White Pointer AXFX

Author	Message
Trev Guru Joined: 15/07/2006 Location: Australia Posts: 676	Posted: 10:25pm 09 Jul 2011       I always have the dream of making something easier. I bought some alloy aerofoil extrusion from Phil a long time ago. Thought it would be easier for blades (and cheaper too than my own fibreglass blades). They were 2200mm long, and with the hub, made a diameter of 4.6m. The idea is to catch the low wind, which is what I usually have here. The extrusions are easy enough to assemble. I fitted them up with mild steel 25mm about 300mm long into the hub I machine. I already had the hub made. It didn't take very long to fit the blades and hub together. Being so huge I could not check for balance. I was relying on the extrusions to be of equal length and distance, thus equal weight in each blade. Swapped the blades over on the White Pointer AXFX. They seemed a bit flexxy and thought they would not last. But oh well, it is a test so up we went. The blades started spinning before the tower was right up. Balance seemed ok. They seemed to spin at reasonably high speed, but did not get any real time to watch them. As the tower neared the top, the blades started hitting the welded brackets where the cables tie on. A big mistake! I should have had more bolts through the blades and steel bar. 1 bolt allowed the 2 outer skins to seperate allowing the blades tips to flex. The tower was up and straight back down. Trev @ drivebynature.com