So I have stress cracks under my motor forming on the shell arm, i've read its a known issue due to over tightened screws.
I put in a service request however i'm wondering if this is covered under warranty? I purchased my Phantom Pro 3 In march 2017, so I'm still under 1 year.

I have the same problem!  Amazon offered me only like 379 to send it back after owning it for 5 months - I hope DJI has a better plan!

Hi, guys. Sorry for the inconvienience it causes. If your drone is under warranty, please send it back for repair: http://www.dji.com/support. Thanks for your support.  

DJI Elektra Posted at 2018-1-13 20:18
Hi, guys. Sorry for the inconvienience it causes. If your drone is under warranty, please send it back for repair: http://www.dji.com/support. Thanks for your support.

What is the warranty coverage on this?  I'm still under a year from purchase

senatorkelley Posted at 2018-1-15 06:31
What is the warranty coverage on this?  I'm still under a year from purchase

It will interesting to see if DJI will warranty this. Those are very small in comparison to what I and others have had. This has been talked about a lot for a long time now. Won't get into it again, but search around this forum and you'll find suggestions for helping to prevent these from coming back whether you  get it repaired by DJI or fix it yourself. One of those things most of us live with. Nothing to get to excited about.

RicardoGray Posted at 2018-1-15 06:42
It will interesting to see if DJI will warranty this. Those are very small in comparison to what I and others have had. This has been talked about a lot for a long time now. Won't get into it again, but search around this forum and you'll find suggestions for helping to prevent these from coming back whether you  get it repaired by DJI or fix it yourself. One of those things most of us live with. Nothing to get to excited about.

It is spreading over the course of the season. At first they were very faint and weren't touching, now one is completely going to the next screw. So its a matter of time before the plastic has a complete failure.
My 1 year warranty is up in March so I want to try and get this fixed before that expires. (That's if this is under the 1 year warranty)

When I get it back i'll be sure to loosen the screws a little since DJI loves to make them so tight.

senatorkelley Posted at 2018-1-15 06:48
It is spreading over the course of the season. At first they were very faint and weren't touching, now one is completely going to the next screw. So its a matter of time before the plastic has a complete failure.
My 1 year warranty is up in March so I want to try and get this fixed before that expires. (That's if this is under the 1 year warranty)

Best of luck to you! I understand why you are concerned. Hopefully you can get it repaired for free. In any event I would certainly think about some motor supports to help out. They are cheap and do help.

RicardoGray Posted at 2018-1-15 06:52
Best of luck to you! I understand why you are concerned. Hopefully you can get it repaired for free. In any event I would certainly think about some motor supports to help out. They are cheap and do help.

I have motor mounts on them already, and it didn't stop it. backing the screws off helped the most.

senatorkelley Posted at 2018-1-15 06:59
I have motor mounts on them already, and it didn't stop it. backing the screws off helped the most.

Oh really. Surprised to hear. But yes, if your screws were real tight that wouldn't be helping. I have repaired several P3A and fitted them with new shells and have made the reinforcements a mandatory part of the repairs, and have had 100% success from the cracking. That is the only reason I was suggesting. Of course I am starting with a new shell at that point and not trying to prevent cracking from already existing ones.

RicardoGray Posted at 2018-1-15 07:04
Oh really. Surprised to hear. But yes, if your screws were real tight that wouldn't be helping. I have repaired several P3A and fitted them with new shells and have made the reinforcements a mandatory part of the repairs, and have had 100% success from the cracking. That is the only reason I was suggesting. Of course I am starting with a new shell at that point and not trying to prevent cracking from already existing ones.

Maybe my mounts are not designed well. Which one's do you recommend?

Also the mounts I was using put indents into the plastic, the original photo was the crack before I put the mount's on.  
Hopefully this doesn't cause any issues with DJI. My intent was to prevent the cracks from spreading.

If your quad is still under warranty (which you state it is) I would send it in for repair. (I sent mine in and it was covered by DJI) Once you received it back with a new shell look into a product called Plast-aid. (This is what RicardoGray is hinting, I think?)  There are many videos that show the application to your bird . (once you receive the returned aircraft crack free)

senatorkelley Posted at 2018-1-15 07:47
Also the mounts I was using put indents into the plastic, the original photo was the crack before I put the mount's on.  
Hopefully this doesn't cause any issues with DJI. My intent was to prevent the cracks from spreading.
[view_image]

I would hope that DJI would still warranty this. Don't think those small indentations would cause them to not fix it, but totally their call.
As far as reinforcements, I hate to name brands but since your asking I have used UAB-bits on several occasions. They are white 3-d printed, weigh little to nothing, and last I remember only $7-$8 for a set.

UAV-bits motor reinforcements

The Plast Aid is  also a good repair solution to mend existing cracks, or if you were doing the shell replacement yourself, you could dab a little around the inside of the lower shell around the motor mount area. I use a similar 2-part epoxy to do this for some added support.

Update:
Last week I submitted my drone to DJI repair and a week later its fixed! Very quick turn around for my 2nd warranty fix!

