Thanks for the advice -----Original Message----- From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf Of Mark Langford Sent: Friday, February 04, 2011 6:28 PM To: pharri...@penumbradesign.net; KRnet Subject: Re: KR> Lay-up
Phillip Harrison wrote: I' planning on a veil did you use one? No, if you mean did I use a Kevlar veil. That one thread was more Kevlar than I needed or wanted on the plane. What you may be missing is that the real structure of a KR wing is the wood spar underneath the skin. The skin's not going to fail unless you strike it with something, and if they are carbon fiber you'll break out a chunk and either continue your crash or keep on going (if it was a Canadian goose). The only reason I used carbon fiber on my wings was because I could make the wing a little lighter, yet much stronger (to minimize hangar rash and survive the inevitable runway light collision), and I could afford the extra cost (back when CF was "cheap"). You asked for advice, and I guess that's mine. You are welcome to use Kevlar and extol it's virtues after you're done. This reminds me of a conversation I had with the chief engineer this afternoon. He wanted some advice on cutting cost out of a 10" diameter carbon fiber tube for a piece of space hardware that we were asked to quote to build. Unidirectional prepreg CF tape .0002" thick was specified by the customer, which cost $700/lb, with a 25 pound minimum order. Wall thickness was called out as .040" to .090", so it was going to take something like 200 layers of this stuff wound around the tube to get to minimum thickness. It took me about 2 seconds to bust out laughing...why would anybody specify the most expensive and laborious way to build this piece if the weight of the tube had a tolerance of more than double the minimum weight and thickness? Mark Langford ML at N56ML.com website at http://www.N56ML.com -------------------------------------------------------- _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
