3wExtra

the plane reacts extremely touchy to elevator input.
that is almost no elevator input and the thing just rocks. also on turns looks like if it is dragging the tail a bit.
sorry for the stupid question but i need someone to explain this.
this is a CA 2.6 with a 3w 106 and cans, the servos are jr 8411 all around and when i balance the thing it is Nose heavy or at least on the most conservative CG advised by the manual.
thanks!
Astolfo

GalenB

My Feedback: (18)

Maybe... With the plane in trim right side up what happens when you roll the plane inverted get it level and release the elevator? Does is descend slightly, or strongly, toward the ground? Or does it climb? A properly balanced plane should descend slightly when inverted... The plane can also be neutral and neither climb or descend...

How much elevator throw do you have? Have you added any expo? Does it have the right value? Negative values on Futaba make the control less sensitive while positive numbers are used on JR. If you happened to use positive numbers on a Futaba radio you will make the control more sensitive around the center...

3wExtra

not much travel at all, and i use Multiplex and the EXpo is -27% (just like futaba). I will test the inverted flight procedure.
are there any other way to tell whiout flying it?
thanks!

GalenB

My Feedback: (18)

If you do not trust the manufacturers specified location then setting the CG at ~25% MAC is a safe starting point... Computing the MAC is easy on a non-tapered wing... Do you have a CG machine or are you simply using your finger tips? Have you followed CA instructions to the letter when setting the CG? You can also zip tie 6-8 oz of lead to the engine box/firewall as a test -- this should move the CG forward a bit... You can always add or subtract lead if needed... Then once you get it flying where you want it to be measure that CG location and you might be able to move gear around to attain that CG sans the lead... Also - is your fuel tank on the CG or forward of the CG? Stupid question -- was the fuel tank was empty when setting/measureing the CG?

Do you fly at Marymoor?

3wExtra

the fuel tank is on top of the spar (i.e.CG) I fly in baimbridge isalnd (orca).
I did both the finger and hanged the plane from its wings.
everithing looks just fine but this bird is Extremelly touch!

Tired Old Man

My Feedback: (1)

By "almost no elevator input" are you referring to stick input at the Tx, or actual movement at the elevators? Big difference depending on how you're set up.

3wExtra

I am referring to the actual movement at the elevators. it is just way too sensitive

Rcpilot

My Feedback: (78)

Thats usually a sign of tailheavy.

How does it land?

Do you have to apply down elevator to get it to come in for a landing? Do you need to apply down elevator just to keep the tail up at landing speeds?

My suggestion:
Do as Galen suggested and add 6 or 8oz of lead to the firewall. Make it removeable.
Dial in a BUNCH of EXPONENTIAL on the elevators.

Take off and climb it up REALLY high as soon as possible. Really high.
Throttle it back to idle--let it glide and see if the tail drops.

Then go ahead and fly it around at a reasonable throttle setting--say 1/3 throttle or 1/2 throttle.
Roll it inverted and see if the nose drops(nose heavy) or if the tail drops(tail heavy).

Good luck. Hope ya don't crash it. I've been in this situation before. It's not fun.

famousdave

My Feedback: (61)

What does the airplane WEIGH ?? Sounds heavy to me, not just tail heavy. You might want to check incidence as well, I have seen the tail incidence off on those planes and 2* will give you a handful, especially if the plane is tail heavy. Note also a significantly nose heavy plane will also handle like crap. Make absolutely sure its not TOO nose heavy and too heavy in generaly before you add more weight. The CA 2.6 is one of the best flying, most stable planes out there.. you should not be having this problem....

I believe a good weight for that plane is about 27-28 pounds... no more.

DP

JoeAirPort

My Feedback: (41)

Yeah that is a sign of tail heavy IMO. Do the easiest thing first, flip it inverted and with neutral elevator see what is does (like others have suggested). I would do this before anything. My last ARF flew exactly like that and it was way tail heavy. I moved the battery forward about a foot and it was beautiful.

3wExtra

I will check all this and see. I will keep looking at this post and reporting on what i find out.
thanks for the info