ORIGINAL: invertmast
ORIGINAL: Falcon 64
I doubt that very much..
Once you move the CG location forward, even if it`s not in ok balance, you also improve flutter velocity indeed.
At a perfect balance, the flutter speed will be higher than the engine can take the model (depends on MAC).
A nose heavy elevator pushes the limit even further. I`ll give you an example..
What is the optimum way to discover flutter? It is to have a very loose binding to the thing that holds it in place, agree?.
Like holding it in you hand.. 45 km/h was all it took unbalanced. If you took the same elevator and tested it on the fuselage, the speed would be significantly higher. And add a strong digital servo to force it to be still, we climb even higher in speed to have flutter, but we may get there. That is the way you know it.
Thats why the flutter come so suddenly, it creates enough power to finally get the freedom it strives for, because its held in place with a snug fit, ''no slop'' in the pivot tube /bearings (not speaking linkage to servo, that comes as an addition because we are without servo here).
Then we take the same elevator which I in my case fluttered in 45 Km/h before, now WITH balance..
In my hand at 150 Km/m down the 2000 meter runway, it`s just floating at ease, no tendensies to flutter.
And we move this balanced elevator back to the airframe without any servo, we get a even higher velocity before flutter, perhaps 250-300 km/h, and that`s before it fluttered in the first place at 150 Km/h. THEN we attach a strong digital servo to it, where do you think we are heading now..?
The plane can`t fly that fast...other things will come off first, like ailerons or flutter in r/stabs or rudder, wing-flutter, you name it..
Gaula River, here I come!
If it wasnt possible, full scale aircraft manufacturers wouldnt describe in detail the exact procedure and specifications for balancing their flight controls
Do not forget full-size fighters are lightyears apart of our game..!
They go supersonic, and are SAFE behind our knowledge and can NEVER! be compared to what we do. If you build a Tomcat in the thought of full-size, you are safe no matter how, but requires the same rigidness and hydraulics.
BUT in modelleing we can`t yet do that, and that answers your reply..and that is where you have questions. Copy a full-size, and you will crasch & burn on and in the terms of the modelling in jets we have done uptil now.
I eeek every time someone compares a full-size aircraft up to their model and think they do it 7 timer smaller, and also think they are in a good path in jets and forces in it, there are dimensions! apart.. PLEASE stop thinking we can compare aerodynamics on our models with supersonic fighters.. ( ! )
Once you do, you are mislead and on your own..and you will loose.!
Our thing happens below 600 km/h, way below subsonic. It`s from there we have to admit our laws exists, not to compare your jet against the original, nothing of it, (!!)... We are dealing model airplanes, the laws there are grewing rapidly once the size/weight and speed grows whith it.
My final words in this thread are :
We have model jets with problems almost all over, made from a various group of manufacturers.
But "none of them" have a clou of what they deliver as almost all of them have fluttered down, at leat none allows a over-motorized setup..
None of them are aware of it until recently, and if they did, we would hear from them a long time ago about it.
Hard facts are often hard to comprehend, but nevertheless a fact.
A hard time for the byer(...!!...), a almos equal hard time after for the rest..friends and likes. I HOPE this thread " dies" into a understanding of the necessity to take a aim at your elevators, even though they have served you right.. Allways.
The solution IS easy. Once flutter occours, we progress/compensate with balance. But those who won`t see it continues the path.
Those who don`t, are on their own.
Allways. Period..
And I promise.. You are flutter-free on those I said..
That`s why i chimed in here at page 32..
Calories.. for a good thing. Dead horse, flutter free..
Remember that when you go down.......
Two cents or 2k kalories, hope it went in where it should..
I`m ready to defend the earodynamics in this , anytime. Just bring it on..