigger airplane rather than to one that was faster or simply harder to fly than their original trainer. Also, it allows you to be just a little different.
A host of different engines can also be used on an ARF Cub of this size. At first glance, the MARK M 210 might appear to be a bit oversized. However, it was intended always to be flown at medium/low rpm with a large propeller such as a 19 x 8 in. or a 20 x 6 in. Running at lower rpms produces a more scale sound and makes for longer flights on one tank. It did not hurt that the MARK M 210 runs on the less expensive straight fuel, otherwise known as FAI. There is no nitromethane in this type of fuel, which bodes very well for both engine bearing life and the health of your wallet. (See Engine Section following this article.)
Hangar-9 has thought of just about everything to make this large scale Cub a good looking, sport scale replica of the ever-popular Piper J-3 Cub from the fully functional door right down to the scale dash with Piper Cub emblem in the tachometer. It has a more realistic Cub outline facilitated by tubular construction of the top fuselage contour. Likewise, the scale fin-to-fuselage fillet molding echoes its full-scale counterpart. The scale Cub wheels and fully functional landing gear facilitate easier landings, touch and go excitement and one-wheel arrivals.
Scale fans should like the full-bodied pilot figure that is not only of accurate scale, but pose-able. The factory-fitted operating door panels offer easy access to the interior of the airplane. The interior seating locks into the cockpit floor and can be removed for radio equipment access.
The design features collapsible wing struts that are connected to the wing with a pivot, while a pin-and-cotter key system allows the struts to be removed from the fuselage without hassle. The 2-piece stab can also be removed if necessary.
For those of you who like lots of construction detail, you can read and/or print the manual without buying the Cub, just by Clicking Here.
Contents
Photo 3 Photo 4
The fuselage comes with a fully operating lower door and the upper hinged-window frame already fitted. Both work well.
Photo 5
A close up of the door hinge detail and wing-tube position. There is a generous slot for wing servo extension lead and access.
Photo 6
Photo 6 shows the cabin area as seen from above through the cabin roof window frame. Many ARF J-3 models seem to forget that this cabin window even existed. But Hangar 9 has it in the right place and in the right scale size.
Photo 7 Photo 8
The interior is already set up for the single rudder and twin elevator servos. Slots in the floor accept the seats and cabin detail components. The area inside the fuselage is very large. There is more than enough room for the radio equipment.
Photo 9.
The vertical fin has the Piper Cub decal factory applied and the fuselage slot for the stabilizer is fully prepared to accept the bolt-on stabilizer.
Photo 10
The stabilizer will be bolted on to the four tabs that are already fitted with the T-nuts shown in the photograph. Stabilizer struts/stays will be needed to keep the stabilizer and vertical fin supported during flight.
Photo 11 Photo 12
The pre-painted fiberglass cowl comes with good engine detail, including staggered cylinders, factory installed. Most ARF Cubs require the builder to install the cylinder heads but Hangar 9 does that task for you. The fiberglass cowl is a good color match for the covering on the fuselage.
The wing panels of this airplane are large and yellow. You will get used to the color yellow as you are building this airplane. The wingspan is 106” which, if fully assembled, would make it a bit unwieldy to handle. Hanger-9 has come up with a design that uses two panels joined by an aluminum wing-tube. The two wing bolts that hold the wing to the fuselage also hold the panels together to form a single wing.
Photo 13
The airplane was designed with a two-piece wing to simplify attachment, removal and transportation.
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The underside openings are for the servo hatch plates.
Photo 16
The wing bolts are fitted into the root ribs from inside the cabin. A single servo in each wing is employed to operate each aileron.
Photo 17 Photo 18
The lightweight aluminum wing struts are pre-painted and hinged for storage and transport. The aluminum wing joiner tube has a black anodized coating.
Photo 19
The recessed hard points in the wing panels are for the wing-strut mounts and hinging.
Photo 20
Photo 20 shows the welded hinge point for the center support struts for the long wing struts. The short struts fold flat after disassembly for easy transport.
Photo 21 Photo 22
There are strings taped inside the wing panels to help pull the aileron extension leads through the wing panel. Remember to tie the aileron servo wire to the servo wire extension before installation to prevent a servo’s being disconnected. The wing’s center anti-rotation pin is already fitted to each root rib. The wing tube can be easily removed for transportation.
