Piccole Ali

Aeromodellismo dinamico online

2009 Piccole Ali – Stra’ (Venezia) - Italia

AEROMODELLO RADIOCOMANDATO

RADIO CONTROL MODEL

DOUGLAS A-26 “INVADER”

VQ MODEL DOUGLAS A-26 “INVADER” ARF 46

Apertura alare / Wing span: 1727 mm

MOTORE A SCOPPIO / GAS POWER

2-Tempi / 2-Stroke: 0.46 ci (X2)

4-Tempi / 4-Stroke: .52 ci (X2)

MOTORE ELETTRICO / ELECTRIC POWER

KV 890 (X2)

Produttore / Manufacturer: Distribuito in Italia da:

www.vqmodel.com www.piccoleali.it

www.piccoleali.it …passione pronta al volo !

2009 Piccole Ali – Stra’ (Venezia) - Italia

Il Douglas A-26 Invader (B-26 tra il 1948-1965) fu un bombardiere bimotore Nord Americano costruito dallaDouglas Aircraft Co. Originariamente fu costruito in due configurazioni. L’A-26B aveva un naso solido chenormalmente ospitava 6 mitragliatrici calibro 0.50”, ufficialmente denominato il naso multi-ruolo e più tardinoto come il naso da 6-mitra o il naso da 8-mitra. L’A-26C “naso di vetro” ufficialmente denominato naso dabombardiere, alloggiava delle bombe Norden per bombardamenti da media quota.

Nell’A-26 Invader un membro dell’equipaggio a fianco del pilota espletava il ruolo di navigatore e caricatoredelle mitragliatrici che erano operate dal pilota stesso. Nell’A-26C, il membro di equipaggio espletava il ruolodi navigatore e bombardiere ed era ospitato nel naso del velivolo. Un certo numero di A-26 fu equipaggiatocon doppi comandi una parte dei quali poteva essere disabilitata in volo.

Il modello

Fantastica riproduzione ARF dell’A-26. VQ Model ha catturato la grazia e la forza bruta di questo velivolo

con un impressionante livello di dettaglio, dalla pannellatura alle torrette-mitra. Le modello possiede ottime

caratteristiche di volo ed il direzionale è molto efficace, caratteristica questa indispensabile per un bimotore.

Siete pronti ad invadere lo spazio aereo del Vostro campo di volo?

Questo aeromodello e destinato agli aeromodellisti esperti e non presenta controindicazioni come primo

bimotore.

Caratteristiche del modello

Costruzione tradizionale in balsa e compensato delle migliori qualità

Dettagliato rivestimento in speciale pellicola polivinilica prestampata

Naca motore in fibra di vetro dipinta di fabbrica

Superfici di controllo già incernierate di fabbrica

Istruzioni dettagliate passo–passo in italiano

Caratteristiche tecniche – VQ Model A-26 Invader ARF 46 RC

Apertura alare 1727 mmLunghezza fusoliera 1374 mmSuperficie alarePeso 4970 gMotore a combustione interna 2-tempi / .40 ci 4-tempi / .52 ciMotorizzazione elettrica KV 890 Regolatore brushless 60 A

LiPo 4400 mAh – (4-5)SRadio 6 canali 7 servi

Accessori in dotazione

Carrello triciclo e ruote

Supporto servi

Castelli motore

Serbatoi

Ogive

Pacchetto hardware completo

Non incluso

Motori, servi, colla e tubo miscela

www.piccoleali.it …passione pronta al volo !

2009 Piccole Ali – Stra’ (Venezia) - Italia

Prodotti correlati:

VQ Model A-26 Invader ARF 46 (White)

VQ Model A-26 Invader ARF 46 (Black)

Motore ASP FS52AR RC

Electric pack EP-890

TwinSync by Wike RC: l’affascinante e realistico suono di due motori sempre sincronizzati…ed in più una

speciale funzione sicurezza

VQ MODEL DOUGLAS A-26 “INVADER” ARF 46

Aeromodello radiocomandato / Radio Control Model

By TwinnMan (from www.rcwarbirds.com)

During my "forced visit" by the owner of RCWARBIRDS.COM to review the VQ P-38. I had a

chance to visit with the designer of the VQ line over the items I was worried about during

the building of the review A-26 almost one year ago. He updated me on the changes most

of which came from the modelers in the field and maybe a few from me. (What is this world

coming to....a manufacturer who listens??)

