Ektron (oz16571)

About this Plan

Ektron. Radio control powered glider model. For electric power with brushless motor. Wingspan 2150 mm.

Quote (google-translated): "A nice electric glider for those who love long, relaxing thermal flights while staying with their noses up from dawn to dusk. Or almost. Ektron, by Mauro Capodaglio.

As the years passed and with the inevitable onset of senile ailments, I had to eliminate many things that were harmful to my physical and mental health, and consequently, I also made drastic choices when it came to model airplanes. Having definitely closed the aerotow-plane era with its 'science-fiction' developments, but firmly determined to fly in the fields behind my house without having to depend on anyone to gain my soaring altitude, the choice of electric gliders was the only possible one.

Another essential condition for me is being able to 'play' in complete safety, that is, using models of very small and light weight, made almost exclusively of balsa wood to minimize damage to property or people in the event of an accident.

I've always been disconcerted by certain displays I've seen with carbon fiber wings used as axes to demonstrate their resilience. This may seem strange to you, but I don't particularly enjoy the construction phase, and as the years go by, I spend less and less time at the workbench.

Paradoxically, I also have another major limitation: I can't fully enjoy myself if the model I'm playing with hasn't come out of my own hands. Don't get me wrong: I'm not a priori opposed to commercial models. In fact, when a friend asks me to test their 'rubber band' or ready-to-fly model, I'm often impressed by the performance, which is almost always excellent.

What still drives me to build is the bond that is created with the model during its construction, that bond made of an intimate knowledge of its strengths and weaknesses that, during flight, tells you how far you can push your pursuit of performance without resorting to sophisticated telemetry or futuristic composite structures.

The Ektron design was born from this philosophy and from the weight and power limitations envisaged by the Autonomy formula, a choice not dictated by competitive interest, but simply to provide more challenging rules for the game. The design I present to you, as I always like to point out, is simply intended to be a non-binding proposal, considering that everyone likes to make the modifications that best suit their own ideas and construction methods.

When designing the model, I tried to prioritize reliability, speed, and simplicity of construction without excessively penalizing performance. The high-tip wing is equipped with large flaps that, when used during landing, allow for a 50-60° glide angle and to center the model with millimeter precision. I did not use ailerons because, when flying small models at long range, I prefer to rely on the wing dihedral for stability rather than intervening with inappropriate corrections. The flaps only move downward, but I left a gap of about 1 mm to allow for a rotation of a couple of negative degrees in the event of needing to compensate for any twisting.

To simplify the construction of the wing, I use a custom plano-convex airfoil with a relative thickness of 8.7%, derived from the Selig 3021; it may not be the best aerodynamically, but it allows for the best reproducibility with the minimum amount of equipment. In this regard, I recommend always checking the consistency of the radius of the nose of the airfoil with a template if you do not want asymmetric stalls. Given the low taper ratio, the ribs can easily be made using the packaging method.

The D-box and ribs are made of 1.5 mm balsa, and the vertical baffles are also of the same thickness, which should be of decreasing hardness towards the ends. The spars are made of 3x5 pine in the outer panels, while in the central section they are..."

Direct submission to Outerzone.

Supplementary file notes

Article.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction