Larry's AC50 Circus in America's Cup Anarchy Posted May 14, 2018 1 hour ago, barfy said: And i know what an IGES file is, in this case it imposes a 3d point/edge defined box rule rather than a crude box. This does not imply exact duplicates as the slots, flaps, and control arms just need to fit in the box. IGES implies nothing because it is a file format that is neutral and can be read by a wide range of cad systems. I am not sure where you get the idea that the files simply defined a box rule. Each component of the wing was exactly defined and those components were a strict one design shape. To quote Seahorse Quote the AC50 wing is effectively one-design in terms of its shape, layout and geometry. https://www.seahorsemagazine.com/106-content/march-2017/460-unclipping-the-wings The shape of the components might have been fixed, by the construction and control systems weren't.