Weird whistleing sound from Solo

makatanav · Oct 3, 2018

Hello guys,

My Solo make weird whistleing sound, and actually strugles to keep position even in in slow winds (I have mRo GPS u-Blox Neo-M8N ).
weird_sound.m4a
I think it's a bearing isue on one of the motors - if three motors, when spinning with arm feels ok, then one is moving heavier and have resistensce like clicks.
Tested all motors in mission planner, there all seems OK.
Already ordered new bearings for all 4 motors

What do you think?

Acroduster · Oct 3, 2018

Have you ever lubricated the motors?

IrishmanPDX · Oct 3, 2018

Sounds like a motor needs replacing alright.

makatanav · Oct 3, 2018

IrishmanPDX said:
Sounds like a motor needs replacing alright.

motor or bearings?

makatanav · Oct 3, 2018

Acroduster said:
Have you ever lubricated the motors?

No, lubricate motors or bearings?

jerryn · Oct 3, 2018

In Tlthe video I shot from my Solo flying at 400ft over a river inlet you can hear whistleling... It is actually caused by the props cutting through a high crosswind.

I will post a video when I get a chance it's pretty cool.

jerryn · Oct 3, 2018

My Solo don't struggle though lol

makatanav · Oct 3, 2018

jerryn said:
In Tlthe video I shot from my Solo flying at 400ft over a river inlet you can hear whistleling... It is actually caused by the props cutting through a high crosswind.

I will post a video when I get a chance it's pretty cool.

that's sounds interesting, OK waiting for video. thanks
in my case, i tried with stock Solo props and also Master Airscrew, 2 different locations and got that sound

Acroduster · Oct 3, 2018

Bearings would be the better bet - they're brushless motors... ;-)

jerryn · Oct 3, 2018

Here's a couple of videos. You can hear the whistle.. it's not bearings

makatanav · Oct 4, 2018

jerryn said:
Here's a couple of videos. You can hear the whistle.. it's not bearings

Yes, the sound is also here, then that’s the wind causing it. Thanks a lot.
I already ordered new bearings, so will exchange them when they arrive (one of the motors have marginally larger resistance), and will balanca all I can balance - drone, motors, propellers

Those who say about lubricating/oiling motors/bearings:
"All bearings that come ready fitted in a brushless motor should be of the shielded type. These will absolutely, definitely, without a shadow of a doubt, come ready-greased from the factory. Greased - not oiled. Without removing the shields "oiling" them can only mean dribbling some light oil onto the outside of the shield. At best, a tiny amount of the oil will get past the shield - at which point all it will achieve is to wash the grease out of the interior. Do that enough times and you'll end up with no grease left in there. The difference between oil and grease is that grease is designed to remain sticky/viscous at high temperatures. Oil, on the other hand, reduces considerably in viscosity as it heats - therefore oil is only effective if the part in question is sitting in a bath of it or the oil is pumped over the moving parts continuously (as happens inside a car engine, for example)."

jerryn · Oct 4, 2018

I have flown my Solo in 50 knot winds with no prolems. I will look for the footage, the whistle is even louder.

Didzis ( Diddy boy ) · Oct 4, 2018

In Solex turn on each motor one by one and take a look at the issued motor if motors bearing

makatanav · Oct 4, 2018

Didzis ( Diddy boy ) said:
In Solex turn on each motor one by one and take a look at the issued motor if motors bearing

I`m on IOS.
But already checked in MP, one by on @ 50% - no such sound

timgilley · Oct 7, 2018

I get the whistling sound when flying at 'high' speeds of 20+mph. Likely the air flow over the GoPro is causing the noise. I have noticed flying sideways I do not hear the noise.

makatanav · Oct 8, 2018

timgilley said:
I get the whistling sound when flying at 'high' speeds of 20+mph. Likely the air flow over the GoPro is causing the noise. I have noticed flying sideways I do not hear the noise.

tahnks for a reply, will try to test this out

RichWest · Oct 8, 2018

My theory is that the whistling problem relates to the GPS cover and forward motion. The cover acts as a reed vibrating as the wind passes around or underneath.

In my application I have rubber tape supporting the hdmi cable. I pinch it between the body and the battery tray, to float the hdmi cable off the gimbal. I tuck the tape's tail under the GPS cover, which must act as an air dam or a damper to the cover. My bird no whistle anymore....

You can test the theory, apply some tape to overlap the gps cover and the body at their intersection at the front.

Just my 2 cents...good luck.

makatanav · Oct 9, 2018

RichWest said:
My theory is that the whistling problem relates to the GPS cover and forward motion. The cover acts as a reed vibrating as the wind passes around or underneath.

In my application I have rubber tape supporting the hdmi cable. I pinch it between the body and the battery tray, to float the hdmi cable off the gimbal. I tuck the tape's tail under the GPS cover, which must act as an air dam or a damper to the cover. My bird no whistle anymore....

You can test the theory, apply some tape to overlap the gps cover and the body at their intersection at the front.

Just my 2 cents...good luck.

thanks for your 2 cents, will test this "apply some tape to overlap the gps cover and the body at their intersection at the front "
Maybe you can throw in some pictures how it looks?
I have hdmi replaced to flat cable already.
And the noise is actually heared simply hovering in the ir and no metter what dirrection I turn the drone.
Received bearings yesterday, will try to exchange till weakend and inform back

RichWest · Oct 9, 2018

If hovering, the sound is likely the ESC's chirping as they correct orientation for level flight. If truly a bearing, then swap them out immediately...

From the following link is a video depicting the rubber tape holding up the hdmi cable. You can see the tail being held by painter's tape to the front of the body...

Macro vibe reduction?