This site gives a good way to calculate your c.g. range based on taper and sweep...figure 15 to 35 % mac
http://www.nasascale.org/howtos/mac-calculator.htm https://sites.google.com/site/mykr2stretch/ https://sites.google.com/site/mykr2stretch/parts-for-sale On Mar 30, 2016 8:14 PM, "Pete Klapp via KRnet" <krnet at list.krnet.org> wrote: > KRNetters > I am in the process of determining the cg on my project. In comparing cg > location, RR plans show the 8" cg range with the fwd edge of the range > starting 8" aft of the leading edge of the wing. Based on the profile of > the 48" rib, the leading edge of the cg range is 2" fwd of the front face > of the main spar. I have Diehl RAF - 48 skins along with inboard skins that > Jeannette Rand also produced. With those, the leading edge of the wing is > 11.5" fwd of the front spar face, an 1.5" fwd of RR plans. Should I move > the cg envelope fwd by that 1.5" or use the cg range set by RR. > Next question: Preliminary calculations show my empty cg is approx. an 1" > fwd of the RR cg location. Knowing that any weight added, passengers, fuel, > baggage, etc will fall push the flying cg aft, should I fabricate my engine > mount using this calculated engine position? > I have done calculations with pilot plus 1/2 fuel and it falls at 2" into > the RR cg range, and pilot & passenger plus 3/4 fuel and cg falls within 6" > preferred cg range, the later coming in right at the aft edge of the > preferred range. I'm thinking that I would like set the engine such that > with me and 1/2 fuel that the cg falls right at the fwd cg limit. > > Next question: The horizontal engine centerline with the temporary engine > mount is 2.5" below the top of the upper longerons. I'd like to drop the > centerline a little more, 1/2 to 3/4", for better clearance for engine > cowling and cooling plenum. Anyone see a problem with that. > All advise cheerfully accepted, > Thanks in advance for any and all assistance. > Pete Klapp > > _______________________________________________ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options >