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There are many parts to the landing gear as there are on the full-size Cub. But assembly is easy and well covered in the photo instructions.
Photo 24 Photo 25
The landing gear is made using fully pivoting tubular construction. The suspension springs are operational and functional. The flight tests showed just how functional and realistic this flight gear really is.
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Close up of the main mounting bracket and the support for the removable axle wheels. This is a very strong landing gear arrangement and it functions well.
Photo 28
The tail wheel assembly features a carbon-fiber spring-leaf and a tiller system attached to the rudder with springs to absorb the effects of landing. This is light and strong construction.
Photo 29 Photo 30
The Hangar-9 Cub is fitted with a complete cockpit kit that is included in the kit. On an aircraft of this size, the interior is nearly as visible as are the wings. It is worth it to take some time on the cockpit as it will pay appearance dividends for years to come. (Ed. Note: Large Cubs do tend to live very long and useful lives as they are easy to see, easy to fly and enough fun that they will stay active in a pilot’s fleet for many years.)
Photo 31
The cockpit interior is complemented by the supplied double and single seats that are “keyed” into the cabin floor.
Photo 32 Photo 33
The included pilot is a realistically proportioned cloth doll that is filled with fluffy foam and a wire frame. The frame can be bent to any position. The life-jacket, helmet etc. can all be removed,
Photo 34
A one-piece cockpit windshield completes the exterior of the cabin area.
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A series of pre-painted plates are used to cover the cabin floor and the rear servo and radio installation. Black rods are used to simulate the cabin supports that are visible in the front of a full-size Cub.
Photo 37 Photo 38
The instrument panel is double layered with a clear set of dials that look very functional indeed.
Photo 39 Photo 40
The stabilizer comes in two halves, similar to the wing. The vertical fin is already an integral part of the fuselage.
Photo 41 Photo 42
The rudder and elevators are very realistic. The stabilizer, vertical fin, elevators and rudder all match the wing covering color. The fuselage top uses tubular construction, like the full-size, to retain the Cub’s unique dorsal appearance. The vertical fin is faired into the fuselage top using the covering just like the original.
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The “tail-feathers” are of built-up construction and although they are very strong, they will definitely need the pre-painted wire braces supplied with this airplane.
Photo 46
All of the bolts and assembled components were removed from their plastic bags and compartmentalized in a “box o’ bits” for both identification and quick access during construction. The included hardware is what makes this a comprehensive kit. There really was nothing left out except for the engine and radio.
Photo 47
The kit contains the fuel tank and tubing already assembled. There is a lot of prefabrication done on this airplane; far more than is usual with an ARF kit.
Photo 48
All the parts you need to make a pull-pull rudder system are included. Pull-Pull rudder systems use two cables, one from each side of the servo output arm, to move the rudder instead of a single wire pushrod. A pull-pull system is more exact and centers better than a control rod in aircraft of this size.
Photo 49
Even all the bolts required for the engine and engine mount installations are included. The Hanger-9 accessories consist primarily of US-threaded bolts and full length 4-40 pushrods. A nice touch is that they are threaded on both ends for the 4-40 clevises. Metric size bolts are not used on this airplane which simplifies assembly.
Construction
Before you get going, a useful thing to do is to cut up the box-lid and isolate the smaller detail pictures. Arrange them like a series of construction photos. They help in making positioning decisions, and function like “cue” or “crib” cards. They also provide easy access to data such as weight, etc. It can also be rewarding to keep one big box lid picture for historical purposes if you intend to build your own personal wall-of-fame.
A big negative with almost all iron-on film covering is that most ARFs arrive with everything wrinkled to one level or another. The manual addresses the issue but it is still a pain to re-iron any covering. You are, however, given good advice and instructions on how to do the heat-shrinking of the covering to remove any wrinkles induced by storage temperature changes.
This ironing may well not be the easiest of tasks. It is strongly advised that new “builders” seek the help of an experienced modeler for this task. A heat-gun was carefully used in a few places to tighten up the open frame covering material. (Ed. Note: If you have not removed wrinkles many times before, be careful. Don’t use a heat gun unless you are very experienced at this procedure. Heat guns can make the covering crawl, slip over itself at an overlap point. The covering recedes but the wrinkles stay. Use a modeling covering iron instead. Make sure to seal all overlap areas first, before trying to remove the wrinkles themselves.)
