The rotor of the VIRYA-1 has two aluminium blades made out of one strip.The rotor of the VIRYA-1.04 has three separate aluminium blades. The rotor of theVIRYA-1.36 has two separate stainless steel blades. All blades have a constant chord of123.3 mm and 7.14 % camber which simplifies manufacture. The rotor calculations of the VIRYA-1, the VIRYA-1.04 and the VIRYA-1.36 are respectively given in the free reports KD 574, KD 518 and KD 571. The VIRYA-1.04 uses a Nexus bicycle hub dynamo as generator. The main disadvantage of this generator is that the maximum power is rather low. The VIRYA-1 and the VIRYA-1.36 have an axial flux generator which must be manufactured completely. The VIRYA-1 generator makes use of the front wheel hub of a mountainbike. It is expected that a battery charge controller with dump load isn’t required if the battery has enough capacity. The VIRYA-1 and the VIRYA-1.04 make use of the same head and the same tower pipe.The only difference is that the vane blade thickness is 1.5 mmfor the VIRYA-1.04 and 2 mm for the VIRYA-1.The windmills are provided with a “hinged side vane safety system” to limit rotor speed and thrust at high wind speeds. The rotor axis is offset from the tower axis. The vane juts out along the rotor and the vane blade is connected to the vane arm using hinges. At low wind speeds, the vane blade hangs in almost vertical position and the rotor is perpendicular to the wind. At wind speeds higher than about 6 m/s, the rotor starts to turn gradually out of the wind. At very high wind speeds the rotor turns out of the wind by about 70° and the vane blade is in almost horizontal position. The behaviour of this system is very stable and the rotor speed is well controlled. The towers of the VIRYA-1 and the VIRYA-1.04 consist of a 1metre tubular upper section which can be connected to 3 m long wooden pole which can be connected to a supporting structure such as a wall of a house. The VIRYA-1.36 has a 2 meter tubular upper section and a 3 m wooden pole. Ten VIRYA-1.04 windmills have been built during a weekend in spring 2013 by a group of students of the University of Technology Twente. The VIRYA-1and theVIRYA-1.36havenot yet been manufactured and tested by Kragten Design but a prototype of the VIRYA-1.36 will be built by an Indian company. These three windmills are designed primarily for serial manufacture in developing countries. However, a prerequisite is that the prescribed material is available. Kragten Design cannot supply materials and parts such as bearings, generators, magnets etcetera. The required workshop skills are sawing, drilling, turning and welding.