The DB Models Spitfire is a scale model of wooden structure with veneered foam wings.
The wingspan is 78 inches and it requires a 25cc - 35cc 2-stroke engine and four to six function radio.
The weight should be between 20 and 30lb.
The plans as supplied show the full fuselage and tail structure while the partly pre-assembled foam wing panels require only diagrams. There is an excellent instruction sheet.
The quality of the foam wing panels and the glassfibre moulded engine cowling is excellent, while the standard of wood is high with accurately cut ply parts. A vacuum-formed
cockpit canopy and spun aluminium spinner are included.
Structure
The fuselage is built as a sheet balsa box, with curved balsa sheet upper deckings and balsa block underneath. The engine is radially mounted inverted under a glassfibre cowling. The spinner has a long nut which is designed
to screw onto the engine crankshaft at one end while taking a bolt throught the nose of the spinner at the other end. This nut comes threaded for the spinner bolt at the front, but is left with a plain hole at the other end. The builder has to enlarge this
hole and tap a thread to match the crankshaft thread on the chosen engine. It helps to have friends in the engineering business!
Large wing root fillets are formed from thin ply which fit well for the most part, although I found it better to replace the portion which covers the front third of the wing root with block balsa.
The wings are a bit more complicated than the average foam panels as only the underside comes ready skinned with balsa sheet. Due to the difficulty of reproducing the Spitfire's elliptical wing with it's compound taper in chord and thickness
the builder has to carefully carve away some of the polystyrene foam from the top surface, then skin the result with 1/8 inch balsa sheet, using a foam-friendly adhesive. The instructions are very helpful and cross-section shapes are provided for checking progress. The process is
a lot simpler than it sounds and the result is a better looking wing than found in most Spitfire kits. You also end up with a workshop covered in polystyrene foam beads. After the wings have been skinned the balsa leading and trailing edges may be added in the usual way. Ailerons have to be cut out of the wing panels and finished,
along with flaps if required.
No undercarriage components are supplied, as the manufacturers expect you to choose and fit a retract set. Fitting such units is a straightforward job, but care must be taken to provide a mounting plate of large surface area bonded securely into the wing.
The wing is built in three panels which are then permanently joined with epoxy resin, the joints being reinforced with glasscloth tape. Wingtips are laminated from a thin ply core with thick balsa sheet above and below. These are a weak point and need to be firmly secured to the wing panels,
preferably with glass cloth and resin over the joint.
The lower centre section attaches to the fuselage with dowels and nylon wing bolts. Given the size, weight and manoeuverability of this model, I replaced the bolts with steel ones.
The tailplane and fin are built as flat balsa frames which are shaped to section then skinned with balsa sheet, while the elevators and rudder have half-ribs applied over a 1/8 inch balsa sheet core.
Doped nylon covering is used on the open-structure tail parts. More modern heat-shrink covering materials may be used instead. The rest of the model is treated with
sanding sealer then tissue covered, or you could use epoxy resin and fine glass cloth.
There is more than sufficient space for the radio installation. The rudder is driven by closed-loop cables,
the rudder horn being linked directly to the servo,
while the elevator has a hard balsa pushrod to the servo. On this type of model I would recommend a high-power servo on the elevators.
The aileron and flap servos fit in cutouts in the outer wing panels close to the control surfaces using long extension leads. Actuation of the
undercarriage will depend on whether a mechanical or pneumatic retracting system is employed.
Flying the model
This is a fast but stable model. Provided the centre of gravity is in the right place (assisted by a substantial chunk of lead as far forward as possible!) it is very pleasant to fly.
Take-off needs to be held straight by careful use of rudder as the narrow undercarriage will tip it easily onto a wingtip. Acceleration is initially slow if you have an engine at the smaller end of the range,
but once the wheels are up it accelerates quickly and the climb is brisk. Simple aerobatics are straightforward, with all the basic manoeuvres being possible.
The model has a fast and flat glide and really benefits from the addition of flaps to steepen the approach. As with the take off, the landing needs to be carefully done so as not to tip it sideways onto a wingtip. Altogether a fine flying model which really looks the part in the air.
Structural assessment
The Spitfire is a metal skinned aeroplane with some fabric on the control surfaces, so the choice of balsa sheet and veneered foam wings is consistent with the desired surface appearance. The design is well thought out
and has only a couple of weak points. The undercarriage is a potential source of problems as polystyrene foam is not the ideal material to attach it to. Mine has come loose on several occasions. The wing tips are the other weak point. Unless they are firmly secured with glass cloth tape and resin
they have the potential to break off. The narrow track undercarriage does not help, and landing damage on the wingtips is common. The biggest problem with the wingtips is if one touches the ground during takeoff, or if previous landing damage has not been spotted and rectified. The loss of a single
wingtip in flight leads to difficulties with the subsequent landing, with the affected wing being subject to vicious tip stalling. The only sure way of eliminating this hazard is to build the model as a clipped-wing mark 5, which also lets your model stand out when flying with a group of six or more similar models!
The only area for potential weight saving is in the elevators and rudder, which could be made as built-up units without the balsa cores. This would have the advantage of reducing the lead at the front a little too.
How scale is it?
Comparing the shape of the model with a good scale drawing and with photographs of the full-size, the fuselage outline appears to be commendably accurate. The wings however
appear to be a little short on span. It would be possible to add a bit of extra foam to the wing roots before skinning the panels but care would need to be taken to ensure structural integrity in this vital area.
The only compromise is in the wing centre section, which is flat rather than having the inverted gull-wing appearance of the full-size at the trailing edge, but this detracts very little from the overall appearance.
A very good point is that the ailerons are proper Frise units, and the tail surface hinge lines are partially faired over, improving the appearance.
With careful work and attention to the small details this will make an excellent scale model, not just a lookalike. There is space to do a really good job of the cockpit and much scope for panel detailing on the surface.
An inventive builder should be able to produce an exhaust system which fits entirely within the engine cowling.
Colour schemes
The Spitfire enjoyed a long career with the pre-war Royal Air Force, all through world war 2 and with a variety of air forces and even civilian use post-war. Thus there are a massive variety of colour schemes to choose from. There are many examples still
flying and lots more available for study in museums worldwide. A little research is bound to turn up a good colour scheme. This model may be built as a mk.1, mk.2 or mk.5 with little modification. A mk.8 or mk.9 would need the cowling replaced by a longer version, with the engine mounted further forward.
Griffon-engined variants would need extensive modifications to the nose and the tail surface shapes.
Early Seafires and photographic reconnaissance versions or even the original prototype K5054 could be made from this kit too.
Detailed photo sets of full-size Spitfires are now available in our MartinPhotos section:
Click on a picture for further information
Spitfire Mk.1a N3200
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Spitfire Mk.1 P9374
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Spitfire Mk.1 R9612
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Spitfire Mk.1a AR213
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Spitfire Mk.IIa P7350
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Spitfire Mk.Vb BM597
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Spitfire Mk.Vb EP120
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Spitfire Mk.VIII MT928
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Spitfire Mk.IX PL344
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Spitfire Mk.IX MH434
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Spitfire Mk.XIV MT847 Set 1
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Spitfire Mk.XIV MT847 Set 2
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Spitfire Mk.XVI RW393
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Spitfire LF XVIe TD248
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Spitfire XVIII SM845
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Spitfire PR XIX PS890
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Spitfire Mk.24 VN485
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Final verdict
This model is not difficult for an experienced modeller to build although there is a lot of work in it. It will benefit from careful research and application of detail which will give you an excellent flying scale model of the world's finest aeroplane.
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