Hey guys,

Anyone else had stress cracks appear on their P4P? I've never crashed the bird but today after hand catching I noticed some significant and major stress cracks on 3 of the 4 arms. They all seem to be around the air ducts. The screws near the air ducts also appear to be loose. I've done around 60-100 flights on this bird. I called DJI and they want me to send it back in but because I'm currently travelling Australia for 6 months and the drone is an essential piece of my photography equipment I'm loathed to send it in knowing I probably won't get it back for weeks. Some pics below - note that there's no cracks on the upper part of the shell.

Those look pretty bad.  I would send it back. With cracks like that, it could come apart easily.

how old is your phantom? I'm already worried about mine
have you already looked for a service center where you are ?
I'm in Italy and here the assistance worked very well ...
even if my phantom 4P was sent to Holland ... everything was great ...
let us know how it ends ...
crossed fingers friend

AlexVideoShark 5 Posted at 2018-2-26 04:48
how old is your phantom? I'm already worried about mine
have you already looked for a service center where you are ?
I'm in Italy and here the assistance worked very well ...

It's around 4 months old. I know European support are pretty quick because I've had some kit serviced there before and they really try hard to get it back to you ASAP especially if you need it for work. Australia on the other hand have been pretty bad so I'm loathed to send it in. I'm tempted to use some duct tape until we finish our trip. I can't be without the bird for too long - it's an essential part of my work kit while travelling.

Thanks for your kindly reply...
I agree with you ... never too long without....
just ... if you can ... please ... let me know how it end ...

I just received my p4p (replacement ) back from dji repair. Also noticed after updating fw .300 , 2 stresscracks at airvent of the arms. I also noticed after update latest fw , big vibration of engine arms upon take off, throttle half up.i downgraded fw back to .602 fw. Shaking is gone. My p4p was 8 months old , and under warranty. Also sent to dji netherlands. It took 1.5 week to sent me the replacement. Check when received back of different serialnumber

Btw there have been several reports regarding stresscracks and vibration after the latest fw

dronybaloney Posted at 2018-2-26 05:34
Btw there have been several reports regarding stresscracks and vibration after the latest fw

Yeh I'm running the beta and the flight characteristics are pretty bad if I'm honest - very shaky and unstable.

That's brutal.  Perhaps you can at least tape it up to prevent them from propagating further.

Are you flying the latest firmware? Because I'm really worry about the vibrations it is causing to the aircraft.

Use strong tape ... but send it for replacement as soon as possible!

I have a regular P4 and I just noticed today that I have a crack forming in pretty much exact same spot as yours.

Reminds me of the de Havilland Comet square windows fiasco.

I had stress cracks in my p4p+ on the air vents , it was 6mths old and had done 20hrs and 180000 mtrs  . i had not updated to the  latest fw with  the vibration issue so i think  the cracks were age related ?
I managed to get a full refund  under Uk sales regs and have bought another p4p+  , time will tell if it goes the same way  ?( it has fw with the vibration ) .

Well, This is now something that I will have to look at in my regular inspections.

I can see there is a allen screw in that hole there. Ill be checking them to see if they get loose over time.
How much does anyone want to bet that those screws are loosening themselves with the torsion of flight. DJI if you are listening, you might want to start using a little lock tight. Or using a pin on a eye bolt, or wire tied bolt.

Wow.  That is bad.  I haven't flown as much as you.  Its been too cold and windy but after seeing this post I looked and there are not any cracks yet in mine.  Just to clarify, did you notice the loose screws after finding the cracks or before?  Just trying to understand if the loose screw is the root cause, a contributing cause or the symptom.  I guess regardless I need to check the arms and screws regularly.  Thanks for posting this.  I was not aware that this was a problem.

IamWedge Posted at 2018-2-26 17:53
[view_image] I can see there is a allen screw in that hole there. Ill be checking them to see if they get loose over time.
How much does anyone want to bet that those screws are loosening themselves with the torsion of flight. DJI if you are listening, you might want to start using a little lock tight. Or using a pin on a eye bolt, or wire tied bolt.

My screws are loose and my motors are flexing and moving with very little force. The screws also seem like they're loose but that's probably because the entire frame is compromised. I'm sending my bird back - it's not safe to fly.

So anyone know what size allen this is? Ill have to add one to my kit.

I think 2mm.

How about p4 advance? Have not heard Abt crack. Maybe because of less update fw?

All I know is that I never had any cracks appear on my P4 after maybe 500 flights over a year.

gyrex Posted at 2018-2-27 03:10
My screws are loose and my motors are flexing and moving with very little force. The screws also seem like they're loose but that's probably because the entire frame is compromised. I'm sending my bird back - it's not safe to fly.

Hi, gyrex, we are so sorry for the trouble that has been caused to your travel, for the safety, please send in at your earliest convenience and our repair center will take care of it for you, please keep us updated if you need assistance during this process.

Send it back before it falls out of the sky those cracks are very bad

Well, as usual, the DJI support centre in Australia are dragging their feet and I'm still waiting for my drone to come back. They've had my drone for 1.5 weeks and still haven't shipped it. The Australian repair centre is a joke!

Thanks for sharing, those cracks are shocking, for sure a design flaw being exposed by latest firmware's.  

My P4P has done the same thing today, calling them tomorrow. Hope they get you fixed soon.

Okie Posted at 2018-3-24 19:24
My P4P has done the same thing today, calling them tomorrow. Hope they get you fixed soon.

If you're in Australia, be prepared to wait 3 weeks for a repair. The Australian repair centre is a joke.

Can I ask, how do you store and transport your bird?

Genghis9 Posted at 2018-3-24 20:04
Can I ask, how do you store and transport your bird?