1. As I live in Houston, it is very warm here most of the time and worse in summer. I was

commenting that the covering would wrinkle if exposed to direct sun light. Note, my plane

was black, so the effect was worse. I was assured that a light application of a heat gun, ( I

said Light) will permanently remove the wrinkles, but it might take up to three applications

of the gun ( Lightly) to make the material stop getting loose in the sun.

2. I had trouble mounting the nose gear. The original nose area did not contain a vertical

firewall, so top mount was the only option. The new models have a vertical firewall to

mount the nose gear and a push pull cable type gear for actuation.

3. The main gear mounting area is reinforced.

4. The front side of the engine firewall is now fuel proofed from the factory.

5. There were problems with the plastic attachments cracking. They have been replaced

with a completely new material that if much more flexible.

6. The canopy has been redesigned and material changed for increased durability.

These guy are really trying to improve their product based upon customer input......Color

me impressed!!

Model.............A-26 Invader

Airplane Type.......ARF Sport War Bird

Manufacturer........VQ Models

Suggested Retail Price.......$300.00

Anticipated Street Price.....$ 299.00

Wing Span.............Advertised....68.1 in.

Measured......68 in.

Wing Area.............Measured......777 sq. in.

Airfoil...............Semi-Symmetrical

Wing Structure........Balsa, ply, and hardwood leading and trailing edges

Wing Joiner Method....9" plywood joiner

Fuselage Structure.....Balsa, hardwood, and plywood

Fuselage Length........Measured..54.5 in.

Pushrods Installed.....Outer Shells for twin elevator and rudder

Hinges Included........Yes

Hinges Installed.......Yes

Rec. Controls..........Ail,El,Rud,Throt ( Requires Minimum 6 Servos, 7 with retracts)

Engine Mount Installed..........No

Engine Mount Type...............Two Piece

Rec, Engines....................Two .25-.32 2 Cycle

Two .40-.52 4 Cycle

Fuel Tank Included..............Yes

Rec.Fuel Tank....................8 oz.

Landing Gear Installed...........No Fixed included...Provisions for

Retracts

Wheels Included..................Yes

Rec. Wheels......................1.25"Nose, 2"-Main

Rec. Weight......................N/A

Assembly Instructions..........14 page picture book

Hardware: Metric or SAE.........Metric

Hardware Included...............Everything Required

Items Needed to Complete.....Propeller, two engines, radio, Six servo extensions, two

servo Y harnesses, two feet fuel line, Six Servos (Seven with retracts), foam padding for

two fuel tanks and radio, CA adhesive, 30 Minute epoxy, Assortment of 3/4" metal screws

for the control horns,4 of 1.25 " 2-56 Screws, Silicon sealant, and small 1/4" long wood

screws.

Covering Material.............Stick On Plastic Covering

Fuel Proofing Required........No, but recommended

Estimated Assembly Time....... 18-20 Std gear, 22-24 with retracts

Estimated Skill Required........Experienced

Drilling Required.............Engine Mounts, control horns, servo mounts, (Additional with

Retracts)

Assembly Tools Required.......Regular hand tools,drill bits, hobby knife, moto-tool, allen

wrenches, and scissors.

Completed Model

Finished Weight...................10lbs 4oz

Wing Loading.......................30.39 oz per sq ft

Engines Used..................... Magnum 52 four stroke

Propshafts to the Ground......7.5"

Fuel Tank Used...................As supplied

Radio Used.........................Futaba t6xa

Covering/Finishing used.......Pre-covered

Special Items.....................Added Spring Air Retracts, Hobbico Multipurpose and Areo

Gyroscopes, and MacDaniel on board twin glow driver system.

Cheers- Parts fit very good and straight, installation of the rudder sets dihedral of the

elevator halves, mechanical push rod divider included for the split elevators,' control

surfaces preinstalled, heavy duty stick on covering was straight and few wrinkles, aileron

servos had premade hatch covers, preparation for retracts already made, and what can I

say....It is a twin arf of a classic warbird.

