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Spitfire IX plans are available from: Airborne Plans Service for AU$45.00 (2 sheets) plus P&H2 (AU$2.80
within Australia)
The design of this model is for the average modeller to be able to build a good sport scale Spitfire with a relatively simple structure. The construction of this Spitfire is no more difficult than a basic trainer model utilising flat tail surfaces from 9.5mm balsa, flat sheet balsa fuselage sides with rounded top and bottom and carved strip balsa ailerons. This model is designed as a semi-scale with the ability to be used a weekend flyer. The Spitfire fits easily in the average car and can be assembled in a few minutes. CONSTRUCTION Wings
Start by pinning down the spruce spars and then glue the ply and balsa ribs and dihedral brace together for the wing centre section. Glue the rear spar in place, then remove from the plan when it is dry. Now using the same methods as previously, frame up both the outer wing panels over the plan. When completed, pack up the washout in the outer wing as specified and join to the centre-section at the correct dihedral. Add the leading and trailing edges now as well as the centre-section sheeting. While the panel was still on the building board, I sheeted and capstripped the wing to maintain the washout and avoid possible warps. The undercarriage blocks should be epoxied into place before the lower sheeting is added. After the sheeting is finished, a plywood plate is added to the lower trailing edge of the wing mounting bolts.
Next mount your aileron servos where the plan indicates and then sheet around them. The wing tips can now be added and then carved into shape. Sand and finish the wing, adding the radiators and air scoop and then the wing is ready to cover. I used Koverall on the wing, tail surfaces and the fuselage. Tailplane, Elevators, Fin and Rudder
Sand and shape all these parts to the plan. Be careful to keep all tail parts as light as possible to decrease the amount of nose weight needed to balance the model. Fuselage
Next glue F1, F2, F3and F4 to one side making sure they are all square. Then glue the sides together and add the remainder of the fuselage formers. After checking the alignment of the fuse, add the stringers to the front turtle deck then sheet with 3mm balsa. You may find it helpful to wet the balsa with ammonia and water to assist in shaping the wood easily. Next I fitted the finished wing to the fuselage, then drilled the holes for the 6.5mm dowells to the front of the wing through the former for best accuracy.
When the wing is attached and true to the fuseleage, the tailplane and fin can be added. Check the incidence of the tailplane and its alignment before gluing. The fin can now be added followed by the carved blocks. Next add the rear turtle deck using tow sheets joined at the top. Bottom sheeting can now be added.
Finishing
For the finishing coats I used enamel with a catalyst and a matting agent to give a scale-type finish. The finish I chose is based on 91 Squadron, Ludham, Norfolk in the spring of 1945. I used a 200ml fuel tank and a J Tec pitts type muffler. Standard servos could be used safely through the entire model but I chose to use JR511 servos for all the flying surfaces. Dry weight was 3.8kgs with lead necessary to balance the model. Balance can be achieved by judicial positioning of the radio gear, particularly the battery. Flying
I was apprehensive about the typical Spitfire tip stalls but I had no problems with this model.
SPECIFICATIONS Spitfire IXType: R/C Sport/Scale Plane Spitfire IX plans are available from: Plan No. 666 Moulded Canopy: AU$27.00 plus AU$6.00 postage To return to Airbornes
home page This page was last modified on the 21-May-02 |
It is
62 years since the first prototype flight in March 1936 of the
world famous Spitfire. This remarkable aeroplane is almost
immediately associated with the Battle of Britain, making the
Spitfire one of the most modelled aeroplanes ever built.
I
decided to build the wing in three parts due to the polyhedral
shape of the wing, beginning with the centre section and then the
outer panels.
To
simplify the strip aileron construction I tack glued them in
place, after laminating sheet balsa, then carved them to shape on
the wing.
The
tailplane and rudder are built up from 9.5mm balsa which is
straightforward and strong. First cut out all the relevant
pieces, then build directly over the plan, making sure you cover
the plan with glad wrap or waxed paper.
Begin
by putting the fuselage doublers and the 3mm x 6.5mm stringers on
the fuse sides making sure you have a left and right side.
Once
the wing is mounted at the front, the alignment to the fuselage
must be checked before adding the rear bolts.
Mounting
the engine was my next move, using a round piece of 3mm ply for
the 2 degree offset sanded to wedge shape on the ply. I used a
nylon radial mount in conjunction with my ever reliable O.S. 61 FSR. After fitting the motor the remainder of the cowl was carved
from 12mm balsa blocks. Add the wing fairings now by laminating
balsa together then attach the wing. Cover the area with glad
wrap then glue the fillets on the fuselage with the wing in
place. Sand and finish to prepare for covering.
After
covering the entire model with Koverall, I primed the airframe
with automotive acrylic primer surfacer to give good adhesion for
the colour.
Unfortunately
the grass on my flying field was very thick with clover and
increased the tendency for the model to nose over when power was
applied. Also a gentle crosswind caused the model with its narrow
undercarriage track to weather vane. Once the model had some
speed it tracked well and the take off was very smooth. Only
minor trimming was necessary to gain straight and level flight.
Next I gained some height and checked the model's reaction to the
stall.
This
was gentle and predictable and coupled with the elevator
sensitivity showed the balance point to be accurate. At full
power the model is quite fast and is capable of nice scale rolls,
loops, immelman and stall turns. Knife edge attempts were poor
due to the small rudder size and the amount of movement
available. Good recovery was possible from spins and snap rolls
but some speed is necessary because when the model slows down too
much in aerobatics therefore it recovers slowly. This model looks
best doing low flybys at 75% power, pity I didn't fit retracts.
The landing was predictable and best with a fast shallow
approach.
Overall
this model flies very well and looks like a true warbird without
the expense of a larger more complicated model. It is very easy
to fly and once you are used to the take off tendencies it is an
all round great flyer.