Hei.

So i just bought my Phantom 3 this week and im in love with it. I got some amazing 4k clips of my city and many more will come in the future.

But in the last days i have noticed something strange. When the engines are armed the arms starts to shake a lot when it's idling. I do not notice the shake on the camera when im flying so i don't know if it's shaking in the air. I have tried to change the props and checked for any damage on the props and the phantom.

When i run the phantom without the props i can't se any vibrations on the engines themself or on the aircraft.

Anyone had the same problem?


Here is a link that shows the problem.

That does not look normal, when ever I armed the engines on my p3a it does not do that. What FW do you have btw?

I know :/ I got the latest FW since i had to install it before i could use the drone.

That isn't right. No crash no big bump? Did you check to see if the screws are tight below?

Take your props off and see if it still shakes
if no try another set of props

I did try to change one prop at at time to see if one of them was damaged but the vibrations did not stop. Than i did try to remove one prop at at time and when i did remove one of the black props the vibrations did stop. It didn't matter which one i did remove.

I find this very strange O.o

digitaldave Posted at 2015-6-27 04:10
That isn't right. No crash no big bump? Did you check to see if the screws are tight below?

No, the only bump i got was at the second flight after i got it where the instructions said to hold both sticks down to turn of the engines. I did hit the stairs just a bit with one prop, but no damages on the props or craft.



You can se what happens when i remove one of the props.

^                 

Well the fact that it doesn't do it without the prop is easily explained. The resistance of the prop is going to make the vibration worse, so it seems the motor is unbalanced not the props.
You say you cut the engines and hit the stairs? Was it like you were about to hit the stairs in flight and then cut the engines so it fell? Or was it on the ground and just fell over on landing?  The motors are pretty finely tuned and they are screwed into plastic so even a small bump in just the right place could cause the motor to unseat or twist without you seeing any visual damage. You didn't mention if you checked the screws but I would remove them and look inside and around where the motor seats. If there is anything bent or looking odd or different to you compared to other motor cavities then that would be your problem. Take notice that all the motors are at a specific angle. any change in that will cause residual vibrations.

I understand that, but if one engine was unbalanced the vibration would disappear if i removed the prop on that engine, but in my case i does not matter which black prop i remove. Once one of the two is removed than the vibrations stops.

I have checked the screws and there was nothing wrong. I also lifted out the engine just to check it and found nothing wrong.

About the "crash" i had landed the drone and was going to stop the engines. I followed the manual (that is wrong...) and pulled both sticks down. Than the craft tilted and drifted towards the stair (still on the ground) and one of the props did hit the stairs just a bit.

If one engine is damaged, you would have vibration with or without props. Worse with I would imagine.

bump! Is nobody from DJI reading the forum?

It would be nice to get a little help from DJI.

It appears as vibration due to resonance in which the motors works together. if you don`t see vibration on video when flying, I think this is normal.
but do not hold on for a long time idling, because the vibration leads to deformation

you can check the temperature of the motors after work. if any motor is much hotter others, the more likely it is defective