Report KD 750 can be copied for free from my website:
www.kdwindturbines.nl at the menu KD-reports. The title of this report is: "Calculations executed for the rotor of the VIRYA-5R windmill (lambda design = 6.5, Gö 711 airfoil) with a 2-bladed rotor made out of Roofmate, glass fibre and epoxy".
This rotor is an alternative if good quality wood for the 2-bladed VIRYA-5 or the 3-bladed VIRYA-5B3 isn't available. Already in 1977 I have built a similar but smaller rotor which was destroyed in a big storm because the windmill had no safety system and because the rotor wasn't strong enough. This new VIRYA-5R rotor is considerably stronger because it has a lower design tip speed ratio of 6.5 instead of 8 and a relatively wider and much thicker airfoil. A photo of the original rotor is given in appendix 1 of KD 750. A picture of the new rotor is given in appendix 2 of KD 750.
