cymaz

Dear All

I have had a thread going for a month or two under "Big Plane Build". However I seem to have hit a snag....the aileron sevos seem to want to buzz at rest when they are in the aileron neutral position. The servos are brand new Futaba 3010 one on each aileron the links are short and straight with only a little bit of play, there is no binding on the servo horns or with the push rods and they both sit in a Slec aileron servo tray and well secured. The ailerons are vennered foam.


ANY IDEAS PLEASE[:@][:@] Here is a sketch for the aileron dimensions

yojoelay

Can I start with a basic question but - do they buzz when they aren't connected to the ailerons?

Second question - do both buzz or does just one?

Third question - are they on independent channels or a y-lead?

Fourth question - if you move the aileron with your hand can you make either on stop buzzing?

Fifith question - is it a 'buzz' or a 'BUZZ'?

Thanks,

Joel

cymaz

1.no they only buzz when connected to ailerons
2. They both buzz but if you waggle the TX stick they will come to a point and sometimes syop buzzing
3. Independent channels 1 and 6
4. Yes
5. It is still a buzz thats the problem. There is no servo twitching at all and they respond well to TX commands.

I think that is everything!!!

What is your diagnosis Doctor Servo????????????!!!!!!!!!!!!!!!!!!!!!!!

yojoelay

Well - those are the basics I guess.

I just flipped through your build thread - what kind of hinges did you use? CA hinges are stiffer than pin hinges and that can lead to buzzing.

Also - how did you install the hinges? Is it possible they are just slightly out of square with each other?

Last thing I can think of - how old are the servos?

If all of the above pass the test I'd just fly it. The servos on my Ultimate buzz and it's got many flights on it. Anyone care to disagree?


Joel

Rodney

This is because you have the weight of the ailerons trying to cause them to lower. This lowering tells the servo that the mechanical position is not correct so it tries to raise them back up so this cycle repeats rapidly (the buzzing noise). If you hold the plane so the nose is up, I'll bet the buzzing stops as the ailerons will not be displaced by gravity forces. Solution, statically balance the ailerons by adding weights forward of the hinge line.

cymaz

Cheers for that Rodney....any ideas on the design of these static balance weights???????????

cymaz

No mate, I used pinned hinges with the correct alignment. They flop around well with no bind up at all. Brand new servos,,,,nuts

FlyerInOKC

My Feedback: (6)

I have several handbooks put out by RCM and the most common appears to be a piece similar to a control horn project out in front of the aileron with an oval weighted head to act as a counter balance. I have attached a really crude drawing.

cymaz

Thanks for the input.....I am currently waiting for an answer from Futaba........and like the really helpful chaps they are,

here it is..........

Thank you for your recent e-mail. "We often receive calls from customers who will mention that they notice "servo chatter" in their ball bearinged servos. Always check your linkages and set ups for binding, servos fighting each other on the same working surface, and bad extensions to be sure that there's no problems in your physical system. Assuming there is no binding or other issues, buzzing is a common and harmless occurrence, and indicates that your servo is "checking" itself for true center. There will many times be an audible "buzz" from their servos, even when there is no noticeable movement. And this is also harmless, as when the plane is airborne, the wind over the control surfaces, and thus load on the servo itself, will correct this small amount of vibration and noise. Many times if a modeler is using a 6 Volt receiver battery, or a completely fully charged battery, they will notice buzzing, but, when the voltage drops slightly with some amount of load, the movement and noise subside. This is commonly known as 'a hot charge' and again is perfectly normal and will subside under loads and particularly in flight."

Sincerely,John G.- PS9004Product Support Lead TechnicianFutaba Programming Technician

I will put on some static balancing on the ailerons and see how it goes. Better to experiment in the workshop than take a bin bag out to the flying strip!!

cymaz

Got the balance weights done, some pictures included, do they look alright?? The servos have stopped buzzing at nuetral,thanks everyone for the help

Bax

My Feedback: (11)

Usually, balance weights are on the underside of the wing, or on a rod that goes straight forward so that they are inside the wing. On many full-size airplanes, the hinge line is displaced a bit aft of the aileron's leading edge, and the weight is contained in the leading edge. Balance weights are mostly used for flutter control, and not to prevent the buzzing of the servo.

Here's a thing to consider...if your servos buzz while trying to hold center against the static weight of a control surface when the model's not flying, aren't they doing the same thing if you have any trim input at all? That means that you are trying to hold a control surface with a small deflection away from center. The airflow in flight will try to push the control surface back to neutral, so the servo will be constantly fighting it. That's the same as having your system turned on and then holding a small deflection of the control surface with the fingers. You'll hear the servo buzz as it works to hold postion.

Really, if your control surfaces hinge freely, the control linkages are free, and the servo is in good condition with very little slop, a slight buzz while the model's on the ground is nothing to be concerned about. If you have digital servos, you're going to get that a lot more...they are constantly working to hold the commanded position, and so use more charge out of the battery pack.

Lnewqban

They look good!

You have done a great thing to prevent flutter of those surfaces.

As others have stated, buzzing due to centering is OK; however, buzzing at full deflection positions should be avoided, mainly because battery overdrain.

Long flying live for your new model!

NJRCFLYER2

My Feedback: (42)

Not meaning to be a wet blanket, but what you have done is add your mass to control surface, which invariably leads to more overshoot when stopping and tends to increase the chance of the control surface oscillating. Static balance of the control surface has practically nothing to do with whether it will be prone to flutter in flight.

BTW, your original concern of the servo buzzing at neutral is normal with digital servos. I'm not familiar with the Futaba 3010, but if it is digital and buzzing a little all the time, it's doing what it's meant to do. Birds gotta fly, bees gotta buzz and so do digital servos. Lose the counterweights and go fly!

cymaz

Hi All

I am not sure if the Futaba 30310 are digital or not. Anyway took the Big Bird ( now renamed as G-WHIZ ) up for a Maiden on Saturday 18 July, perfect weather hardly any wind. Took off like a shot and flew nicely. Only 2 clicks of right aileron needed and 2 clicks of up. Climbs nic and slow turns without dragging its tail round and doesn't want to stall at all, when I finally got her to it must of been the slowest stall of the century,,,,,,,,,,,,,, HOOORAYYYYYYYYYYY.


Both builder and creation are doing well.

Lnewqban

Congratulations, cymaz!!!!