Viper vibration problems
 

I have a new viper where the left aileron vibrates like crazy. I have tried both my Novarossi 50 and MVVS 40 with the factory back plate with no change. I have checked the hinges and all are tight and the torque rod has little play. If anyone has any ideas please help.

James

RE: Viper vibration problems
 

You might want to check how stiff the aileron is. If the wood's a bit on the soft side, then it would lack torsional stiffness, and this would allow one end to vibrate while the other's held by the linkage. If you can twist the tip up and down a lot, and the root end doesn't move, you have a soft piece of stock for the aileron. The only cure is to replace the aileron.

RE: Viper vibration problems
 

I'd try a different aileron servo also.

Dave

RE: Viper vibration problems
 

Ways to fix a buzzing racing aileron assuming servo and linkage are AOK:

1) - Tape hinge bottom with 3M clear 200 MPH tape. This will often cure it.
2) - Tape the outside corner with clear 3M 200 MPH tape.
3) - Strip covering off top and bottom... soak with thin CA in a zig/zag pattern.
4) - Strip covering off top and bottom... use thin CA and 3/4 oz FG to strengthen aileron.


Start at 1 and work your way down... you probably won't get by 2 without curing the flutter. Good luck

RE: Viper vibration problems
 

Is it vibrating on the ground or fluttering while flying. If while flying how do you know its the left one? We can't even tell which surface is fluttering in the air. In any case try the tape as sugessted above. If its vibrating on the ground I would look hard at the hardness of the wood and consider changing it.


Barry

RE: Viper vibration problems
 

Thanks everyone for the suggestions.

bl10 - It is fluttering on the ground. The flutter is bad enough I did not want to attempt a flight.

Bax & daven - I check the stiffness of the aileron wood and you were right it is very soft compared to the right aileron. I took off the covering and the aileron so soft that I could deflect the end with very little pressure. I am replacing it now.

DMyer - Thanks for the tape ideas. I would have never considered this. I will keep it in my bag of tricks.

Just starting out in Q-500, after some pratice to get the feel of the planes I will start making the races, hope I get a chance to meet some of you. Also, I realize the Novarossi is not legal, just a fast engine I had laying around.

Thanks and Regards
James A. McGuiness

RE: Viper vibration problems
 

James,

Just a semantic note -- if you're seeing it vibrate on the ground, I wouldn't call it "flutter" as understood by aeronautical types. What you're seeing is slop, flex, or some kind of harmonic vibration. It will surely lead to true aerodynamic flutter in the air, but it isn't really "flutter" yet.

You did the right thing by replacing the aileron with a piece of stiffer wood. Other than that, sealing the hinge gap with tape is the next best thing you can do to prevent flutter in the air, whether or not you see it wiggling on the ground. This will also increase the effectiveness of the control surface. On one of my sport planes I just about doubled the roll rate by sealing the aileron hinge gap. For racing this means you can cut down the throw (control surface travel), which reduces drag, which in turn results in more speed.

Speed is good. ;)

DHG