Anyone got any good tips on how to accurately balance a large jet? I'm checking the CofG on my Eurosport and it's not easy on my own - 8ft long and 25lbs doesn't allow the good old fingertips method!!! How did/do you guys do it??

I put a stick on the bottom that covers the main wheel well. With the gear retracted I use a 1/2" dowel between the stick and the table top. Roll it fore and aft to get the balance.
Darryl Usher

the same thing, neat idea !!!!!


Terry
San Antonio

Use the hanging method with a plumb bob....

I've used the plumb bob method on my two jets and both flew with no worries (Yellow F-4 and Byron F-15 twin)

Check out Joe Luptons site for full details and Stuka pic (above) gives you great info. http://members.cox.net/jluptonjets/

If gear retracts aft I balance with gear up. Cycling gear while hanging gives you idea of how much shift in CG also (usually 1/8-1/4 inch) so you are prepared. Once that is done I add fuel to see if CG shifts to far aft.
- (For F-4, to help rotation with scale gear location on takeoff, Bob Fiorenze, recommended changing fuel tank location aft and fan forward. He was right!) CG when fully fueled and gear up is 1/8 aft of panel line at (8/14 CG) and then burns down during flight for landings.

I'll have to try Darryl's method also as it seams very simple.

I have used the method used by full size aircraft.
You need three kitchen scales and you get the weight of each wheel, measure the distance between the wheels and calculate the CG from these figures. It is very accurate and you can calculate the effect of moving any heavy part to another position easilly.
I can post the formula if required. I made a simple excel spreadsheet.

Regards