Engine:
Photo 50
This ARF comes with a firewall template for several engines, including electric and gas power. This is an excellent feature that makes this airplane especially easy to build correctly. An “executive decision” was made to side-mount the large glow engine instead of mounting it inverted. Using the supplied reference lines on the firewall, the engine mount was rotated as shown. The idea was to expose the cylinder head to the cool air outside of the cowl. Side mounted large engines are easier to make idle reliably than are inverted powerplants.
Photo 51
The fuel tank was raised to be in-line with the side-mounted carburetor and the engine mount positioned using the existing datum line. The Sullivan mount used is an “isolation mount” designed to reduce engine noise. The engine mount was drilled and tapped before positioning on the firewall.
Photo 52
The tank feed line was positioned to provide the shortest fuel route to the big MARK M 210 through a new hole in the firewall.
Photo 53
The engine was mounted as far back as it would go to help achieve the specified forward center of gravity and to keep the thrust washer close to the end of the cowling.
Photo 54
To support the bigger engine, triangular stock was added to the firewall. Then the whole face of the firewall was fuel-proofed with 24-hour finishing epoxy resin. The masking tape patches prevent the glue from getting into the threads of the T-nuts.
Photo 55 Photo 56
The Bisson muffler (http://www.bissonmufflers.com/) is a “Pitts Style” design and fitted snugly under the side-mounted engine. A “Pitts” muffler redirects the exhaust from a side mounted engine to exit out the bottom of the fuselage towards the ground. It is usually hidden inside the cowling.
Photo 57 Photo 58
By placing the engine on its side, the risk of flooding the big engine was greatly reduced and access to the glow plug was made much easier.
Photo 59
There is just enough room to thread the throttle pushrod between the engine and the muffler.
Photo 60 Photo 61
The MARK engine has an optional, in-flight remote high-speed needle. This is very useful when breaking the engine in during flight. The mixture can be increased or decreased from a knob on the transmitter. This is especially useful with a big engine because it allows the pilot to prevent any overheating due to lean runs in the early flights.
Photo 62 Photo 63
Initial cuts with a hot knife for the engine in the cowl are later sanded smooth by hand.
Photo 64 Photo 65
The rear of the oversized fuel tank was wrapped in black duct-tape to make it less obtrusive in the scale cockpit area. (Ed. Note: Hey Eric, use a reasonable size engine and the stock tank would have been large enough and invisible. But I still love oversize engines. Maybe I need treatment?)
Photo 66 Photo 67
The fuel is added and removed through a fuel dot placed high on the cowl near the remote mixture needle. The higher the fuel-dot is placed the less likely it will be that you will spill any fuel due to gravity-draining of the tank when the fuel-dot is not in the fuel tubing.
Photo 68 Photo 69
A rough cut for the exit of the exhaust stubs is made large to allow hot air to leave the cowl.
Photo 70 Photo 71
The final cuts are then sanded close to the engine so that no part of the cowl touches any part of the aluminum.
Fuselage Cabin:
Photo 72 Photo 73
Photo 74 Photo 75
A great feature of this ARF is the pre-fitted and functional cabin door. The large lever actually works to unlock the door and comes in handy when turning the on-board radio system on and off because the switch is hidden under the pilot’s seat.
Photo 76 Photo 77
Photo 78 Photo 79
Here are some more close-ups of the door showing the latch retaining pins.
Photo 80
Cockpit seat detail is included in this ARF. (The joystick is an addition fitted by the author).
Photo 81 Photo 82
An internal view of the decorative, but scale, cabin-brace through the front windshield.
Photo 83 Photo 84
You will have to spend some time fitting the windows to the fuselage. Masking tape was used to hold the windows in place while the RC-56 glue cured and hardened overnight. A screw was added to ensure the windshield could not come loose.
Photo 85 Photo 86
If you look carefully at photo 86, you can see that a tiny hole was drilled to allow a removable pushrod to reach the on/off switch without opening the cabin door. (Click on photo 86 for a larger size.)
Photo 87
A small piece of scrap wood was used to hold the aileron extension lead in place. This prevents the lead from falling back inside the cabin area during assembly.
Photo 88
Photo 88 shows the final view of the cockpit area with the pilot and seating as supplied by Hanger-9.
Main Landing Gear:
Photo 89 Photo 90
The J-3 Cub uses a scale-like tail-dragger landing gear configuration. The large Cub wheels have yellow hub covers that hide the ends of the axles to add more realism. Photo 90 shows all of the parts that you need to make the functioning Cub landing gear.