Jeers.. Preglued elevators fell off in my hand during control horn installation, additional

wood trimming was required for proper fit of the plastic covers, wing servo mounts were

weak, wood attaching mounts for the engine nacelles were weak and split, and the picture

book instruction manual is not for the novice builder. (Please see update at top of page)

Building the Invader

As I am in the habit of flying only twins (See "Obsession in the dictionary) it was a natural

me to get interested in the new A-26 ARF by VQ Models. The kit comes in three colors,

white, blue, and black. I chose the black one..Into the night fighter stage!!

When I opened the box, I noted a complete kit in good shape and well packed.First things

first....Read the instructions before beginning the project. ( I thought I would try something

new!!!! For those of us who do not like or attempt to read the instructions first..I am here to

tell you life is good....There are no written instructions!!!! The whole manual is 90%

pictures and a minimum of written text. There is a legend for the obscure picture symbols

and little else.

Building the Wing

The precovered wing halves are fairly self evident from the pictures, as to how they go

together, using a single wing joiner of 1/8 ply with around 4" overlap in the premade boxes

in each wing half. 30 minute epoxy is used to join the two halves around the plywood

joiner. The joiner sets the wing dihedral at exactly the correct angle. The joint in as close

to perfect, as far as being the same size on each side, at the seam, as I have ever seen. I

pondered the wisdom of only one joiner, until I realized that the main flying stress, on a

twin, is carried on the wings..The engines!! There is relatively little stress on the center

joint as compared to a single engine plane. On a single engine plane, the weight of the

engine is transmitted into the center of the wing at the fuse to wing joint. Not so on a twin

with the engines on the wings. The fuse is relatively light, and so puts little stress on the

wing joint. Further inspection showed that the leading edge and trailing edge of the wing is

spruce and not balsa, as is so many ARF's. This further increased my confidence in the

design. The firewalls were already fuel proofed with some type of gray paint on both sides

of the plywood. I felt that better safe than sorry, so I sloped my usual generous supply of

30 minute epoxy, just for good measure. Next the supplied engine mounts were installed

loosely to the engines, to get firewall to engine nacelle clearance and spacing. I am using

the Magnum 52 four strokes, so the engines needed to be spaced as far back as possible.

This is necessary to keep the back plate of the spinner at the proper projection from the

engine nacelles. This rearward position really created a headache for the throttle linkage.

More on that later. The required hardware was packed with the mounts. The supplied

mounting hardware for the separate arms of the engine mounts, is simply bolts and normal

' nuts and washers, of which I loctited with "The blue stuff". One point to be aware of, is

the width of the four stroke engines mounted upside down, made the spacing of the

mounts so wide that I had to grind a bit of the triangle stock from the back side of the fire

wall to get the nuts, washers, and lockwashers on. Probably not a problem with upright

two stroke engines. The fuel tanks are mounted at this time. The tanks are not marked as

to size, but I would venture a guess of 6 ounces. The outlet construction is the normal two

ports for inlet and outlet. There is a third outlet at the top of the tank for a vent to the

muffler and was already open. Normally, I use the curved tube inside the tank for this,but

saw no harm in using the supplied molded vent. You will note that the tank is impossible

to mount upside down, due to this vent outlet going through the firewall. Here you do not

want to mount the tank tubes as pictured or you will have no muffler pressure. It shows in

the series of pictures that the extra tube from the tank is for filling. You cannot reach it

unless you let it hang out and plug it after filling. The kit does not include a large sheet of

1/4" foam that must be cut to form a seal at the tank neck through the firewall, as well as

supply a cushion around the tank. Here would be a good place to note that building tip in

some type of written instructions. The pictures show mounting the tail cone of the engine

nacelles at this time. I would suggest not to mount it until the engine controls are finally

installed and adjusted, to prevent damage. The engine nacelles are fit up and cutouts

made for the engine. Note the picture on the box for the "Bump" of the engine

supercharger to be properly place up. I would point out that these nacelles are some type

of PVC as in most kits, but these are already reinforced with fiberglass mat. I'm impressed!

