Drunk Phantom 3 Advanced

[Luis Portugal]

Hi all

Yesterday I sent my P3A on a 4.5km run over the ocean and was fighting strong wind on the way back. The result was that it self-landed (fortunately already on land) once it reached 10% battery. I was able to recover it but I think it clipped a roof with a prop and fell on a nearby pile of sand -- since it was covered in sand in places -- before careering to the middle of a front porch where I found it upside down.

There are no cracks or dents and no visible physical damage (apart from a broken prop which I've replaced) but now it won't steadily hover in place any more and sporadically jerks, mostly to the left, like a drunk drone.

It could be the vission positioning module (vpm) that's broken -- I haven't gone high enough to see if it's stable where the vpm won't work -- but I'm suspecting a damaged gyro. Gimbal and controllers all seem fine.

Is there any way to do some diagnostics to see what bits and pieces (if any) I need to buy in order to heal my Phantom?

Kind Regards,
Luis

 

[Scozz76]

Have you cleaned out all the sand?

 

[louforgiveno]

Hi all

Yesterday I sent my P3A on a 4.5km run over the ocean and was fighting strong wind on the way back. The result was that it self-landed (fortunately already on land) once it reached 10% battery. I was able to recover it but I think it clipped a roof with a prop and fell on a nearby pile of sand -- since it was covered in sand in places -- before careering to the middle of a front porch where I found it upside down.

There are no cracks or dents and no visible physical damage (apart from a broken prop which I've replaced) but now it won't steadily hover in place any more and sporadically jerks, mostly to the left, like a drunk drone.

It could be the vission positioning module (vpm) that's broken -- I haven't gone high enough to see if it's stable where the vpm won't work -- but I'm suspecting a damaged gyro. Gimbal and controllers all seem fine.

Is there any way to do some diagnostics to see what bits and pieces (if any) I need to buy in order to heal my Phantom?

Kind Regards,
Luis

You may have a failing motor bearing or sand in a motor.....try hand spinning each motor and listen for a motor or 2 not sounding or spinning the same as the others.... use a vacuum attachment hose to vac out each motor at the very least.

 

[Reed L]

You said you replaced the prop, you should replace them all with a new set. It sounds like you may have cracked a motor mount or as mentioned above, a bad bearing probably on the motor that lost the prop. Take the top off and check the mount as well.

 

[happydays]

Also a calibration of the IMU would do no harm.

 

[Waylander]

You said you replaced the prop, you should replace them all with a new set. It sounds like you may have cracked a motor mount or as mentioned above, a bad bearing probably on the motor that lost the prop. Take the top off and check the mount as well.

Hi I had a similar problem with a P2 I opened it up and found that the "c" clip had popped off from the bottom of one of the motor's Rotor shaft, allowing excessive vertical movement of the Rotor, the clip is very small and it could have dropped out of the casing, you might need to check each motor especially the one with the damaged prop
Good luck
Waylander

 

[Luis Portugal]

Hi folks.

Thanks for all your sugestions and very quick replies.
I set the vaccuum on my Phantom, calibrated the IMU and I had already replaced the entire set of props (sorry I didn't mention that). It's still jerky when it hovers.

So, I replaced the 3 beat-up blades which were still whole and added one more from the original set (which has also been severely punished)...

IT WORKS!!!

The new blades (on the right in the photos below*, compared to a DJI original on the left) look very similar to the originals but are a set I bought on e-bay. The new ones are a bit shinier, seem a little more brittle and less ruberry than the DJI blades, albeit identical in size, weight and shape. So I considered that maybe their dynamic properties were what was causing the instability and it appears that was the cause.

* Yes. The unstable new blades have already sent the Phantom crashing into a wall and turned it belly-up once. Hence the scratches.

My Phantom seems to be its old self again. I just need to get a new set of original props. Now.

If enough people think it's worth it, and request it here, I can make a Youtube video and post a link here to show the difference in performance.

Cheers,
Luis

 

[eBird]

Hi all

Yesterday I sent my P3A on a 4.5km run over the ocean and was fighting strong wind on the way back. The result was that it self-landed (fortunately already on land) once it reached 10% battery. I was able to recover it but I think it clipped a roof with a prop and fell on a nearby pile of sand -- since it was covered in sand in places -- before careering to the middle of a front porch where I found it upside down.

So you flew too far and ended up crashing on someone's front porch? Oh my. Not good for the hobby. Hope you get it working again and fly a little more carefully.

 

[Luis Portugal]

So you flew too far and ended up crashing on someone's front porch? Oh my. Not good for the hobby. Hope you get it working again and fly a little more carefully.

I've been 5.2km out on a previous occasion -- to film ships anchored off-shore -- and made it back safely. The wind was just a little too strong this time. I started my return trip with 70% battery but was flying back at 6m/s at times (while flying out had been at up to 15-17m/s).

But I get your point; we don't want to stoke up fears in the community of drones falling out of the sky, which is why I do most of my flying over the ocean. I get enough brow-beating from a neighbor of mine who works at the national airport and gets plenty of grief from rogue UAVs (and even a model zepplin once) crossing the runways. All very far away from me.

But fear not, the landing was at an acquaintence's house (the Phantom can still be controlled on its X and Y axis as it's going down for its emergency descent) but the crash was unfortunate and I've since identified an obstacle-free abandoned dirt patch right next to the water for emergency landings. I just have to make sure I get there begore anyone else does.

In my experience UAVs do spook a lot of folks and annoy others, though... so I think we are all wise to keep that in mind.

 

[eBird]

Well, good the "landing" was at an acquaintance's house
I know the sick feeling of trying to get back with that low battery alarm going off, happened to me just once, was out 2000 feet and 600 feet up in a deep canyon, and didn't realize battery was at 33%. Hauled butt home and still had 22% once I landed, but that was kinda scary.