Micro-model

The micro-model is a leisure which is similar to models and dedicated to the design, manufacture and control of models very small. The most accomplished objects have a mass not exceeding a few grams and measure only a few centimeters in length. Often, micro-models are the objects that can fit in one hand and have a motor system that allows them to move independently. Micro-modeling is therefore distinguished in this sense models , which remain static.

Unlike the models, whose goal is to reproduce as faithfully as possible all the details of an object (usually a means of transport) without it being able to move by its own means (with the exception of the model boats) , micro-modeling emphasizes the actual operation of the device.

Control modes

There are usually three types of control:

  • Wired link control;
  • The remote infrared;
  • The radio remote control, or radio remote control .

The wired command

The device is connected to its control device by a wired connection (wire guidance). This mode of control tends to disappear more and more, because the presence of the thread prevents the realization of many figures.

Made according to a model plan for rubber engine, smaller dimensions, wingspan 22 cm , infrared remote control three ways (we notice the depth flap).

The infrared remote control

This mode of remote control is particular to the interior flight ( indoor ) and the reach can reach the length of a gymnasium ( 30 m ), which is largely sufficient for a micro-plane of 3 g and 15 cm of wingspan (limit visibility).

Square 5.5 , micro-aircraft below 2 g, made according to a Billy Stiltner plan. Wingspan of 5.5 inches ( 14 cm ).
The infrared transmitter

Here is an amateur construction transmitter. It consists of an electronic circuit with a microcontroller , a joystick and a Li-Po battery of two elements:

The infrared receiver

This receiver is large enough to be made by a non-specialist. we will notice the microcontroller which is a PIC10F200. Most components are very easy to find in France, they are all CMS , whose advantage is the small size and the very reduced weight.

Implantation of the infrared receiver components for micro-aircraft.

The components are welded on the circuit, we will notice the infrared sensor on the left.

The receiver mounted on the model: it works!

The radio control

The radio remote control is by far the most sophisticated control mode and best suited to micro-modeling. It operates on a variety of frequencies , but it is necessary to ensure that no other micro-model or model reduces use the same frequency, otherwise conflicts may occur to create incidents or accidents.

Micro-modeling in aviation

Aviation micro-model is still called micro-aviation. Of all the disciplines of micro-modeling, it is micro-aviation that provides the most spectacular effects and the biggest “challenges”.

Blériot XI , “Channel crossing” type, 3.5 g , carbon and polystyrene construction , radio 868 MHz .
Renard R17 , according to B. delhalle’s “peanut” plan, wingspan 20 cm , weight 4 g .

There are three categories of micro-aviations:

Micro Helicopters

We find the replicas of the following helicopters 1 :

  • The Hughes 300 FAIRY Micro: a 2 axes which allows, by its microscopic size and flight stability, to evolve in the smallest spaces. The design is particularly successful;
  • Boeing CH-47 Chinook 2-Axis R / C Micro Helicopter : Pretty replica of the Boeing CH-47 Chinook. This micro-helicopter is a 2-axis (up / down, left / right). Its gyroscopic system in flight gives it a perfect stability;
  • Microhelicopter R / C 2 axis such Picoo Z : The smallest and lightest R / C helicopter in the world ( 17 cm long, weighing less than 10 g ). Helicopter very stable thanks to its new patented gyroscopic system;
  • Microhelicopter R / C 3 axes AMAZING MICRO 3D APACHE: A 3-axis (up / down, left / right rotation, translation forward / backward). This is a model mainly for indoor flights.

Micro-planes

Sorta MONO , after Martin Newell. Wingspan of 20 cm and weight of 5 g . Motor: DIDEL 4 mm , gearbox 5: 1 and battery: 20 mAH Li-Po. Radio: Plantraco 868 MHz , carbon ring construction.

We find the following aircraft 2 :

  • Micro Plane R / C twin- axle : With its 6.8 grams , it allows its microscopic size and slow flight to evolve in the smallest spaces. Virtually unbreakable, it is suitable for the youngest;
  • Micro plane ” Mini Bee Plane ” 2 axes : Twin-engine aircraft very lively. In indoor or outdoor flight without wind, it is able to evolve in the smallest spaces. 2-axis control by differential action of the two motors.

Mini-motorgliders

Mini- gliders are gliders equipped with an electric motor . They usually have sufficient spans to make it possible to shut down the engine at altitude and to continue the gliding flight 3 :

  • Mini 3-axis glider R / C glider: 107 cm wingspan, range of 300 meters ;
  • Mini Flyglider Easy fly R / C AIRPLANE 2 axes : 105 cm wingspan, range of 150 meters ;
  • Mini Humming R / C motorglider 2 axes: 94 cm wingspan, range of 150 meters ;
  • Orange R / C mini sailplane 2 axes: 155 cm wingspan, 500 meters range .

Micro-aircraft R / C scale “pistachio”

The “pistachio” scale (a plane whose wingspan does not exceed 20 cm , or 8 inches ) is an already known category in free flight with elastic propulsion. We have here to make models with electric propulsion and remote control in infrared.

This BD4 pistachio scale has a wingspan of 20 cm for a weight weight of 4 g . It is powered by a motor Didel MK04S-10 4 x 8 mm Pager 10 ohms . The remote control is amateur built according to a scheme by K. Tanaka. The plan is from Andy Mitas.

The bottom of the model is generally not touched, to allow an easier access to the electronics (the winding wires are 0.03 mm !). We notice at the top the Pager engine and its reducer. Further down to the empennage is the Li-Po battery on which the infrared receiver is glued.

This model of the Piper Vagabond  (in) has its plan published in a review of Bill Hannan. The fuselage is lined with Japan Esaki paper . The wings are covered with mylar and colored yellow with an airbrush. The registrations are made with decals in mylar support .

Pietenpol Air Camper  (in) , according to a plan by Bob Peck. It is on the pistachio scale, that is to say that its wingspan is 8 inches ( 20 cm ). Its weight is 4 g .

This micro-plane is a model of inspiration “golden age” aviation. The Pietenpol Air Camper  (in) was one of the first aircraft homebuilt aircraft (1928). The fuselage is lined with capacitor paper and the wings are covered with mylar passed to the painting “old canvas” using an airbrush . We see the receiver and the battery glued under the fuselage.

 This plane, HM210, is a variant of Henri Mignet’s ” Pou-du-ciel ” . The construction presents some difficulties, especially for the fuselage. For the flight, it is necessary to take good care of the settings, especially the piqueur and the antiouple of the propeller . The fuselage is lined with white Japan paper and wings with mylar painted white.
Model pistachio scale of a Nesmith Cougar  (in) , a span of 8 inches and a weight of 4.5 g .

It is a model really easy to achieve and a safe and enjoyable flight. For once, the engine is almost completely concealed by the hood. The white propeller is of personal construction, from a plastic cup.

Notes and references

  1. ↑ ” RC Helicopters ”  [ archive ] , Micro-aviation (accessed January 25, 2017 )
  2. ↑ ” Micro-RC planes ”  [ archive ] , Micro-aviation (accessed January 25, 2017 )
  3. ↑ ” Mini RC motorgliders ”  [ archive ] , Micro-aviation (accessed January 25, 2017 )

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