Impressed until I started grinding them for the engine head projections and the dust flew

everywhere (Wife did not catch me until I was out of the house!) The rails for the throttle

servo and landing gear mounts are already in the engine nacelles. If you opt not to use the

hard wood mounts and go with air retracts, the mounting rails are already installed. In fact

the supplied fixed gear must be mounted into adapter blocks (Supplied) for the main and

nose gear. If you are using retractable landing gear or fixed, cut out the openings in the

bottom of the nacelle cover before installation. (Not covered in the picture instructions.)

The pictures show that the covers are to be screwed in, with the supplied screws, and

secured with C.A. I chose to use Plumbers "GOOP" as I might some day want or need to

service the landing gear. You could also use silicon sealant. The passages for the wiring

for the aileron and throttle servos were prerouted with string for easy installation of the

wires. You need two "Y" cords for the ailerons and throttles for standard installation.

Mounting the Tail Feathers

Take the inserted areas of the elevator halves and the bottom of the rudder. Cut off

approximately 3/16" of the covering, to make a good glue joint.The elevator halves are

slide into each side of the fuselage and the rudder slide into the top. When the elevator is

in place the dihedral of the elevator halves is set...sort of. Make sure the fuse is held down

and level before beginning this procedure. After inserting the rudder, and before the epoxy

sets, measure that the elevator halves are equal height from the table so that each surface

is at the same angle, and that the rudder tip is the same distance from the elevator tips.

Control Mounting

The control horns are mounted next. The good news if that there is no problem to find the

correct hardware to mount the control horns..The required screws are right in the package

with the horns. The bad news .Not one of the machine screws is long enough to reach

through the elevator or rudder, and forget about the length required for the built up

ailerons...Almost 1.5 inches. Substituting 6-52 screw and all thread worked fine.....Until one

of the premounted elevator halves fell off in my hand...Not a confidence builder!! The other

control surfaces seemed strong enough, but I used small wood screws and epoxy on all of

the hinged area to be sure. I painted them black to not be obtrusive. When mounting the

aileron servos, I again had one of the preinstalled rails for the aileron servo come off. I

pulled the other servo mounting rails off of the servo covers and re-epoxied them all and

added triangle stock to be sure. If you plan to use pneumatic retract mechanism, now is

the time to install the air tank under the push rods for the rudder and elevator. There is

already a circular cut out for the tank in the fuselage. Be sure to install the airline to the

tank, as it is difficult to access with the reach rods in place. The supplied push rods

seemed a little light for my taste for the elevator and rudder control on a powerful twin

engine plane. I substituted 4-40 rods inside of the preinstalled outer covering for the push

pull push rods. This is my personal feeling, the supplied rods may have been fine, but for

me better to change if any question on a fast plane. The mechanical joiner for the two

elevator halves is supplied, and I drilled out to accommodate my 4-40 rods. I maintained

the 2-56 for the connection to the high torque elevator servo. The rudder connection I also

used a 4-40 rod to a standard servo. Even the connectors for the reach rods, at the servo

arms, was furnished and of good quality.

Engine Control Installation

As I chose to install Magnum 52 four stokes inverted, the engines must be mounted as far

back as possible to get realistic prop clearance. This poses a real problem with the reach

rod installation. There is no room to install a normal clevis due to the closeness of the

firewall. Simply installing a loop from above to the reach rod was not normal, as the loop

hit the cylinder head and to make is short enough to follow the arc of the control arm on

the carb caused binding from closed to open. My solution was to run a metal push rod (

Furnished in the Kit) from the servo (which is not accessible after the nacelle covers are

installed) formed into a 3/8" loop, to a slip type connector on the throttle control arm on

the carb so that small adjustments for equal engine operation was possible. I put the

plastic push pull rod, that I previously rejected over the rod, and ran the whole mess

though an outside covering for the plastic rod and through the fire wall. The covering was

run 6" inches into the nacelle to prevent fuel from coming into the nacelle. This loose fit at

the fire wall allowed the rod to move up and down without binding. I also installed the

McDaniels on board glow drivers, for twin glow plugs, for the inverted four stroke engines,

for safe starting and increased reliability.

