HOTRODJOHN

Ive got a 30% Carden Extra with JR4721s throughout, 1 servo per aileron, today during a level flight at near full throttle one of the ailerons stripped resulting in severe flutter. I slowed down and landed easily, does this size plane (89 inch wing) need metal gear servos on the ailerons to prevent this from occurring again???

Tired Old Man

My Feedback: (1)

I've got a 30% Extra 230 and I would not consider flying it with plastic geared servos. You may want to consider using 2 4721s' per aileron if you want to use plastic gears.

In all candor, I've stopped using standard geared servos an any high performance aircraft to eliminate the problem you have just experienced. The last nylon geared servo I used was the standard JR servo in a Pizazz. Guess what, fluttered so bad I almost lost the plane.

Pat Roy

Giant Scale

High speed, large control surfaces and or sloppy linkages can all contribute to flutter. The 8411 in my opinion would probably be a better servo to use. Seal your hinge gaps and use high quality linkages such as rocket city and hangar 9. This should solve you flutter problems.

Carroll-RCU

My Feedback: (43)

John, Sorry to here this happened. To all that replied, I built this plane and sold it to John and it has the standard size control surfaces. All gaps were sealed with Monokot top & bottom. Dennis at Carden designed this plane for the single servo per aileron in the standard build. I am a little concerned that the 4721 stripped in level flight. John, Did you notice any slop in the aileron control linkage? Is it possible that you bumbed the aileron while unloading the wing from your vehicle? This is a very reliable and strong servo that is used by a lot of big bird fliers. The gears don't strip that easily. Flutter could have also occured first which could have also stripped the gear. Also, did you move the aileron clevis any closer to the control surface? This can cause flutter also.
I'm real curious as to why this happened so, please excuse all the questions.
Thanks,
Carroll

Jemo

My Feedback: (5)

I am using Hitec 5945 servos on my Carden Extra 30%, with TOC mods.
They seem to perform very well, even with a single servo on the rudder.

3D_CAP232

Hi,
I agree with Carrol..do you know that the aileron servo striped then fluttered or was the flutter the cause of it to strip? Hard to prove but something to think about.
Mass balancing can help too which is often overlooked

The other thing is with (making a big assumption) 3D geometry on your surfaces the holding power of the surface will be less than 'normal' throws therefore some 'mechanical sympathy' is probably required...i've seen too many large models damaged by simply going too fast (bits flying off or flutter etc)...please remember fullsize have max airspeeds, so why not models!!
Just my £0.02 worth!!
Happy Flying