Can someone please tell me if this is normal? I am noticing visible vibrations in the motor mounts / booms of my brand new I2 with X4S camera.
The vibrations occur intermittently. Usually they appear after hovering in one spot for a few seconds. The resulting gimbal footage does not appear to be affected.
Additionally, there is a metallic chiping sound which is audible in the above video, but is clearer in the below video:
I have tested the following:
1. Booms do not have any play or movement.
2. Motor mounts have no play or movement.
3. T Joint is secure
4. Transforming support arm is secure
5. Transformation centre point has some very slight movement when in landing mode, however when in flight mode, this movement disappears and the centre point is solid.
6. Rear left motor exhibits a very slight movement when wiggled by hand. A gentle ‘click’ is felt through the motor housing. The other motors do not exhibit this behaviour.
7. All propellers exhibit some play in the snap-lock motor mount. This results in approx. 3mm of deflection at the end of the prop.
8. Firmware which the drone shipped with: V01.01.0010-
9. Performing a ‘reset to factory default’ using DJI Assistant had no effect on the problem.
10. Upgrading firmware to V01.01.0200 had no effect on the problem.
Flight testing
1. The vibrations seem to be apparent at altitudes between 0.5m and 4m. Beyond this height it is difficult to see if the problem persists.
2. The vibrations appear to continue in directional flight, though diminished slightly - not sure if this is simply because they’re more difficult to see on a moving subject.
3. Replacing the propellors with a new set has no effect. For the remainder of these tests, the original props were used.
4. Switching the visual positioning system off has no effect.
5. Switching to S mode has no effect.
6. Switching to A mode appears to reduce the frequency of the problem significantly, however when it occurs it is with the same severity.
7. Switching to landing mode appears to eliminate the problem, even in P mode.
8. When spinning up motors on the bench with no props, they appear to spin true, and there are no odd noises.
If there are any other I2 owners out there with the X4S I would really like to hear from you regarding this.
Couple of things to try. Turn off the VPS and see if it steadies the hover near the ground as you say it seems better on landing with the gear down. Maybe try a VPS calibration too.
When I installed GO 4.1.8 my RC sticks were overly sensitive until I did that calibration a few times. I could barley touch one and it would barely move the blue line, and then it would shoot to 100% quick. I also like to make a circle while calibrating to see how smoothly they go to 100%. Afterwards, it smoothed out a lot.
Another is find the supplies to balance your props to check on the wobble part of the motors. DuBro makes a balancer, but you need to Google eBay for the shaft that fits the I2 props which is about $19 as I recall. Two of mine were heavy when new.
Your prop tip deflection doesn't seem excessive, but you could try the CA glue trick under the props to tighten them up. I used the CA Medium and mine tightened up pretty well. I may have gotten away with the CA Thick on one, but it seems okay.
I have the X4S as well as the X5S. The lower gimbal mount has a little bit of vibration felt with my finger (Top plate by the VPS camera is rock steady.), but the X5S has a lot more in comparison. Likely the gimbal motors in the X5S are doing more work contributing to it.
Thanks for your reply. I've tried switching off the VPS and it had no effect - see my original post for a list of troubleshooting steps I've undertaken.
I have a dubro prop balancer, however DJI state the props don't need balancing. I will get the adaptor and try anyway.
Since my previous post I have also done the following:
All other aspects of the drone are perfect, so I am beginning to think this occasional vibration is normal, and that others simply haven't noticed it.
I did find that reducing the pitch and roll gains to 95% seems to reduce the vibrations considerably. I haven't been able to find any info on what the gains do, but I am assuming it's similar to adjusting P in PIDs on Arducopter.
My theory is that this is a flight controller issue - the FC gets into some kind of feedback loop which results in a harmonic vibration. This explains why the issue goes away in A mode.
Why theorises what happened given that you do not have any DJI product engineering knowledge? You have bought a fine product from a reputable company. That is job customer service to help you to resolve any issues with using their products.
doble Posted at 2017-12-11 21:02
Thanks for your reply. I've tried switching off the VPS and it had no effect - see my original post for a list of troubleshooting steps I've undertaken.
I have a dubro prop balancer, however DJI state the props don't need balancing. I will get the adaptor and try anyway.
Hi, sir. I would recommend you check if the motor of your I2 loose or not. Please ensure that the props are not broken and the propeller mounting plate works well. Keep us updated, thanks a lot.
lvl.2
Second Officer
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