Canopy Installation

The instructions say to install the various canopies at this time. I waited until the retract

system was installed. This to prevent damage to the clear canopies. The instructions again

indicate, to mount with CA. I used "Goop"

Retract Installation

I used the Spring Air System for this project. Note, these are not supplied with the kit. The

structure is already set up for pneumatic retract systems. As previously stated, the kit

contains the adapter blocks and pictures, to install the included rigid mounts, but the

under covers and frame work is already done for retracts.The retract manufacture's

instructions should be followed for connection, but there is a pretty self evident set of

pictures in the instructions as to how to mount and plumb the air system and install the

retracts. They leave out how to connect the steering gear to the rudder servo.

Control Throws

Learn to fly with the rudder or leave twins alone!!!! I set the recommended throws at 1/2"

for the ailerons and elevator. I did not agree with only 3/4" rudder throw, to keep me out of

trouble in the event of engine failure, I want all of the rudder control I can get. I set it to 1"

each way, which is all that is possible due to rudder interference with elevator.

Gyro Installation

While not necessary, I am into insurance wherever possible. I chose to install two gyros in

this plane to make sure of sufficient time to react in the event of engine failure. I installed

the Hobbico Multipurpose gyro on the rudder and set for 50 % gain. The Hobbico Areo

Gyro was installed on the ailerons and connected to a separate channel's rotary dial, on

the transmitter, for gain control from the ground. Starting point was 50 % gain. If the

plane's wings start "bouncing" up and down, the gain, for the aileron's gyro, can be

reduced as needed. If an engine fails, the plane's reaction is a quick yaw into a snap roll.

The slower the airspeed and higher the power, the faster the snap roll will occur. The gyros

dampen the action enough to be controllable and save not only your nerves, but the plane

as well. Additionally, the manuvers are very crisp and landing is a breese.

Wing Installation

Slide the wing onto the fuselage, and secure with the two supplied nylon bolts. The plastic

cover over the wing and on the fuselage cut out for the wing, has cut outs for the wing

hold down bolts. They are accessed by removing the plastic covering over the precut

holes. Once the prefabricated cover, over the wing, is installed, the wing bolts get a bit

difficult to access as they are inside of the cover by one inch. A tube for access would

have helped at this point.

Now install the various canopies, plastic nacelles, and decals that come with the kit!!! The

plastic

nacelle covers that come with the kit are secured via wood screws into the wing sheeting. I

found that the plywood formers needed to be trimmed down so that the plastic

covers,behind the engines, would fit flush with the wing surfaces. If you want to add a little

additional scale "Guns", they can be fabricated out of 1/8" dowel rods painted black and

glued in place. You can either paint the "glass" nose windows black, or make out of balsa.

I found that the batteries had to be put into the nose for proper balance. This requires a

long drill to get through the front landing gear bay.

TIME TO GO FLY!!!!!!

A Few Twin Flying Tips

Twins are no more difficult to fly than single engine planes. They typically feel "Heavier"

due to higher wing loading, but control is similar. I do not subscribe to the widely held

view that the remaining engine, on a twin, gets you to the crash site sooner. It is just not

true!

Rule number one. Always have a copilot to handle a twin. There is a lot of flying propellers

and less places to safely handle a twin.

Rule number two. Always start the engine farthest away from you and get it set, before

starting the engine nearest you. You do not want to be reaching across a running engine

to start or adjust another engine.

Rule number three. Reliability is the single most important aspect of flying a twin. Set the

engines a little rich. Match the strong engine to the weaker engine..Never the other way

around. Always ALWAYS!!! Bring the engines to full power and hold the plane straight up

for 6-8 seconds. Any sign of a sagging engine means trouble. Correct it now and do not

take off until the engines pass this test without a significant loss of RPM. Loss of an

engine, on take off, is death to a twin!! A fast snap roll, and it is over.

Rule number four. If you lose an engine, gyro or no gyro, the plane will begin to yaw, and

raise the wing on the good engine. Throttle back...NOW! Lower the nose, to keep airspeed,

and so control up, and make immediate plans to land. You can fly on one engine as long

as the airspeed is up and the air is going over the control surfaces, but a snap roll is just a

heart beat away, if the remaining engine is much over 60% power. Turning away from the

running engine is inviting a snap roll. Throttle back, and turn toward the good engine.

Once the new course is established, slowly bring the throttle back up to a maximum of

50% power. Here less is better! The idea is not to continue to fly, but to get into a safe

landing position. Once on final approach, chop the throttle and land. Never bring up the

throttle on the remaining engine on final approach. The plane will roll over into the ground

quickly.

