is there somewhere a statistic about motors lifespan? actually they work great but, if I turn them manually, I feel different resistance for each motor, the light click that brushless produces is more or less evident on some motors...I think it's normal because they don't always run at the same speed..

also, has anyone ever noticed the assembly line around each led? it's underneath the paint, seems a crack!!

The motors don't wear out.  It's not something you need to worry about.  Your wings look fine.  Happy New Year

As Mark says, the motors do not wear out, they only have one component that can wear and that is the ball bearing on the shaft, but it is extremely difficult to get to to lubricate.

The bearing is sealed....putting lube in there does nothing but attract dirt......the others are mold lines from the plastic molding.....

Randy

Ok thanks to all.. I knew these motors didn’t have maintenance but maybe a sort of hours limit..so they just die and that’s it then..

Mark The Droner Posted at 1-1 08:33
The motors don't wear out.  It's not something you need to worry about.  Your wings look fine.  Happy New Year

Apart from a hiccup here & there,  they are a sensational piece of equipment IMO.
(I hope I haven't invited Murphy's Law by making that comment )

I mean, I think we all know anything will wear out eventually.  Water dripping on a rock will wear the rock out given enough time.  But in a practical sense, the motors won't wear out because the rest of the drone will wear out first.  Just be sure the motors are clean and there isn't any dirt or sand granules stuck in there (or loose in there that will get stuck in flight) between the copper windings, the outside of the spinning rotors and the magnets causing the motors to lock up.  That's a legit concern.  

Solentlife will post here in a few minutes and explain the motors are not sealed - they are shielded - and I believe he is correct.  I will try to save him the trouble.  

See post #9 here:  https://forum.dji.com/thread-144653-1-1.html

Still - I don't think we've seen any evidence that lubrication attempts do anything as far as longevity.  

in fact, he said sand can create damage..but we can't always land on a clear surface so I don't think is so easy to penetrate the motors considering its turbulence..