I am building the KR-1B. If you plan on building the KR-2 with the -1B wings, DON'T DO IT! The plans state very clearly to NOT use the -1B wings on the -2 as the -2 (or -2S, for that matter) will not take the stresses. That is from RR. If you're building the -1 and want to build the -1B wings, the difference in the outer wing panels (besides being considerably longer :WS 17 feet vs 27 feet) is the spars are thicker and the WAF's attach with the forward spar WAF on the inside and the rear spar WAF on the outside where as they all attach inside the center spar WAF's. You can get away with a LITTLE BIT of stretching of the spars and with extended wing tips, but don't, DO NOT put the -1B wings on the -2 or -2S. Now, if you're going to build a solid spar, you're in a whole different ball park. I would still test a solid spar to ensure it's integrity before flying it as a motorglider But again, RR is emphatic about using the -1B wings on the -2 or -2S.
Gene Leone, Worland, Wyoming "Michael Moore is living proof to never trust anyone who is bigger around than tall!" -------Original Message------- From: Bubba List-Post: krnet@list.krnet.org Date: 02/09/05 08:26:36 To: gle...@rtconnect.net Subject: Re: KR> Spar questions B. Ferguson wrote: > Hello, > > With this discussion on spar strength I was curious to know if any of > the techniques discussed, along with the extra thickness of the 5048 > airfoil, would add enough strength to the center section to allow for > fitting of the 1-B wings? Adding a large amount to the span would no > doubtedly lower the g rating, but would it not be feasable to build a > 2-B using a laminated center section to beef up the structure for the > needed support? The outer parts of the wings have suprisingly little load on them. At the tips it's nearly zero. So The long wings built with long 2S spars should be fine. That's just my opinion though, I haven't seen the changes to the 1B wings. > Steve and I have a lot in common, we're both in Houston headed for > Reno. He wants to race and I'd like to catch some of that Minden wave. I'm planning on flying out there this year, KR or not (most likely some misc. spam can), if you feel like going the long way. One of these days I'm going out to Waller, too. It's unbelievably cheap to rent a club sailplane. Like $9/hr plus tows and dues. > Been lurking here for most of 2003 and have found the discussion > interesting, so I finally decided to throw out my first newbie/dumb > questions. As for me I'm not an engineer, but one sure fire way to see > if the spar would take the weight would be to build one and test to > destruction. If anyone has a slightly less expensive solution I'd love > to hear and yes, I need to do some homework with regards to wood > strength, any suggested reading besides the archives? I'm sure anyone > that might want to avoid the hassle of medical exams would be too. > (trust me doc, my prostate is A-OK) I would destruction test a pair of spars if I had the capability. I don't have any way of putting 4500 pounds of pressure on anything, much less getting the load distributed right. And the medical sucks. I got my first one the day before my 16th birthday and he STILL had to check that. Insane IMHO. > KR design decision made, still gravity bound on Suzuki. Buell and Kawasaki for me ;) -- Steve N205FT mystic...@swbell.net He who seeks will find, and he who knocks will be let in. _______________________________________ 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