Photo 91
T-nuts (sometimes called “blind nuts”) are already installed in the fuselage for the landing gear mounting brackets.
Photo 92 Photo 93
It is important to use the correct length 4-40 bolts to hold and hinge the working parts of the landing gear.
Photo 94
Photo 94 shows the factory machined flat spot in the stub axle that will hold the single wheel collar on the axle. The flat spot provides extra “bite” for the wheel collar set screw and insures the wheel stays on even while the wheel collar is hidden behind the hub cap.
Photo 95 Photo 96
There is a sturdy metal bracket on each side that is used to hold the main landing gear in place as well as the wing struts.
Photo 97 Photo 98
While the kit-supplied wheels are excellent, I just happened to have a set of inflatable “Cub” wheels on hand. These wheels air-cushion the landing and really make the detailed landing gear stand out. The inflation air-valves operate just like the ones on your car.
Photo 99 Photo 100
The carbon fiber tail wheel assembly is both strong and light. Few manufacturers will spend the extra money to supply such quality as this tail wheel. That Hangar-9 did is just one small example of this airplane’s very high quality.
Stabilizer and Rudder:
Hanger-9 positions the two elevator servo arms pointing inwards from either side of the fuselage. This “opposite” action will require a reversing Y-lead to be used unless you have a computer radio that can employ two separate channels for elevator servo operation. If you do use a “Y” lead to the receiver’s elevator channel, try using one of the amplified “Y” connectors as this is a large airplane with higher current demands.
Photo 101 Photo 102
Extra Mylar hinge material was slotted into the elevators under the control horns’ positions to provide a more sturdy support for the horns on the large elevators. Cut the reinforcement Mylar hinges flush with the elevator leading edges.
Photo 103 Photo 104
Pins were used to center the Mylar hinges. They are removed just before applying the thin CAA glue. For complete details on how to install the durable Mylar laminate hinges that are used in most of today’s RC aircraft, read the Sport Aviator article: “Installing Mylar Hinges” in the Flight-Tech Section
Photo 105
The horn bolt positions were drilled through the elevator and the Mylar hinge material.
Photo 106 Photo 107
The wire pushrods were used to line up the position of the elevator and rudder horns prior to fitting the extra Mylar material and the subsequent drilling.
Photo 108 Photo 109
Fitting the stabilizer is often considered to be the most difficult part of the assembly of any airplane. The horizontal stabilizer must be exactly parallel with the wing. If one side is lower or higher than a wingtip, the airplane will try to roll when elevator is inputted. This stabilizer comes in two halves and is simply bolted in place. It did not require any adjustment of the stabilizer fuselage seat.
Photo 110 Photo 111
Rudder-horns were fitted on both sides of the rudder and were held in place with the longer 2-mm nuts and bolts. The rudder movement will be controlled by pull-pull cables from the rudder servo mounted forward in the fuselage. Since the rudder also controls the steerable tail wheel, reinforcing the area under the control horn with part of a hinge as mentioned previously is strongly recommended.
Photo 112
Pin holes were strategically made in the built-up control surfaces to allow excess air to escape from the sealed stab and elevator bays in hot weather and during re-shrinking of the covering material. This is especially useful when using a heat gun to remove wrinkles.
Photo 113 Photo 114.
Pre-finished braces are provided for the fin and stab assembly. They are structurally-functional and must not be omitted. The full-size Cub also used these braces so the Hangar 9 version remains true to the original.
Wing Assembly:
Unlike so many ARF aircraft, assembling the Cub’s wing is almost a no-glue-required process. A lot the usual construction time is saved because there is no need to glue wing halves together. The ailerons are hinged with Mylar-hinges. This makes the hinging task very quick and simple. A few drops of thin CAA later and the ailerons are ready to use.
Photo 115 Photo 116
There is an aileron servo mounted in the wing for each aileron. The servo mounts to the hatch cover which is then screwed in place. Most builders just try to position the servo mounting blocks using the servo itself. This is difficult as the servo slides around and the wire lead seems to always be in the way. Plus, you don’t want to epoxy the servo to the hatch by mistake.