I carry mine in a custom backpack with foam separations etc. The cracks didn't appear during transport and it's the same backpack I used for 12 months with my P4 which had zero cracks appear.

How's it going, getting it sorted?

gyrex Posted at 2018-3-24 22:42
I carry mine in a custom backpack with foam separations etc. The cracks didn't appear during transport and it's the same backpack I used for 12 months with my P4 which had zero cracks appear.

Thanks
Was the bird exposed to any high heat, say over 90 degrees F?
So you know, I believe DJI uses substandard plastics in their shells, but it's the QC process that is truly lacking which likely accounts for why some batches are ok but others are not.  In your case I've never seen "stress" cracks so bad and so many at the same time so I'm wondering if there were any contributing factors that accelerated the process or made them worse.

Genghis9 Posted at 2018-3-25 02:23
Thanks
Was the bird exposed to any high heat, say over 90 degrees F?
So you know, I believe DJI uses substandard plastics in their shells, but it's the QC process that is truly lacking which likely accounts for why some batches are ok but others are not.  In your case I've never seen "stress" cracks so bad and so many at the same time so I'm wondering if there were any contributing factors that accelerated the process or made them worse.

All plastic airframes will crack at some point. There's a reason why real aircrafts use the highest level of alloys and composites and results to a pretty lengthy lifespan. Plastic is light weight but as an airframe, prepare for cracks because it cycles for every flight. How long till it occurs depends on usage and environment.

But one solution that would work is to spray line x coating or an alternative on the inside of the plastic arms. Have to strip before doing so though

djiuser_dFXv88EjMq36 Posted at 2018-3-25 04:05
All plastic airframes will crack at some point. There's a reason why real aircrafts use the highest level of alloys and composites and results to a pretty lengthy lifespan. Plastic is light weight but as an airframe, prepare for cracks because it cycles for every flight. How long till it occurs depends on usage and environment.

But one solution that would work is to spray line x coating or an alternative on the inside of the plastic arms. Have to strip before doing so though

Line x coating ? not heard of that before ,could you give more  details in the way it works and is applied etc .
thanks .

Again, there seems to be some correlation (real or implied) with the cracks and the vibration observed after the last one or two FW updates.   I think one thing for sure is the motor arms are weak and not up to the task.  Added stresses from vibration and/or aggressive flying styles appear to possibly precipitate the failures.   I am holding off on that last series of FW updates until at least the vibration issue is addressed.   

Anokadrone Posted at 2018-3-25 05:56
Again, there seems to be some correlation (real or implied) with the cracks and the vibration observed after the last one or two FW updates.   I think one thing for sure is the motor arms are weak and not up to the task.  Added stresses from vibration and/or aggressive flying styles appear to possibly precipitate the failures.   I am holding off on that last series of FW updates until at least the vibration issue is addressed.

I'd tend to agree with your theory. I'd also say that those large ESC vents and the narrow pieces of plastic surrounding them compound the issue. This is definitely a weak spot on the craft as there appear to be plenty of others who've had cracks appear in the same spot. I never had these issues on my P4 over 12 months with hundreds of flights recorded.

I am wondering, if this is just plastic, why does the product page state: ''The adoption of titanium alloy and magnesium alloy construction increases the rigidity of the airframe'', is the shell not a part of the airframe?

Did you get it solved gyrex, if so how long did you have to be without it?

KedDK Posted at 2018-3-26 01:09
I am wondering, if this is just plastic, why does the product page state: ''The adoption of titanium alloy and magnesium alloy construction increases the rigidity of the airframe'', is the shell not a part of the airframe?

Did you get it solved gyrex, if so how long did you have to be without it?

The frame which everything attaches to (including the plastic) is some kind of alloy but the shell is just plastic.

DJI's Australian repair centre took 3 weeks to 'repair' it. ie. send me back a replacement craft. No, I'm not joking... DJI's post sales support continues to be worst in class.

Resurrecting this thread, as my P4P has these same stress cracks on all 4 arms now after maybe 30 flights. The problem, though, is obviously faulty design - the motors are hard mounted to the airframe with no shock mounting. Compounding it is the super stiff and inflexible shell and arms. Anything that spins a prop has to have some form of "give" in the mount; vibration and Coriolis force, etc., has to go somewhere if there isn't something to absorb it in the installation. All you folks familiar with full scale aircraft design know what I mean.

The cracks are a kind of "built-in" shock mounting that sort of developed by themselves, I guess you might say.

Might be an opportunity for a 3rd party to develop a soft mount for the motors on the P4 series? I'm thinking about something myself, but mine is already damaged and wouldn't be a useable test bed....

luciens Posted at 2018-6-30 09:59
Resurrecting this thread, as my P4P has these same stress cracks on all 4 arms now after maybe 30 flights. The problem, though, is obviously faulty design - the motors are hard mounted to the airframe with no shock mounting. Compounding it is the super stiff and inflexible shell and arms. Anything that spins a prop has to have some form of "give" in the mount; vibration and Coriolis force, etc., has to go somewhere if there isn't something to absorb it in the installation. All you folks familiar with full scale aircraft design know what I mean.

The cracks are a kind of "built-in" shock mounting that sort of developed by themselves, I guess you might say.

Did all these cracks appear after one specific flight or over time?
I keep thinking there are some bad batches out there.
Some people report major cracks, others nothing.

It would make sense if most people report cracks after a certain mileage. But that's not the case.
Some people treat their drone like a raw egg and get these. I have abused my P4P a lot and still after more than 1000km: Nothing.
I'm wondering if there is only one production facility for these drones - in China - or if they get produced worldwide at different facilities.