Empty, I have the CG just behind aft limit, full, and the CG lies just infront of the forwaard limit, but the manual does not specify, and with the tank (as per instructions) well forward of the CG, it'll make a difference.


Aircraft is an H9 Funtana 3D.

Your wise words are appreciated.

always set the center of gravity with the tank empty as this will make it more stable on landing

Be CAREFUL... Funtana S fliers have found aft can be "interesting"!
It's easier to add ballast and take it out once you feel out the airplane, than rebuild!

If the tank is in front of the CG... check with tank empty. (90% of RC models... including yours.)

If the tank is aft of CG check with tank full. (some pusher designs.

The Dornier "push-me-pull-u" (what was that fighter?... prop on nose and prop on tail.) forward tank empty, rear tank full.

If tank is on the CG... it really doesn't mater.

Balance it for worst case aft CG. and the CG will never get worse after take-off than where it was when you balanced it.

Well... it's better to have your fuel tank near the CG so it doesn't shift at all. Your stability/handling characteristics change when your fuel tank isn't located near the CG.

Thanks folks.

I've set it just in front of the aft limit with dry tanks. As a made up kit; it's very impressive, but you're pretty much stuck with the layout. Any modification at this stage will inevitably add weight. I'd like to move the ELE and RUD servos further up the fuselage rather than add lead to the nose, but job done, lets see how she flies.