One Motor sounds diffrent/rough

LinusGrane · Aug 6, 2020

Hello, one of my motors sounds a bit more rough when i spin it. It also vibrates a little bit when i run it whiteout props.
I have replaced the bearings but it still sounds the same. I didn't use boca bearings (i have ordered to all the motors but it takes 1 month to ship it to Sweden) so i dont know if that's the problem.

The white damper underneath the motor is damaged and temporary fixed with tape by the previous owner. I don´t know if that has anything to do with the motor...

The motor seems to work fine, and doesn't get hot. But it fells a little bit scary.

Starz · Aug 6, 2020

If you think the motor has a problem, probably shouldn’t fly it.
By spinning each motor(no props)with your fingers, they should all react the same or very similar.
What bearing did you use?

LinusGrane · Aug 7, 2020

i used this bearing. Not the most expensive ones...
I can feel a small radial play in the motor.

Starz · Aug 7, 2020

That one doesn’t show any specs regarding load or rpm rating. That information may be available by containing the source.
Without that info, I would not trust it.

SanCap · Aug 7, 2020

Replace the motor!!!

LinusGrane · Aug 17, 2020

Got the Boca bearings today, but it still sound different... The bearings is the only moving parts, and everything else in the motor is rock solid. Maybe i´m just paranoid...

Starz · Aug 17, 2020

Nothing wrong with being cautious.

LinusGrane · Aug 17, 2020

Feels like the magnets are stronger in the ”odd” motor. Can it be a motor from a different batch?

Starz · Aug 18, 2020

Certainly a possibility.

LinusGrane · Aug 25, 2020

This is how it sounds, the first motor is the odd one fitted whit boca bearings, the other motors all sounds like the second.
It would be good to know if someone who fitted their inspire whit boca bearings can check if it should sound that way.

The Editor · Aug 25, 2020

LinusGrane said:
This is how it sounds, the first motor is the odd one fitted whit boca bearings, the other motors all sounds like the second.
It would be good to know if someone who fitted their inspire whit boca bearings can check if it should sound that way.

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Absolutely nothing wrong or anything to worry about.

Its play in the thrust washer on one motor but well within spec. All thrust washers have a tolerance of some degree.
Doesn't matter how many times you replace or what bearings you put in, it will still be there.

Go ahead and fly and stop worrying.

LinusGrane · Aug 27, 2020

sounds good

but is it the thrust washer even if the play is radial?

The Editor · Sep 3, 2020

LinusGrane said:
sounds good but is it the thrust washer even if the play is radial?

So you're saying that brand new Boca bearings have radial play?? Highly unlikely.
If you are that concerned and are worrying about 'one motor sounding a bit different' you can either change the motor out completely (which will give you crappy DJI bearings again).
Stop worrying about nothing and go and enjoy flying.
Or keep your aircraft permanently grounded and then you have nothing to worry about........other than a lipo fire burning down your house I suppose.