Svenson ‘Fly-Boy’ Plan Set 59” Span Sport aerobatic

Here is a reprinted plan made available from the archive of a collective of fellow aero-modelling enthusiasts. The archive contains older and hard to find RC and free flight model plans as well as rare, or out of production, kit plans.

 

A non-profit making service by aero-modellers for aero-modellers

 

The plan offered is a high quality print and does not fade in strong sunlight like the traditional dye-line prints used by the majority on plan suppliers in the past

 

THIS LISTING IS FOR A PLAN SET ONLY

YOU ARE NOT BIDDING FOR A KIT OR AN AIRFRAME

 

Here is the offer to bid on a reprinted set of restored kit plans for the Svenson ‘Fly-Boy’, which was a popular low wing sport aerobatic model that originates in the early to mid seventies. It was in production for a considerable length of time, but I believe it is now, along with the smaller ‘Mini-Boy, out of production.

 

Designed by Leon Janssens and kitted by Svenson of Belgium, the ‘Fly-Boy’ is a 1500mm (Approx. 59”) Low wing sport aerobatic model, with a semi-symmetrical wing section, intended for 0.35 – 60cu in 2-stroke motors. The Svenson ‘Fly-Boy’ was an ideal first low wing model when fitted with an engine in the lower end of the specified range, and a great sport model with any engine in the specified range, with optimum performance coming from models equipped with motors at the top end of the specified range. The model has pleasant handling and makes a great everyday sport model, or ‘improver’ model for those newcomers ready to move on from a high wing trainer.

 

The model features straightforward built up construction to provide a rugged airframe, well suited to club flying. The 3-sheet plan set is very nicely detailed, with full-size sketches for the wing ribs and all the fuselage formers (It even has a developed sketch for the rear turtle-deck sheeting that is fitted to the curved formers.

 

Sheet One (33” x 48” Approx) shows the fuselage construction and formers.

 

Sheet Two (33” x 47.5” Approx) shows the wing construction (both panels) and wing rib details + turtle deck sheeting.

 

Sheet Three (24” x 33” Approx) shows ‘3-view’ sketches of the various stages of construction of the airframe. A set of build instructions, reformatted from the original kit item is included.

 

If you are a ‘retro’ enthusiast, and appreciate a bit of traditional building, then this plan set offers you the opportunity to replicate the Svenson ‘Fly-Boy’, and personalise it to suit your own preferences and flying style. Even today, it remains a pleasant and very enjoyable sport model that is certainly not significantly disadvantaged by the age of the design, when compared to modern commercial offerings. This excellent design lends itself nicely to a little ‘modernisation’, which can enhance the performance envelope of this ‘classic retro’ machine. A great bit of nostalgia for modellers that have had, or flown, a ‘Fly-Boy’ in the past !

 

The recommended engine range on the plan is .35 to .60 cu in. You could fit 2 stroke, or the equivalent 4 stroke !  You may even wish to consider an electric conversion.

(This is certainly feasible with modern brushless motors & Li-Po batteries. For example, an AXI 4120/4130 brushless motor, turning a 12-14” x 6-8” APC-E propeller, running on 4S Li-Po batteries via a 60 amp ESC should equate to something equivalent to a 2-stroke motor around the middle of the specified engine range).

 

You are buying a plan set only – this is not  a kit or an airframe !

 

 

This is a traditional balsa & plywood build that provides a comparatively quick to build airframe.

 

The fuselage is a simple box structure, with curved decking to the top front & rear of the fuselage. The plan shows full details of all parts & formers (F1 – F11) for the fuselage construction. The dorsal, fin & rudder are all sheet construction. The stabilizer is built from strip wood and has a flat plate section, with elevators from sheet balsa shaped to a tapered section. The cowl is built up from balsa and ply.

 

The wings are  shown as two individual built up panels. Full details are given for the wing ribs (W1 – W5), and a sketch of the dihedral setting is shown. You will need to make a sketch for the dihedral braces/wing joiners, but that is quite simple to set out. The actual amount of dihedral is not critical to the flight performance on this design, it is largely there to prevent the wings from looking ‘droopy’. The wing is shown as a ‘bolted on’ item, but you could readily adapt it to be fixed with rubber-bands if you wanted a bit more ‘crash resistance’, or preferred it for operation on rougher grass strips.  The built up ailerons are ‘inset’ and are shown operated by outboard bell-cranks driven by a centrally positioned servo.

 

The model is a traditional ‘tail-dragger’ with the fixed undercarriage mounted to the wing via hardwood blocks. There is not a sketch for the undercarriage legs, but there is sufficient information to interpolate the necessary details for them. You may wish to substitute commercial items for the undercarriage (which may need some slight adaptations to the wing structure).

 

 

The Svenson ‘Fly-Boy’ built as shown on the plan has 4 channel Aileron/Rudder/Elevator and throttle (or ESC ! ) controls. You may wish to follow the popular current trend of fitting one servo in each wing panel to provide a direct link to the aileron and enable a crisper response, with the opportunity to experiment with aileron differential settings and flaps when using a computerised transmitter.

 

With the exception of the cockpit canopy, this design does not require any special, or custom made, parts, so all necessary items should be readily available from your local model shop. You may be able to source a suitable canopy from trade suppliers (Such as ‘Vortex Plastics’), or form your own by remoulding a large plastic drinks bottle over a hardwood former. You could use alternative materials, such as carved foam skinned in epoxy glass-cloth (or brown paper & thinned PVA adhesive). A further option would be a slight remodelling, with an open-cockpit and simple wrap-round windscreen.

 

The plan clearly shows the position for the centre of gravity, and includes some recommendations for the travel of the control surfaces.

 

The build is straightforward and would not present any problems to an experienced kit builder. It would even suit a novice plan builder. The model could even be used as a ‘low-wing’ trainer if set up on reduced throws and used with a “buddy box” system and competent instructor.

 

Here is the chance to build a replica of the Svenson ‘Fly-Boy’ at a price much less than that of a comparable kit.       More work … but more satisfaction !

 

Bidding starts at £12.50 for this 3-sheet plan set & build instructions.

 

P&P / Delivery within UK via 1^st Class Royal Mail will be £2.00 with plan supplied folded in large envelope – approx A4 size.

 

Happy to post overseas – Cost by Air Mail will be £3.00