Bad Bearing Diagnosis

[rocjock]

Hey guys.
After reading about bearing replacement on here and having my copter in some harsh conditions I want to change some bearings.

I'm still trying to figure out exactly how to diagnose bearings that need to be changed. I do have a video below of a motor of mine that is making some harsh sounds. Unfortunately, it is a brand new motor with 1 flight. I had just balanced all the motors and this one stood out as it sounded harsh and considerably different then the rest.

make sure your sound is Not full blast when you start this video. http://www.youtube.com/watch?v=guK78r5WEzE&feature=youtu.be

is that the sound of bad bearings? i'm squeezing the frame to make sure it's not some vibrations causing the sound. the bottom motor does not produce the same noise. furthermore, the motor is actually well balanced and not producing too many vibrations according to the seismometer.

thanks

 

[rocjock]

bump. people talk about bad bearings alot. can anyone help diagnose one?

 

[Bartman]

bump. people talk about bad bearings alot. can anyone help diagnose one?

try holding the arm lightly with your fingertips out of the way of the propeller......spin the prop with your other hand and see if you feel anything different from the other motors/arms. sometimes the bearings have to be swapped out because of a prop impacting something less moveable than air molecules....it causes the bearing races to bend and the soon start making noise. other times, a little dirt or something gets in there and they'll start making noise. i don't think is usually a bad bearing but it's more work to clean and regrease a bearing (if you can get it out without damaging it) than it is to just replace it.

bart

 

[rocjock]

ok. a little bit of help if y'all could. just replaced all 6 2814-11 bearings. i did it with Bart's tool and it's very easy. i can't imagine i did anything wrong.

but... i swear 3 of the bearings, 1 for sure, is bad. i've posted a short video. what's with the sound?



<iframe width="640" height="360" src="//www.youtube.com/embed/fqw0qVkUb7k" frameborder="0" allowfullscreen></iframe>

 

[Bartman]

it sounds like you have a little somethin' somethin' inside the motor, remove the motor bell again and take a look inside to make sure there's nothing dragging between the stators and magnets.

 

[rocjock]

thanks Bart.

I cleaned each bell when I initially changed them. I just opened that motor again and all the parts look clear of obstuctions/dirt

Is it ok to fly on that motor? I'm just trying to grasp bad bearings. If they make noise some time so be it... I just want to know if that motor is safe to fly with?

Also, might you point me to where you buy the washers and spring clips?

Thanks

 

[Bartman]

thanks Bart.

I cleaned each bell when I initially changed them. I just opened that motor again and all the parts look clear of obstuctions/dirt

Is it ok to fly on that motor? I'm just trying to grasp bad bearings. If they make noise some time so be it... I just want to know if that motor is safe to fly with?

Also, might you point me to where you buy the washers and spring clips?

Thanks

In that case I'd run it a little, make sure it isn't getting hot and then just keep and eye/ear on it to make sure it isn't getting worse. it will probably break in and the noise will go away. If after a few flights it doesn't then it'll probably be smart to change the bearings in it again.

Are you Steve?

Bart

 

[Bison52]

This thread reminded me of a question I've had. Most replacement bearings come with the caveat that they are grease packed and will have a break in period.

Is there anything noticeable or abnormal during this break in period? Could this be he source of some noise or odd performance on new bearings?

Mike

 

[rocjock]

Thanks for the info Bart. Name is Sean.

 

[Bison52]

Apparently I posted my question at the exact same time Bart was posting his answer. (time stamps) Serendipity.

M