One of my motors on my new mavic mini is rougher than the other 3

[Chuanzzz]

Hi guys, I recently flew my drone indoor and my drone drifted and the propeller scratched the walls, but I grabbed the drone as quick as possible to prevent it from actually crashing it. That's when I started inspecting all the parts on my drone. I realised that one of my motor is slightly rougher than the other 3, it's not very very different in roughness, but its noticeable, I tested this by hand turning them back and forth. As you can see in the attached photo,the right, rougher motor, the space between the motor and the actual frame is smaller than the other 3. I just want to ask if anyone mavic mini owners are experiencing this as well, or is this caused by the propeller scratching the wall. I have contacted dji support, they say as long as there is no warning or error in the app should be fine. Thank you in advance for helping me. I have been thinking and worrying all night since this is my new drone and it's only a few days old.

 

[Ajkari]

Im trying to understand what you mean by rougher, is it 1, 2 or 3 in my attached picture?

1. looks like the prop is bent
2. this gap looks smaller than the gap on 3.
but i doubt that the difference in 2 and 3 would make your MM drift.


edit: removed duplicate image

 

[Chuanzzz]

Yeah I meant the gap on 2 is smaller than gap on 3, and also the motor on 2 has higher turning resistance than other motors, altho not a big difference but noticeable

 

[Ajkari]

Try to blow and see if there is any spec or dust stuck inbetween, but I dont think that the gap should make any difference. Regarding bottom left motor turning faster than the others sounds really strange, if you can record it or so then I think its a DJI error. They might hit you back with that you need to calibrate or get more GPS signals but just try and calibrate until its rock steady.

 

[Starz]

May want to get some other props too.

 

[Chuanzzz]

Try to blow and see if there is any spec or dust stuck inbetween, but I dont think that the gap should make any difference. Regarding bottom left motor turning faster than the others sounds really strange, if you can record it or so then I think its a DJI error. They might hit you back with that you need to calibrate or get more GPS signals but just try and calibrate until its rock steady.

I am not sure if it turns faster, but I just feel more resistance while hand turning the right motor

 

[Chuanzzz]

May want to get some other props too.

yeah I bought the flymore combo, will swap them to new ones, thank for pointing it out!

 

[m80116]

I am wondering if the hit didn't cause the engine mounts to stretch a bit.

Personally I've already lubricated the spindles in all my Mini's motors. You can feel them turning a bit more freely afterwards.

 

[Ajkari]

I am wondering if the hit didn't cause the engine mounts to stretch a bit.

Personally I've already lubricated the spindles in all my Mini's motors. You can feel them turning a bit more freely afterwards.

Did the lubrication make any noticeable difference?

 

[BushWacker]

I lost a drone in a tree and got it back about a month later, it fell out of the tree and I had my phone number on it and somebody called me. It sat out in the snow for I don't know how long, maybe the entire month. All the motors were stuck at first and wouldn't even spin. I worked them manually, then blew them out with a compressed air can, followed by a light application of silicone lubricant. The drone has been working flawlessly for months now, the first few flights it was erratic until the motors ran for some time. The motors spin freely now with no scratchy resistance. My observation is the motors can get debris in them and you can feel it when you manually spin them, get them cleaned out and lubricated and the "should" work again...

 

[OregonEd]

I am wondering if the hit didn't cause the engine mounts to stretch a bit.

Personally I've already lubricated the spindles in all my Mini's motors. You can feel them turning a bit more freely afterwards.

That might not be a good idea - lubricants collect dust and stuff and will accumulate ?
The MM motors have one bearing and one bushing and are not made to be disassembled.
There are two or more manufacturers of the MM motors and it is common to feel a slight difference in the resistance when rotating the four motors by hand.

 

[RichR]

I wouldn't worry about the gaps too much. On many makes and models of drone the motors are aligned at the factory and take account of the fact that plastic parts like the arms may not be perfectly straight out of the moulding process. So the motors have shims or adjustment in their fixings to compensate for that.
Generally brushless motors do not require lubrication, although their bearings can wear or get damaged over time. If you need to add lubricant it implies dirt or corrosion has already damaged the bearing to some extent. Having said that, they can continue to work for many hours with the lubricant compensating for the original bearing smoothness without issue. Also they can loosen up once they start to warm up.

 

[OregonEd]

I wouldn't worry about the gaps too much. On many makes and models of drone the motors are aligned at the factory and take account of the fact that plastic parts like the arms may not be perfectly straight out of the moulding process. So the motors have shims or adjustment in their fixings to compensate for that.
Generally brushless motors do not require lubrication, although their bearings can wear or get damaged over time. If you need to add lubricant it implies dirt or corrosion has already damaged the bearing to some extent. Having said that, they can continue to work for many hours with the lubricant compensating for the original bearing smoothness without issue. Also they can loosen up once they start to warm up.

The aforementioned bearings are shielded to minimize the contamination from foreign materials. The manufacturer puts some type of lubrification inside before closing the bearing.
Very high quality or lower quality bearings are available for exactly the same location and applications, which determines their useful life.
When a shielded bearing needs to be lubricated its useful life has past. What could happen if/when your drone has a bearing failure? I prefer just replacing a bearing... good and happy flying!