C of G

[Jenko]

Hi All, Have a Comp r 2.6 Yak Da100. If the Cof G is to far rearward would this make the ailerons more sensitive, like the airplane wings don't remain stable in level flight when flying Imac.
Any opinions would be appreciated.

[Reza]

It makes your elevator really sensitive. Plane would react to small movement of elevator. Downline vertical won't be straight. For IMAC flying you need to have either perfectly balance or slightly nose heavy. The way you are saying your plane is very tail heavy. Planes that are very taill heavy are typically harder to control and precision flying harder to achieve. Knife edges are more off and having scale landings is harder. Plane comes in nose up and tail down.
and more and more. get the CG right on or slightly nose heavy for IMAC.

[Kiwi]

Jenko.

Try to explain a little more what you mean by unstable. Do you mean it wing rocks in straight and level flight at a medium speed or are you referring to it in a harrier type situation.

Does it want to roll just one way. The question is very vague so likely wont get too much respoonse unless you can get us some clearer information.

Let us know and your sure to get help.

Kiwi

[notorious_benny]

Hey Jenko! Where do you have her balanced at the moment??
I have mine right on the wingtube when she is all put together minus the wings, this is definitely nose heavy but makes it fly IMAC real smooth.

Its unusual you are getting instability on the roll axis, CG should not effect the roll axis. Is it rocking in the calm weather as well as the rough stuff mate?

[Jenko]

Kiwi, Only in imac and at medium to full power you just need to constantly correct for wing rock i.e. rolling but it only slight, I have a fair amount of expo and only enough travel for a nice roll rate when doing point rolls.

[Jenko]

	Quote: Originally Posted by notorious_benny
	Hey Jenko! Where do you have her balanced at the moment?? I have mine right on the wingtube when she is all put together minus the wings, this is definitely nose heavy but makes it fly IMAC real smooth. Its unusual you are getting instability on the roll axis, CG should not effect the roll axis. Is it rocking in the calm weather as well as the rough stuff mate?

Benny, Supporting the plane by the wing tube the tail hangs at about 30 -40 degress down. I guess from you are saying this could well be tail heavy. It has always had this symptom so maybe I should move some batteries forward.

[notorious_benny]

Give it a go Jenko, remember I have it set for my preference though. I am at work at the moment, if you want to wait I will check it tomorrow morning and tell you exactly how it balances with the wings off.

From memory I think it is actually nosing forward a little when picked up by the wingtude.

[rcdart]

Dear Geoff, hate to say it, but mine, like Bens, is level when all together, but wings off and suspended by the tube. I am actaully going to move it a bit aft this weekend, to see if the spin entry is better, so I will let you know if it effects anything else.

[notorious_benny]

Hey mick, wont pushing the cg aft make it less willing to stall cleanly?? I think it would be more likely to want to mush around.

Since I installed the pipes I have re-balanced a little bit further forward of where I was originally.
I have noticed since doing this that I need far less elevator to initiate the stall, actually I keep it on the same rate as I do for the rest of the sequence now.

[rcdart]

Horses for courses Benny, we'll see. Not saying I'm right, but easy exercise to try.

[Stu_D]

Benny mine sounds to be about the same as yours . When i pick up
the plane by the wing tube she is a bit nose down . I had to put a
spare 5 cell pack behind the fire wall to to her just right .

That being said after only a dozen flights what would I know .

Benny , you had the straightest yak @ bendigo but the bloke
holding the sticks may of had something to do with that . Then
again Micks was pretty good .

Stu D

[Jenko]

Thanks for all the imput guy's, I reckon I will shift the CofG forward and see what happens. But it is probably the connection between brain and thumbs failing.