tag:blogger.com,1999:blog-4416976019310059172.post3157979135963155721..comments2024-03-03T05:25:14.284-08:00Comments on The Long EZ Build: Top spar capAryhttp://www.blogger.com/profile/14914208726502866360noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-4416976019310059172.post-32780993858792871972015-03-10T10:53:46.662-07:002015-03-10T10:53:46.662-07:00Thank you, Hank for the positive comments.
To ans...Thank you, Hank for the positive comments.<br /><br />To answer your question about the waves – the short answer is because having waves in your spar caps drastically decreases the spar’s loading capability.<br /><br />The best way I can try to explain it is picture straightening out a paper clip so that it is perfectly straight (straight like a toothpick). Now try pulling on the ends – pretty darn strong! Now bend the paperclip into a ‘U’ shape. Pull on the ends. Is it strong? Nope! The ‘U’ shape will bend and deform fairly easy.<br /><br />Having waves on a spar cap means the UNI fibers are acting like mini ‘U’ shapes and do not have the same tensile strength that perfectly straight UNI threads have.<br /><br />The question now becomes how straight is considered perfectly straight. Well, they really should be straight - enough to the point where you can’t pin point a wave. I haven’t done the calculations but I would assume that having a single isolated wave (the size of a nickel or a quarter) isn’t a major issue – since the UNI threads that are straight right next to the wave will take the load. That said, if you have a very wavey spar cap – it might be cause for rejection.<br /><br />I hope this helps.<br /><br />-AryAryhttps://www.blogger.com/profile/14914208726502866360noreply@blogger.comtag:blogger.com,1999:blog-4416976019310059172.post-55010083815392506542015-03-09T21:46:54.588-07:002015-03-09T21:46:54.588-07:00First, beautiful work! Second, thanks for the edu...First, beautiful work! Second, thanks for the education. Third, I hope you can explain to me why the plans say to look for waves in the top of the upper spar cap. This is in the last section of the plans, listed as "common errors" and it explains how to correct them. Mine had waves. I don't know why.Hank Clarknoreply@blogger.com