Whistling noise

[Newbieguy]

I'm getting a high pitched whistling noise from my P3S. It just started after 2.5 hours of flight time. It wasn't present before. All of the research I've did is all over the place from a nicked prop to bearing failure, the majority said it was normal. The temp on all motors feel the same. When it was idling on the ground I did notice one prop seemed to be rotating slower than the others. Any thoughts or feedback on this high pitched whistle would be greatly appreciated. Thanks.

 

[Phantom2USA]

I've a Phantom 2 vision plus that has a very slight whine on throttle up after hover. If I keep it I'll do the bearing upgrade..
Change & balance props & test.. Eliminate that possibility..

 

[Phantom2USA]

I've got an extra "Du bro" prop balancing rod if ya need one, (rod only) pay the shipping.. pm me if interest..

 

[120CCPM]

Excluding the props from the equation is pretty simple: change them all, and see if the noise goes away.
If it doesn't, try to spin the motors by hand, one by one, using approx the same force, and see if one consistently stops sooner than the others. If not, it could be just normal bearing noise. A small drop of light oil in the right place might actually help a lot, even if there are some with a very strong opinion against that.

 

[Newbieguy]

I removed the props and I still have the whistle. The motors seem to all turn with the same resistance. Now I'm paranoid.

 

[epicdoom]

I've noticed a time or two that one prop wasn't spinning as fast as the others. I found it was because I wasn't sitting on level ground looked fairly level but wasn't. so after some thought on it I found it to be the Gyro compensating for the non level condition confirmed this by sitting my AC on a concrete pad that I leveled off for my Grill. once on that all props appear to be spinning the same speed. Could be that's why it looked slower in your case also. as for the Noise I hear the props spinning in unison as one harmonized sound that does sound somewhat like a whine. When the drone is in the air slight input in any direction other then UP will disturb that harmony. I learned to listen to and for that harmonized sound when flying twin motor Differential thrust planes I would set trim till both motors noise became one harmonized note and I knew then I was near perfectly trimmed for level flight on differential thrust twin motor planes.

 

[Newbieguy]

This is a new noise for sure. It just started on the morning flight. A very high pitched whistle.

 

[epicdoom]

I've not heard anything like that on mine Brother, if its doing it without the props attached Id think it would have to be a motor or motors electrical noise whines but I've never heard it Whistle are all motors tight ? all motor top bells ( the part the prop attaches to ) secure? try to determine is any wiggle more then another look inside the openings and slowly rotate them to make sure nothing is in there

 

[Newbieguy]

 

[Newbieguy]

It sounds just like this. Nothing seems loose and I don't see any debris anywhere.

 

[Gryphon]

Mine had developed the same whistle noise shortly after the first few flights. I have checked everything and searched the threads here below. I have not found it to be anything that seems to be on it's way out. It was disturbing to say the least though when it started.

 

[epicdoom]

maybe my audio isn't picking up, but it sounds like it should to me

 

[Newbieguy]

I flew for 20 mins and no hot motor.

 

[epicdoom]

Id keep it close for a bit just to keep an eye on things for a bit if you have a temp gun you can see what the motor temps are after a full battery my are usually around 70-90* F depending on how hard I run it. the video you posted it sounds healthy to me and no different then mine sounds, buts its not always easy to capture sound as its produced and even harder sometimes for it to sound the same on every player. I learned this when I started getting into suppressed weapons builds. What I hear with my ears I don't hear when recorded.

 

[Newbieguy]

The main concern that I have is the noise didn't start until after 2.5 hours of flight time. I don't like new noises.

 

[FLOATIN]

If it was a motor problem I would expect the problem motor to stop spinning, when powered off, sooner than the others. Have you tried replacing the propellers?

 

[Newbieguy]

I switched props. While on the ground at an idle I noticed one prop seemed to be moving at a slower rate of speed.

 

[FLOATIN]

That might be your bad motor.

 

[Cruck]

Thats how they sound. Sounds identical to mine.

 

[120CCPM]

I switched props. While on the ground at an idle I noticed one prop seemed to be moving at a slower rate of speed.

That's not a conclusive test. Spin them by hand using the same force a few times, and see if one consistently stops sooner or makes a different noise than the others. Also, check motor temperatures after a flight and see if one motor is hotter than the others. Motor bearings could be noisy from the factory because of tolerances and lack of lubricant, or can become noisy with use. As I said, in the RC world many people lube them regularly with a small drop of light oil properly positioned between the inner race and the shield (which, before anyone says you can't lube bearings because they are "sealed", it's just a shield and not a seal). I've never done it on my P3S as so far it's been pretty quiet, but I believe on the latest motors you can only reach the lower bearing as the upper one is completely hidden by the motor bell... but don't quote me on this as I'm not near my AC.