Photo 117 Photo 118
A “card” spacer was cut to the servo size and positioned on the hatch cover so that the servo arm fits into the slot. In addition to positioning the servo mounting blocks, the card keeps the servo away from the plywood while the screw holes were drilled. This gap keeps the engine vibration away from the internal workings of the servo.
Hanger-9 built the wing panels with a piece of string already inside the panels. This lets you easily pull the long servo leads through the wing. Remember to tie the aileron extension lead’s connector to the servo connector using strong thread so it can not come apart inside the wing.
Photo 119 Photo 120
The servo is installed flush with the surface of the wing. All that is left to do is expose the inlaid ply-plate in the ailerons to accept the right and left control horns. Note in photo 120 that two small screws are used to reinforce the epoxy holding the servo mounting blocks to the hatch cover. The four outer holes mount the hatch cover servo assembly to the wing.
Photo 121
The completed servo and pushrod installation is neat and more than strong enough for this giant airplane.
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Photo 124 Photo 125
The functional wing struts are bolted to the wing. The nearly vertical center struts attach to the wing using removable clips (photo 123) and to the struts themselves with bolts (photo 124). These center struts are hinged so they fold flat against the wing strut when the airplane is disassembled. The center struts prevent any in-flight oscillation of the long struts. Each strut assembly is bolted to the fuselage using the landing gear mounts attached in photo 95.
Photo 126 Photo 127
Closer shots of the very real looking “scaffolding” that constitute the rigging of a Hanger-9 Piper Cub wing. Looking completely the part, the Hangar-9 106” Cub is all dressed up and ready to go.
Radio Installation:
Photo 128
Hangar 9 extended the wing strings for aileron servo leads into the fuselage to help pull the leads up inside the cabin walls.
Photo 129
While the fuselage interior may look crowded at first, access was relatively easy through the large cabin side-door. A short-handled screw driver really helped as well.
Photo 130
Two elevator-servos and one pull-pull rudder-servo are well hidden in the fuselage behind the rear pilot’s seat. Make sure that checking every servo for the servo arm retaining screw is part of your first pre-flight check before flying. All three are missing here as final adjustments have yet to be made.
Photo 131 Photo 132
The throttle servo and an additional in-flight needle mixture servo were fitted just in front of the pilot’s feet.Having an in-flight mixture control is not mandatory and most Hangar-9 Cub’s will be cruising the air without one. But it sure is a handy gadget to have in a scale airplane.
Installation of a 2.4 GHz R9000 Spectrum receiver proved to be a very easy task. There is plenty of room for the receiver and battery provided by an additional plate that hides the servos. This receiver mounting plate is then also covered over by a pre-painted plate behind the pilot.
Radio installation tip: It is a very good idea to use two different aileron extension leads coming out of the receiver. They need to be labeled on the wing and in the fuselage. Check carefully that they are all plugged in correctly before flying! Computer radio settings allow you to set the right and left servos at different centers, trims and throw endpoints. You can use a Futaba and a JR extension to prevent wrong physical plugging. The servo-leads coming out of the wing halves were set up with matching JR and Futaba plugs.
Building Summary:
The Hanger-9 J-3 Cub is no harder to build than an ARF Trainer. True, it is larger, but it is a straightforward build and has high quality-parts that fit together very well indeed. The instructions are first class. There is very little for the builder to do that requires much prior R/C construction experience.
In point of fact, this airplane is easier to build than the average ARF trainer. The wing is not glued together so getting the halves aligned is not critical. The stabilizer screws to the fuselage so stabilizer – wing alignment is factory correct every time.
If you mess up during building or later on at the field there are plenty of readily available spare parts available from Horizon Hobby. This is a pretty big deal because if you fly an RC airplane you will damage it sooner or later. You may simply give it “hanger rash” moving it around the garage. No matter, Hanger-9 has a full and fantastic set of replacement parts waiting for the results of your minor indiscretions.
TIME TO GO FLYING.
At The Field
Photo 133
The Hangar-9 J-3 Cub is very impressive and too big for the club’s benches. A little “bench reinforcement” was needed to hold the airplane up during assembly to protect my old back.
Photo 134 Photo 135
A strong, light aluminum spar holds the wing halves in place. Slide the right wing half in place over the spar. Be sure to connect the aileron lead. Each wing half is held in place using a single 1/4 x 20 nylon screw. Replace the nylon screws supplied with socket head nylon bolts (available at any hobby shop).
