Bill: The Formula I used was for a solid beam not a KR2 Spar because the Spar is a "Composite build of (2) solid beams(plywood skins) and the spar caps separated by a distance and the "Crippling" can be ignored.
Primarily the added strength comes from the added depth section which is taken to the 3rd power so its strength increase is tied to the difference in the cubes of the depth so you must adjust for the void space between the spar caps. There are some things here I am not real clear about mostly because I have no rigorous training on the applications. don ifly...@aol.com wrote: > Thanks for the info on spar wood guys. For those interested, I do need a > center spar length that is 2 feet longer than normal. The 18% chord AS > airfoil will improve the strength and load bearing necessary for my project. > The > Taller spar is about 20% stronger than the stock spar which will be necessary > because the airplane I am designing is about 250 lbs heavier than my 2S. > Instead of foam/glass on the center stub wings I am probably going to be > using > wood ribs and ply on the surfaces. It will be comperable in weight but > stronger. The ribs may also be made out of Nomex - a carbon honeycomb > material > that is extremely strong and light. Many ideas but they are still on the > drawing board. This will be custom built and a true experiment. More info > to be > coming...... > > > Bill and 41768 > > _______________________________________ > 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
