Engineering the Magic of Flight – from F3K precision to electric and rocket-powered concepts
Engineering Rooted in Research
Every Ston Model glider is the result of long-term aerodynamic research – not theoretical design alone, but hands-on field experimentation and begins with structural precision.
Two-piece wing and tails use solid PMI core construction, ensuring exceptional stiffness-to-weight ratio and long-term structural stability.
The composite layout is based on carbon IMS65.
We produce our own spread-tow fabrics from original IMS65 roving. For the fuselages, we developed a proprietary woven structure – also based on IMS65 – optimized for torsional rigidity and control flex behavior.
This allows:
- Extremely light yet stiff structures
- Precise energy transfer during launch
- Long-term durability under competition stress
Technology, for us, begins in the material itself.
The Research Behind Wizard
The story began with a simple but critical observation:
Why do the small gliders stall earlier and feel less predictable than large ones?
Years of flying 3.50 and 4m F5J and F3J models revealed something unexpected when transitioning to 1.5m F3K aircraft – aggressive tip stalls during tight thermal turns.
That question launched a deep aerodynamic investigation.
The Problem
Small gliders are extremely sensitive to airflow disturbances. During tight thermal turns, strong vortices form at the ends of the ailerons. These vortices increase induced drag and disturb airflow over the wing – leading to premature stalls and unpredictable behavior.
The Solution
After extensive airfield testing and structural experimentation, a practical aerodynamic solution emerged: a distinct triangular shaping at the end of the ailerons. This innovation reduces harmful vortex influence while maintaining reasonable production complexity.
The Wizard Project – Where It Began
The Wizard project was never meant to be just another model. It began as a research instrument – a platform to study induced drag and improve large glider performance.
Small gliders were chosen precisely because they ex aggregate aerodynamic imperfections. They reveal weaknesses immediately.
Through continuous experimentation, the Wizard was born.
Its flight properties:
- Smooth thermal turns
- Absence of sudden stalls
- Efficiency similar to larger aircraft
“Curiosity leads to the continuous search for improvement. And this is one infinite magical process.”
– Stoycho Nikolaev, April 2024
The Triangular Aileron End
This innovation became one of the defining aerodynamic signatures of Wizard – and later Shaman. It allows the aircraft to retain energy during turns and maintain smoother airflow across the wing surface.
- Reduced unexpected stalls
- Improved roll control
- Better energy retention in thermal turns
- Smoother thermal turns
- Flight behavior closer to larger-span gliders
Wizard proved that small gliders could feel “big” in the air.
Why Move Beyond Wizard?
After seeing the aerodynamic advantages of Wizard, a new ambition emerged:
If Wizard solved stall problem… could we create an almost ideal F3K model?
Shaman
Shaman was not a cosmetic evolution. It was a full aerodynamic refinement.
Key developments:
- A new thinner wing airfoil calculated and developed by Stoycho Nikolaev, founder of Ston Models
- Preservation of the triangular aileron tip – now a defining signature
- Completely new fuselage
The fuselage retained the curved “banana” silhouette introduce in Wizard. This shape originates from my earlier aerodynamic work during the development of the all Explorer F5J series.
However, in Shaman we have:
- Two-piece top-mounted wing secured with joiner and four screws
- Proven dihedral-style elevator inherited from Wizard
- Structural balance between performance and durability
- Updated rudder geometry for improved control authority
- Spring-contact wing-fuselage electrical connection
The result was a cleaner airflow interaction, stronger mid-structure and more precise handling
Shaman became sharper, more efficient and competition-ready.
The Birth of Shaman 2 – Why Evolve Again?
Shaman was extremely stable.
Perhaps too stable.
Extensive real-world resting revealed something unexpected:
We wanted it to feel more alive. More agile.
After prolonged testing:
- The front fuselage was shortened by approximately 3cm
- The elevator incidence angle was slightly modified
- Elevator area increased by 10%
- Nose cone reshaping improved launching
- The fuselage structure was reinforced to carry up to 150g ballast in wind conditions
- The agility increased
The transformation changed the character of the model.
Thus, Shaman 2 was born.
More responsive.
More dynamic.
Still predictable.
Shaman EVO
Inspired by Slope Energy
The idea for Shaman Evo came from high-speed slope flying with extremely tight turns.
It uses the same Shaman wings, but the fuselage is completely different.
Key differences:
- Two-flap elevator controlled with two servos
- The elevator is mounted under the fuselage
- Total 5-servo configuration
Shaman Evo is sharper and more aggressive, designed for pilots who demand immediate response and tight-radius performance.
Where Shaman 2 balances stability and agility.
Shaman Evo pushes agility further.
Electric Adaptation – F5K Shaman
The F5K Shaman uses standard Shaman wings combined with e dedicated electric fuselage.
Electric flight introduces new load patterns, vibration forces and climb energy dynamics.
To support this:
- A specialized electric fuselage was developed
- Custom carbon propeller blades were designed in-house
- A proprietary carbon spinner was created
The result preserves Shaman’s glide efficiency while optimizing climb performance and structural reliability.
For hobby pilots, it means accessibility.
For competitors, it means efficiency without compromise.
Shaman S – Rocket Glider Concept
Shaman S was developed by request of the Bulgarian National Rocket Modeling Team, class S8.
The wing originates from the Shaman platform, shortened and bonded in a dedicated mold to achieve the required geometry.
The fuselage is completely straight – specifically engineered for rocket-assisted launch.
Additional developments include:
- A dedicated carbon motor holder
- Reinforced structural alignment for high acceleration loads
Shaman S must withstand extreme launch forces and immediately transition into efficient glide.
It represents a different energy philosophy – but the same aerodynamic foundation.
Wings that Unite the Family
Shaman 2 and Shaman Evo are fully compatible with the original Shaman wing system.
No matter which fuselage configuration you choose, you benefit from the proven aerodynamic excellence of the Shaman wing platform
One aerodynamic foundation.
Multiple performance philosophies.
Engineering Meets Evolution
From Wizard to Shaman
From stability to agility.
From hand-launch to electric and rocket propulsion.
Each model exists because testing revealed something that could be improved.
Each evolution happened for a reason.
At Ston Models, design is not about creating more models.
It is about refining behavior in the air.
Performance is measured not only in numbers – but in trust, predictability and control.
Technology is never finished.
It evolves with every fight.