Rule number five. If you don't currently know what the left hand is for, the rudder, it is

extremely difficult to handle a twin with an engine out. The rudder is very important to

control a plane that is trying to yaw away from the running engine. The ailerons alone

cannot handle single engine operation. Learn to fly using the rudder!!

The above discussion is intended for beginner twin pilots. I realize that multi-engine

planes can be flown with one engine and loops and rolls are possible. I have even taken off

with one engine, but this is not for the beginner, and should not be attempted until much

time is spent in the company of multi- engine planes,and their control.

Flying the A-26

The final part of any model is flight. The day arrived to actually fly the plane. Note, the

actual plane used for the flight was powered with two Thunder Tiger .36 engines using

APC 9x6 two blade props. Two type of flight tests were performed. One with the gyros and

one without. The engines were properly broken in, brought to full power using

powermaster 15% fuel. The plane was held straight up by my co-pilot and engine stability

checked. Minor readjustment was necessary at this point to assure engine stability and

reliability.

The plane accelerates like a rocket. The rudder is very responsive to input on take off. A

little exponential would be good at this point on the rudder. If the gyro is used, rudder

control on take off is almost a non-issue, as long as the engines come up together. At take

off speed the plane lifted right off and only required two clicks on the elevator for landing

gear changes, and one on the ailerons.

In Flight

The plane will fly very well at approximately one half throttle. Loops were large and stable,

with or without the gyros. The plane has no flaps, and does not need them. A nose high

approach is very controllable and smooth. If the gyros are used, the landing is engines and

elevator. The wing loading is heavier than pattern ships and trainers and so landing and

pattern manuvers are at higher speeds. Rolls are smooth. The twin gyros on will really

make four point rolls crisp. Ok Ok so it is not a patterm ship, but we need a little fun. The

plane flys with up trim needed on the elevator until the gear is retracted. At that point, the

elevator trim is almost neutral. A computer radio is helpful at this point to program a mix to

change the elevator trim for up and down landing gear.

Single engine operation

Naturally, during the testing one engine died....Ok so I violated rule number one of always

doing the vertical test and the temperature changed. With the gyros off, the plane tried to

yaw into the dead engine. Rudder and ailerons were added to correct. The remaining

engine was brought to approx 15% power and a turn into the running engine was

performed.The power was brought back up to approx. 75% after the turn, and the nose

pointed down for the landing. No attempt was made to fly the model on one engine, due to

deadline on this story and lack of guts on as yet unfamiliar model. From past experience,

the gyros would have made the engine out easier to handle at the surprise outage, but the

plane flew well on one. Note, the pilot is an experienced twin flyer. Single engine operation,

on any twin, is not recommended.

Summery

All in all a very good flying model with no notable bad flight characteristics. Looks

fantastic in the air and on the ground. The rudder is very responsive and needs to be for a

twin. One problem is with the covering. In direct sunlight, it begins to wrinkle quickly. For

the most part it goes away as it cools. This covering will not lend itself to repairs. The nose

art on this model was provided by the owner of the model who actually flew the A-26 in

Korea.

Finished model

ready for flight.

This is the nose art of the

owners actual plane from

Korea War. Mr. Jim Rose, of

Houston Texas, was in the

90th Squadron 3rd bomb

wing.

General layout

of all the parts

before assembly

The Hobbico Aero Gyro is

installed on the wing with

double sided tape.This gyro

is used to assist control of

the ailerons and hold the

wings level in the event of

engine failure. Note, I used

two channels for the

ailerons.This gyro is

specifically designed for

that.

The inside of the fuselage.

The push rods shown are

already installed in the

plane. The hardware already

has the connector for the

double output to the

elevators. If you look

closely, you can see to the

left of the picture the

Hobbico Multipurpose gyro

for the rudder to minimize

yaw in the event of engine

failure.

This is a shot of the wing

being attached to the

fuselage, There is quite a

"Rats Nest" of wiring in a

twin. Remember that there

are servos for the engines,

air lines for the retracts,

aleron wiring, ect.

You can read more of TwinMan's advice on his Advisor Page or on the Techniques Page