Use either a 3/16 “ball driver or Allen wrench to insert the nylon bolt through the hole in the left side of the fuselage (photo 135). Tighten the right wing in place using the wrench or ball driver. (Ed. Note: A true Allen wrench works best for this as it grips the bolt head more tightly than does a ball driver. However, a ball driver is required to install the left wing panel.)
Photo 136 Photo 137
The wing-strut is then secured to the fuselage. At the base of the fuselage, 4-40 bolts and locking nuts were substituted for the supplied pins and spring clips to create a tighter fit that would not rattle.
Photo 138 Photo 139
The spring clips and lock nuts are kept in a plastic pill bottle. It is also a good idea to carry spares. The grass will eat a critical piece sooner or later. A small socket wrench was used to finger tighten the 4-40 nuts.
Photo 140
The center-strut supports are unfolded and positioned next. The locating pins are used with the spring clips to attach the center strut supports.
Photo 141 Photo 142
With the right wing securely attached, fitting the left wing-panel is a much easier step.
The servo leads are connected just before the wing bolts are added and the left wing-panel pushed up snug to the side of the fuselage. The second 1/4 – 20 socket head nylon bolt is then inserted through the cabin side door. A ball driver is a must here as tightening the bolt through the door prevents using a straight line. The tool must tilt upwards a little to reach the bolt head. Regular Allen wrenches will not allow much tilt but ball drivers will.
Photo 143
Shown in photo 142 are the foam pipe insulation wing protectors that are used to keep the center struts away from the covering during transit. I like this idea better than folding the center struts against the wing strut but that is only a personal choice. Before installation, the foam is removed and the struts clipped into place.
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All you have to do now is add some fuel and start the engine. (Ed. Note: I warned you that Eric manages a Hobby Shop in New Jersey, Remember?)
Breaking In The Engine: (See Engine Detail Section At The End Of The Article)
Photo 146
The whole airplane is well secured before starting the engine. Visible, smoky exhaust coming out of the exhaust deflector is a good sign when you are breaking in an engine. The MARK M 210 engine was brand new and needed to be broken in before it was used to fly the airplane. This engine uses no nitromethane and took two tanks of “FAI” fuel to get a reliable engine run. A reliable engine run is defined here as when the engine will hold full throttle for a couple of minutes and then go back to idle without running fast or hot.
This engine was very easy to operate. It started first flick and ran well at the pre-set factory main-needle and idle adjustment settings. (It is always a good idea to richen the main needle a few clicks and hold the airplane with its nose pointing at the sky to simulate a steep climb out on take-off.)
An OS “F” style glow plug and Cool Power FAI fuel allowed the M 210 to run rich without dying or loading up. Setting the needle slightly rich will also allow for the slight reduction in fuel flow as the fuel level gets lower in the tank. Setting the motor slightly rich compensates for all of these conditions and keeps the engine cool and well lubricated during the entire flight.
Flying:
Before describing what it is like to fly this exceptional airplane, I would like to offer my special thanks to members of the Pine Barons NJ club for some clear airspace for test flying and to the members who manned the video-cam and still-camera. Bob Tucker and Anthony Desimone did the video work and Dean Anthonson handled the still camera while the J-3 Cub was put through her paces.
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Photo 149 Photo 150
The Giant Cub is all dressed up and ready to fly. Building this airplane was a real pleasure. If it flies as well as it was easy to build, this is going to be a very good day. The sun is out and there is very little wind; a perfect day for Cub test flights.
Photo 151 Photo 152
Tail feathers all braced up. A 20 x 6 break-in propeller was fitted with a TruTurn Hub nut. The TruTurn hub nut is a special form of spinner and needs an adapter nut to retain the spinner cone. It is available at any Hobby Shop. This nut will accept the 8-32 spinner bolt that holds the TruTurn spinner hub firmly in place. Even the pilot was ready!
Photo 153 Photo 154
The Mark 2.10 cu. in. engine fits well in the airplane. The Bisson muffler directs the engine exhaust out of the cowling on the bottom. Such mufflers are known as “Pitts Style” mufflers since their first modeling use was on a very large Pitts Biplane scale model.
Photo 155 Photo 156
A little peek underneath and some more views show all of the aspects of the big Cub.
Photo 157
A 1-1 scale, real human, Tony Matyi, and a JR10X transmitter pose with the Hanger-9 Cub to show the relative size of the airframe.
