Sal -the model as you describe it is tailheavy for precision flying.
For best results - determine CG (25% back from LE , at the average chord.
the average chord is at 1/2 of a wing panel measured from the tip
Example: span 73" =18.25 " from each tip.
so IF the chord at that point is oh--15" , then 25% of 15 would be , 3.75.
If after balancing it there, it still pitches heavily from a hands off level flight cruise speedtrim---- then mixin up with rudder till it is managable-you won't ever get it perfect as that just isn't part of the setup.

Hi dick, I'm sorry but maybe i didn't make my self clear. I was talking about It's pitching tendency's in Knife edge flight. I was under the assumption that an aerobatic plane like the Edge would have very little coupling in knife edge flight, and mine pulls really hard to the belly and rolls out to the left when top left rudder is applied. I can easily dial it out within the radio but i believe this would just be masking a bigger problem.

I flew it last with the CG at 4 1/2 from LE which was 35% of the MAC using your recommended calculation.

I built 0 degrees of incidence into the stab compared with the wing,and all control surfaces are straight and true. I love knife edge flight and love to do all the low knife edge maneuvers like loops, snaps and circles, but i must have very stable and reliable control without holding other controls excessively to do so.

I basically was asking for your info Mr. Hanson because you do have the same plane and engine combo as I, and your experience with models is well noted here on RCU.

- I do understand - and the 25% recommendation is valid.

Thanks again.

sal98, Dick is correct, the C.G. location will change the pitch tendency in knife edge. Moving the C.G. back will cause the elevator to be trimmed slightly down for straight and level flight. When you roll to Knife this down trim will cause the plane to pitch to the gear.

yes -even if you do not SEE any down trim - effectively - the download is less on the tailplane and when gravity is removed from the wing - then the power will pull the attitude to a "nose down " attitude.

OK, I'm starting to get this aerodynamic thing. So when you set up a plane for 3d or freestyle type flying by moving your CG aft, you also must take this pitching tendency's into account and add your appropriate mix in your radio?
I Really want this plane to be set up for precision type flying, so i guess i will keep moving the CG forward until i find that sweet spot.
Thanks guys for the help.

You will find that "sweet" spot between 25%-30% MAC. Also the new planes have very large and powerfull control surfaces, it's just not necessary or advantages to use 35% and beyond for C.G. I think you will find it does everything better around 27%,and Dick is right you should start at 25.

I'm glad that Dick explained about the CG being measured from the average cord. I never really understood this when i read about it in certain articles. This in effect would put the recommended CG location between 35% and 41%
With most guys stating they like the CG at 4 inches, this would be setting it up at 31%.

The C.G. is always measured at MAC, 27% MAC may be 4 inches at the root but it's still 27%. Don't confuse C.G.% with balance point at the wing root, they are not the same thing. Think about it this way, 25% MAC of an F-86 Saber would be behind the trailing edge of the wing at the root because of the wing sweep, but it's still 25%, I know it's a little confusing be trust Dick, MOST of the time he knows what he's talking about {you know I'm kidding..........right Dick?}

I just reread dave patricks aerobatics manual were he explains about finding the MAC on wings other than a rectangular shape wing.
At the time i did not understand what he was saying regarding trapazoideal shape wings with tapered wing tips. But Dicks comment's shed some light for me .
Only on a retangular shape wing were the chord at the wing root is the same as the chord at the tip, will you find that the Mac is the same distance from the Leading edge across the whole length of the wing. But on other shaped wings like on Caps, Giles and Jets the mac is calculated at the middle of the wing panel.

Dave Patrick also stated that once you find the desired mac for one wing panel, you can do the same for the other wing panel and then draw a line between the two. The CG would then be anywhere on that line.

Right on, you got it!

On the 5th fight the wing broke at fusealage and where the aileron starts. Taking the covering of it is not built to good lots of places no glue none on the caps on the ribs just at ends. I was flying 140 Y/S on it it flew good till it srarted coming apart. I was able to land with out a crash but it was a job it was way out of trim when the wing broke. I am going to get hold of hanger 9 monday see if they will replace it. I have been flying for 45 yrs. and this was the hardest one i ever landed, when it got slow it was wild as a wild hog. Be careful the wing is built very weak.

James