99GrandTouring

Well I just put my drop box on my xtra easy for tomorrow, and the servo in it growls?
It is a old servo but it is brand new.. (meaning I purchased it a long time ago and am just now opening it and using it)
It is an Tower hobbies servo with airtronics plug, I have a airtronics-jr connector adapater.....
no matter what way I set it up it growls, there is no tension on it or anything??
What could this be? a bad servo?
Will this cause a problem with flight?
Thanks!

Fire_fly321

I had that problem a while back with a Futaba servo. It was not new. It was about 5 or 6 years old. If you take the servo apart, in the top of it you will find a mess of plastic gears that are all intertwined. Originally there is a small amount of lithium grease for lubrication. Over time with use this grease can get "slung" off to the sides. When this happened I just regreased the gears with new grease and the grinding noise went away.

Specific to your question, I'm not sure because there is not much use involved. I suppose it's possible that the gear grease aged to the point where it isn't lubing properly.

To answer the second part of your question, I don't think that it will affect the flight of your plane other than the battery life. The increased friction from the grinding is definitely using more juice than normal.

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99GrandTouring

well its not a grinding as in when it moves, when it moves its smooth/quite...
Its making the sound like if you try to grab a servo arm and move it, the servo vibrates and resists you trying to force the arm in the opposite direction...
sorta like its binding....

Flypaper 2

Some new servos will do this. When they get used for a while, they quit. Also a control surface with quite a weight to it will cause the servo to hum. Try disconnecting the pushrod from the servo and see if it does it. With the pushrod disconnected, move the pushrod back and forth by hand to see how much load is on it. Let us know what you find. Could help other people with the same problem.

Lancair-RCU

Ive just had the same problem with two JR 537 (I know cheap) servo's Ive just installed in a new model. They worked fine in their previous ride. After removing the linkages they still growled away constantly. What I found was, Ive used new Multiplex servo horns (same spline count), the shaft depth is deeper, so by screwing them on to the servo, the inside of the arm spline case itself was creating pressure against the servo casing, causing a load and therefore the growling noise. After backing off the screw and releasing the arm from touching the case they're quiet as a church mouse again. Tomorrow (its 12.45am here now) Ill take them off and sand down the arm so they can be screwed on tight and not bind.
Just thought Id post this possible solution here for others. (I read this thread earlier today) Ive read elsewhere that servos constantly growling away is a good way to burn out the potentiometer quickly, therefore wrecking the servo permanently.

Lancair

malthepal

My Feedback: (1)

I have the same problem with one of the servos as it sits in the box with my new JR transmitter. It almost seems as if it is searching for a neutral position but cant find it. It truly growls, or grumbles. But only the one servo.

adam d

same with my hitec trotel survo but after a wile it stoped

phread59

99 trying to force the servo arm with the radio on will cause this. It is normal, the servo is trying to retain the position the radio is telling it to. If it is doing this just sitting there. There is likely some binding in the push-rod or the control surface. You may need to move the clevis's to zero out the contol surface. Good luck.

Mark Shuman

99GrandTouring

I know its an old post, but I just finally got out of school and moved so I'm back into flying again and sure enough they still growl, same plane, same servos, just setting there.
I'm gonna try loosening the screws to the arms see if it helps

The Ghost

The feed back pot in the servo will be dirty or not bedded in as the servo is an old one(sitting long time) a small amount of bulid up on the carbon track of the pot is likley to be not letteing the wiper to contact cleanly.

Cheers.

APIA

Two things can contribute to this, First off, if your transmitter antenna is not fully extended this will sometimes happen, additionally, it is not good for Futaba transmitters to transmit with the antenna down. Secondly, freshly charged batteries will exhibit the same thing, leave the receiver battery on for about 5 minutes and the problem will probably go away.
-Tom