Photo 158 Photo 159
A good twenty minutes was spent on the ground running the engine until there were no signs of overheating with sustained full and half throttle settings. These tend to be the two positions used during flight. The half-throttle position’s performance is a tad more critical than the full throttle position since the engine could be running slightly lean, less fuel and more air, at half-throttle. This is also where the engine will be running most of the time. You can throttle back from full-throttle if the engine is over-heating, but you will quickly lose flying speed, and altitude, if you can’t maintain a mid-throttle setting without overheating.
Photo 160
The 106” Cub is a bit too big to carry with the engine running so it was taxied out to the center of the runway. Playing for time with a slow taxi out to the take-off point also tests the engine to see if it wants to die or do anything you don’t like before you decide to take off. But really, it just helps calm your nerves.
Photo 161 Photo 162
It is time to advance the throttle as there were no more excuses left. The Hanger-9 Cub did not disappoint. The take-off was quick and easy. The throttle was quickly brought back to about 1/2 as soon as the airplane was airborne. The good lift from the large wing panels was very evident early in the take-off run. The Hanger-9 J-3 Cub was rock solid. No sign of any problems with pulling to the left or the right at low airspeeds.
Photo 163 Photo 164
Some low passes for the camera. This is a beautiful airplane in the air. Slow speed control was near perfect. Having the ailerons on two separate servos allows the pilot to trim out any adverse yaw tendencies but there really wasn’t much of that to worry about.
Photo 165 Photo 166
Photo 165 is another slow and low pass. This time with the wing dipped followed by a slow climb out. The airplane’s rudder is very effective so not much opposite rudder was required for straight flight.
Photo 167
A little knife-edge required some opposite aileron. Although the Cub is not designed for aerobatics, it is a pretty capable machine. Just leave yourself a bit of altitude to recover from any mistakes.
Photo 168 Photo 169
You can spend all day doing scale fly pasts and low, slow realistic flying. Just remember to keep an eye on your flight timer when doing all those extra passes for the cameramen. (It really helps to have more than one guy with a camera.)
Photo 170
Even while turning in for final approach, the Cub looks great and poses no problems, even for a brand new solo pilot.
Photo 171 Photo 172
Landings are very easy. Just line-up on the runway, throttle back and fly the airplane down until the wheels touch and the airplane’s tail comes down and rolls to a stop. (Ed. Note: Many pilots have problems keeping a Cub on the wheels at touchdown. Even when landing at slow airspeeds, any J-3 model tends to flip over. Usually there is no damage but it is embarrassing. Here is the secret to landing a J-3 and keeping the wheels pointed at the ground.
Throttle all the way back while on short final approach. Use “up” elevator to slow the airplane without gaining altitude. Keep the airplane descending while using the elevator to slow down. When you think that the airplane is so slow that it is going to fall out of the sky, reduce the airspeed by another 30%, again using “up” elevator. But make sure the airplane is always descending slightly. Add power if the touchdown point is going to be too short. The Cub has so much wing area and is so light weight that the proper touchdown airspeed is so slow most pilots just are not used to it. So they tend to land slightly fast and over she goes.)
Photo 173 Photo 174
A well earned slow taxi back to the pits after a successful first flight.
Flight Summary:
Throughout the flight, the engine was periodically opened up and throttled back for down lines and slow passes. This ensured that the engine could cool off between the periods when it was generating a lot of power. The MARK M 210 never complained or hesitated or sounded like it would stop, not once! Be aware that if you go to full throttle you can fly out of sight very, very quickly.
The landings were easier than with a trainer. This is because you just line up on the runway and cut back to idle. The airplane sinks steadily when slowed down. The ailerons work all the way to the touchdown. A high-low idle switch was used for the final landing moment to bring the idle right down.
The flight tests included several aerobatic maneuvers. It did very big and straight inside loops. It will fly inverted just as well as the right way up. A very respectable stall-turn can be done with the application of rudder. Axial-rolls were slow but relatively easy! There was very good knife-edge flight due to the large side-area but it needed opposite aileron to the rudder input to hold the wings in the vertical plane.
Overall, the Hanger-9 J-3 Cub is easy to fly and land. The recommended control surface rates were very good. Low rates flew the big airplane like a trainer. This airplane will float, but if you go really, really slowly it can still be stalled. The stall is pretty gentle but it will lose about ten feet of altitude. So try not to stall it at nine feet!
