Windmill rotors were designed at that time using reports which are now difficult to obtain. After CWD ceased to function in July 1990, I started my own private engineering office Kragten Design (KD), specialising in the development of small electricity generating windmills and in providing a wind energy consultancy service. I wrote many reports on generator tests and also a report on matching windmill rotor and generator. I decided to write and publish this report KD 35, because I believe there is a need for such a report in which the basic knowledge of rotor design and matching is brought together, so that only one report is necessary to design a windmill rotor. The most important reports which I used are:

1. Horizontal axis fast running wind turbines for developing countries, CWD publication 76-1 (ref. 9.1).
2. Rotor Design for horizontal axis windmills, CWD publication 77-1 (ref. 9.2).
3. Catalogue of Aerodynamic Characteristics of Aerofoils in the Reynolds number range 104-106, TUE report R 443 D, (ref. 9.3).
4. The Gö 622, Gö 623, Gö 624 and Gö 625 airfoils with thickness/chord ratios of respectively 8 %, 12 %, 16 % and 20 % for use in windmill rotor blades, report KD463 (ref. 9.4).
5. Rotor Design part 2, TUE report R 1078 D, (ref. 9.5).
6. Rotors, TUE report (has no R number), (ref. 9.6).