> Dene: Hello > > I think you will find that the CG remains very close to where it was > originally. What will move back is your center of lift. The CG may > still be within limits but you would need to check. Moving the Center of > lift rearward would increase the work load of your horizontal stabilizer > as it will need to provide more down pressure to balance your load > /lift. I'm not saying it couldn't or shouldn't be done just realize what > he results will be and adjust accordingly. > Russ Breckenridge, MN [email protected] > > > > _______________________________________ > to UNSUBSCRIBE from KRnet, send a message to [email protected] > please see other KRnet info at http://www.krnet.org/instructions.html > -------------------------------------------------------------------------- -------------------------------------------------- Hi Russ The way I see it is this: In stead of using lead weights or a longer engine mount to get the planes Cof G in the correct position, I am proposing moving the wing back to bring the C of G range to meet the plane's "balance point". Remember the C of G of an aircraft is determined by the wing or more accurately the airfoil used and not the fuselage. The aim is to get the "balance point" of the fuselage and wing combination to match up with the calculated Cof G range of the airfoil. You are correct in saying that the c of g will hardly move but it will now be 28mm further forward in the allowable range. If I do move the airfoil relative to the spars it will only need to be moved by 28mm which will still keep the centre of lift on the spar although it will be nearer the leading edge than the aft edge. This mod is not to correct a cg problem but to acccomodate a rear spar that was built 4 or 5mm too tall. The spars are by default much stronger than required anyway so I might just shave off a couple of mm from the spar and stop stressing. Dene Collett South Africa mailto: [email protected] P.S. Checkout www.whisperaircraft.com
----- Original Message ----- From: "francis fenlason" <[email protected]> To: "'KRnet'" <[email protected]> Sent: Monday, January 19, 2004 4:05 PM Subject: RE: KR>rear spar HELP