The Hanger-9 J-3 Cub feels like a full-size Cub on the ground and in the air.
The first flight was really great. All of the flight tests were a great success. No problems with steering on take-off or landing. It is a very solid flyer in the wind. You appreciate the benefit of good maneuverability and responsiveness when flying in a breeze or when you encounter unexpected turbulence.
Transitioning From A Trainer?
This airplane should probably not be a first R/C airplane. However, because it is very stable and pleasant to fly, it could be a very good choice as the “next level”.
The aileron control responses at the recommended low-rates were just like a trainer would fly. The airplane flew very well throughout these tests and had a better feel than a basic trainer.
Hanger-9 has come up with an IMAA-legal scale plane that looks good in the air and will fly just as well as it looks.
Ready-To-Fly Version (by Editor)
As previously mentioned, Hangar-9 also offers this same aircraft in a Plug N’ Play version (PNP). Everything is included and installed except for the transmitter and receiver. The PNP version includes the new Zenoah G-20ei gasoline engine, a 16 x 6 propeller and spinner, six JR PS 821 digital servos and both ignition and receiver battery packs. The airplane arrives fully assembled and the cost is $1,100 plus $100 shipping. If time or your assembling skills are short, this is the best way to get a true-scale J-3 Cub that you will enjoy for many, many years. Cubs are very hard to hurt. There are Cubs flying at my various club fields that are more than 30 years old. Many more are 20+ years old and still fly well. A large J-3 Cub is not a purchase; it is an investment that will last as long as its pilot allows it to.
Q
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Specifications Manufacturer: Hangar 9 Cost: $500.00 Special Airframe Features: Fuselage top actually to scale, Strong wood construction; Tough Ultracote covering; Full interior. |
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Notable Positives Notable Negatives |
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Type: Scale |
The Mark M-2.10 Engine – A Closer Look
Photo E1 Photo E2
The MARK M 210 is a mighty engine that is now available from Hobby People or your local hobby store. They also have the 135 and the 180 cu. in. versions available. The engine will be very familiar to former MOKI users. It is identical in almost every way. It will turn a nice big propeller that allows the Cub to cruise around the sky on 1/4 throttle all day!
Photo E3 Photo E4
The M-210 has classic MOKI lines surrounding a powerful 2-cycle engine that uses no nitromethane. Since most of the world does not have access to low-cost nitromethane, their engines are designed to run on fuels containing only methanol, oil and a few percentage points of film formers, igniters and other additives. This is called “FAI Fuel” since that is the fuel specified in most international model competitions which are governed by the Fédération Aéronautique Internationale (FAI). Most 2-stroke glow engines sold in the US do best on fuels containing at least 5% nitromethane.
Photo E5 Photo E6
Photo E5 shows the front of the carburetor stamped “MOKI”. But photo E6 shows the crankcase labeled for Mark M-210.
Photo E7 Photo E8
The rear backplate can be replaced with a radial mount backplate for easier mounting.
Photo E9 Photo E10
Large, deep cooling fins cover an almost hemispherical shaped combustion chamber. “Hemi” heads provide a more efficient combustion that yields greater power. Six 3-mm bolts hold the head in place.
A flat-headed piston runs in a heavily ported liner that moves large amounts of fuel/air mix into the massive 2.1 Cubes of the MARK M 210.
The engine’s 1.38 in. bore and 1.34 in. stroke actually yields a 2.11 cu. in. displacement. The Mark M 210 weighs 48 ounces with muffler, slightly more than the muffled G-20ei’s 42 oz. However, the M-210 produces 4.5 hp which is 265% more than the G-20ei’s 1.7 hp.
(Ed. Note: Trust a Pattern Pilot to stuff a huge engine into the smallest airframe possible and then claim the combination has “just enough” power. But actually, this is a great combination for extensive aerobatics while still allowing slow flight and realistic sound.)
Photo E11 Photo E12
The MARK M 210 carburetor has a tapered venturi and employs a rotating body type of low-speed mixture adjustment. This allows very precise idle mixture adjustments for those slow fly-bys.
Photo E13
The side-mounted MARK M 210 fits snugly in the cowl of the Hanger-9 J-3 Cub. There is no shortage of power from this engine when hauling a 106” airplane around the sky.
Short URL: http://masportaviator.com/?p=845
Posted by Eric Henderson
on Filed under Sport.
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