DJI will repair this under warranty! ( wow the bottom shell only costs $8.00? )

Quote Date:        01-24-18
Remarks:        Dear Customer, This product will be covered under warranty. For more information, please visit (http://www.dji.com/service/policy). DJI North America

Item        Quantity        Unit Price（USD）        Total Price（USD）
Phantom 3 Lower Cover Module        1        8.00        8.00
Freight:                        0.00
Total Amount:                        8.00
DJI Care deduction：                        0.00
Total Payment:                        0.00

Well I too had a stress crack that I sent in to the US repair depot. My p3a developed the crack 11 months into the warranty period.  I was told to send it in for warranty.  The aircraft was fixed and returned in good time and I even posted that it went smoothly how happy I was.  That was until I flew it.  After a two minute test flight in the backyard I made my positive post. The next day I went out to a field and flew it out 1.2 kilometers and all went well.  Upon post flight inspection I discovered a larger stress crack than I had sent in for.  I immediately contacted DJI and informed them what happened.  I was told not to worry and they would take care of me.  Several days later I received an email that basically said I was probably an unskilled pilot who had rough landings or some other nonsense.  Basically tough luck as my warranty expired during shipping.  But wait there is more.  I had ordeted a metal mount motor cover kit and upon installation discovered that during the repair they had stripped one of the mounting screws.  I used a little crazy glue on that one.  The very next flight which was longer appeared to have shaky video and upon landing i discovered the camera platform was holding on by 1 screw!!!  At this point i went over every inch of the craft and discovered that there also appears to be some some tiny screws that were not installed in the battery bay.  See pictures.  So from here on in I will do my own repairs for safety sake.  And honestly I am pretty sure this will be my last DJI product.

fans50b43636 Posted at 2018-1-25 08:27
Well I too had a stress crack that I sent in to the US repair depot. My p3a developed the crack 11 months into the warranty period.  I was told to send it in for warranty.  The aircraft was fixed and returned in good time and I even posted that it went smoothly how happy I was.  That was until I flew it.  After a two minute test flight in the backyard I made my positive post. The next day I went out to a field and flew it out 1.2 kilometers and all went well.  Upon post flight inspection I discovered a larger stress crack than I had sent in for.  I immediately contacted DJI and informed them what happened.  I was told not to worry and they would take care of me.  Several days later I received an email that basically said I was probably an unskilled pilot who had rough landings or some other nonsense.  Basically tough luck as my warranty expired during shipping.  But wait there is more.  I had ordeted a metal mount motor cover kit and upon installation discovered that during the repair they had stripped one of the mounting screws.  I used a little crazy glue on that one.  The very next flight which was longer appeared to have shaky video and upon landing i discovered the camera platform was holding on by 1 screw!!!  At this point i went over every inch of the craft and discovered that there also appears to be some some tiny screws that were not installed in the battery bay.  See pictures.  So from here on in I will do my own repairs for safety sake.  And honestly I am pretty sure this will be my last DJI product.

Thanks for sharing! I will definitely check to make sure all screws are on while I untighten the motor mounts to prevent further cracks.

I was cleaning some bugs off my phantom 3 pro and noticed really bad stress cracks under one motor.  Called DJI and no help out of warranty. Asked for supervisor and was put on hold after being told over and over that a supervisor would not help.   I explained the company should do something about an obvious design flaw and then was put on long hold.  I would love to get corporate phone numbers but they seem to be well hidden.. Love how companies have NO ACCOUNTABILITY for their product.    Crazy that I am paying anything for an engineering mistake.  Thought about doing it myself but I am concerned after watching several videos.   VERY DISAPPOINTED... luckily I purchased this drone from a relative and didn't pay the $1700 I was going to for a 4 pro..  I hear the same thing is still happening with them?    AND if the way you fly can cause this, the company should have warnings all over the place explaining how the drone should be flown.  My drone has never been crashed or had any hard landings or anything that would cause this only underneath the motor on one arm and a tiny crack starting on another. It did seem to be flying funny... horizon was not always level and you can actually see the plastic of the arm move when you push on the cracks. It has definetely lost strength.

JJMik Posted at 2018-6-5 07:47
I was cleaning some bugs off my phantom 3 pro and noticed really bad stress cracks under one motor.  Called DJI and no help out of warranty. Asked for supervisor and was put on hold after being told over and over that a supervisor would not help.   I explained the company should do something about an obvious design flaw and then was put on long hold.  I would love to get corporate phone numbers but they seem to be well hidden.. Love how companies have NO ACCOUNTABILITY for their product.    Crazy that I am paying anything for an engineering mistake.  Thought about doing it myself but I am concerned after watching several videos.   VERY DISAPPOINTED... luckily I purchased this drone from a relative and didn't pay the $1700 I was going to for a 4 pro..  I hear the same thing is still happening with them?    AND if the way you fly can cause this, the company should have warnings all over the place explaining how the drone should be flown.  My drone has never been crashed or had any hard landings or anything that would cause this only underneath the motor on one arm and a tiny crack starting on another. It did seem to be flying funny... horizon was not always level and you can actually see the plastic of the arm move when you push on the cracks. It has definetely lost strength.

Replace it yourself. the bottom shell is only $8.00 according to my repair receipt. When you're done back the screw off. DJI over tightens them which is the main problem.  When i got my P3P back I backed the screws off instantly and its been great ever-since.

I thought about doing it myself and watched several videos but in each video there was some doubt about how o disconnect something and I don't feel comfortable..  Im okay with minor mods... HDMI input etc but taking the entire drone apart not so sure.. $40 part on amazon.  nice to here DJI isn't jacking up their part prices too

JJMik Posted at 2018-6-5 09:41
I thought about doing it myself and watched several videos but in each video there was some doubt about how o disconnect something and I don't feel comfortable..  Im okay with minor mods... HDMI input etc but taking the entire drone apart not so sure.. $40 part on amazon.  nice to here DJI isn't jacking up their part prices too

Companies exist to make money! But I agree, it should be a recall fix, its not your fault.

My suggestion would be buy a new shell and replace it yourself.