At 01:28 PM 10/15/2005, you wrote: >just to get a dicussion going. I have a hypothetical question to the >net and I'm sure it's been either done or thought about. > If one decided to mate a KR wing set to a truss type steel tube fuselage > how would one go about doing it? >. snip >How would one bolt the wing to fuselage attach fittings to the spar, >would you use the >same bolt pattern as on the wing attach fittings or use 1/4 inch >bolts on center of the >fitting 3 on one side of the 5/16 inch mounting bolt and 3 on the other side. >I hope my question is clear enough
It would certainly not be difficult to design an attachment of this type but an on-line forum is not the correct place. You need some engineering analysis, not just a "that looks about right" feeling. Based on my analysis of the KR wing, if you took a KR outer wing panel and moved it to the root of a fuselage, 3 1/4 inch bolts through the wooden spar cap are not nearly enough unless there are large diameter load bearing bushings in the spar cap. The minimum number of bolts that can be used to bolt a spar cap are 4, and the diameter of the bolt or load bearing bushing in that case is 1/3 the thickness of the spar cap. For example, if the spar cap is 3 inches thick, including any taper, you can design a fitting that will need only 4 bolts through the wood, but they must be 1 inch in diameter. Since you would not want to use a bolt that large, they would be about 3/8 and they would pass through a bushing made out of aluminum that is 1 inch OD that is in the spar cap. There are other designs that use a wooden cantilever spar bolted to a tubing fuselage, so yes it is do-able. Don Reid - donreid "at" peoplepc.com Bumpass, Va Visit my web sites at: AeroFoil, a 2-D Airfoil Design And Analysis Computer Program: http://aerofoilengineering.com KR2XL construction: http://aerofoilengineering.com/KR/KR2XL.htm Aviation Surplus: http://aerofoilengineering.com/PartsListing/Airparts.htm EAA Chapter 231: http://eaa231.org Ultralights: http://usua250.org VA EAA Regional Fly-in: http://vaeaa.org
