center of gravity..How Close??
 

Hello. I am building a hanger 9 showtime 4d and my CG is approx. 1 inch too far to the rear. As per the instruction manual. Is this close enough or should I add lead weight to the front? I would like to keep it as light as posible. Moving my battery pack is not an option as they have a recess for it already. Any advice on CG would [8D]be greatly appreciated. Thank you in advance for the help.

RE: center of gravity..How Close??
 

G'day Mate,
1" is a long way out, 1/4" changes can be detected when flying, make sure you are on the recomended CG point or even a tad forward, fly it & then adjust as required.

RE: center of gravity..How Close??
 

Add the weight!!!

Nose heavy planes may fly poorly. Tail heavy planes may fly ONCE!

Dr.1

RE: center of gravity..How Close??
 

I don't care if there's a gold placard showing where the battery goes, move it forward. Strap it to the side of the Engine Box and drill a hole through the firewall for the wire if you need to.

Then, if it still needs it, add lead.

As was said before, you can get away with being a little nose-heavy, but you do NOT want to fly a plane that is Tail-Heavy.

RE: center of gravity..How Close??
 

A very nose heavy plane flies poorly..... A very tail heavy plane flies only once!! :D

Ken

RE: center of gravity..How Close??
 

Minn beat me to it... Find a place to move that battery pack forward. Make a spot for it if you can. Usually a couple of small holes drilled to accept zip ties will work very well.

Then add weight if that does not work.. I would not add weight unless you have no other choice as the plane will not fly as well with added weight.

However, in case you havent already heard it before;) Nose heavy planes fly like crap, tail heavy planes only fly once.

RE: center of gravity..How Close??
 

If you do have to add weight, consider a heavy prop hub that fits under the spinner. The farther forward you add weight, the less you have to add. And since nobody has mentioned it a nose heavy plane flys poorly, but a tail heavy plane flys once. :D

RE: center of gravity..How Close??
 

Awesome advice gentlemen, thank you. Looks like I'm drilling some holes to move the battery pack...

RE: center of gravity..How Close??
 

And since nobody has mentioned it a nose heavy plane flys poorly, but a tail heavy plane flys once.

Mike East
RCKen
Dr1Driver

Perhaps you missed their posts? :D

However, it DOES bear repeating.

Dr.1

RE: center of gravity..How Close??
 

Using a flat pack we were able to position the batteries under the fuel tank and added a small piece of balsa to keep them from sliding aft (just in case).

We ended up having the cg 1/8" toward the tail.

RE: center of gravity..How Close??
 

I had a nose heavy airplane once, it really flew poorly. I moved the CG aft so it was tail heavy and it only flew once. :D
regards,
doubledee