Just received Aluminum reinforcement plates. Very good quilty, and considering it came from China, very fast shipping.
Last summer I had my P3P repaired by DJI (sorry, exchanged) for stress cracks. I flew maybe three hours since and the cracks are back.
DJI refused to repair the drone again claiming, it is past the warranty. This problem is not going away, so I decided to install the plates before the cracks get any worse.
Here is the link to the eBay source:

http://www.ebay.com/itm/4x-CNC-Metal-Reinforcement-Plate-For-DJI-Phantom-3-2-Motor-Mount-Base-Protective/371831083021?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Did the cracks come back in the same places?

Yes, but so far, on just one motor mount.

I experienced the same thing, but fixed mine myself. After the second shell replacement to avoid further cracking, I started using the reinforcements too. I do a little repair on phantoms for friends locally, and I won't replace a shell without putting them on. So far, it has totally been the right thing to do. I have not had 1-phantom show any cracks since using them. I think you will be happy with them.....no matter who you buy them from. Enjoy.

Thanks for reassuring word. I was not sure how well that would work.

Try this one:

http://www.ebay.com/itm/4x-CNC-M ... dc100d:g:CZkAAOSwZQ

So sorry for all inconvenience. Free of charge might be applied when the drone is in the warranty period. You are welcome to send it in, but additional charge might be needed, please kindly understand.

Dear Susan,

Have you ever heard of a "manufacturer's recall"?  A manufacturer's recall is when a company discovers that some component is prone to fail, it will cover the repair way past the warranty period.

In this case, we all know that this is a very common issue due to a defective plastic process. Also, this problem can cause injury or damage to people or property if the motor brakes off.

The least DJI can do to correct this is to send the reinforcement plates free of charge.

Wow same thing here... 1st cracked shell fixed myself.
And now cracks on same arm

Let me guess we all the front left arm...
Hmmm

Mine cracked right after I started flying it over two years ago (P3A).  I have run the prop guard snap-on plates without the guards ever since.  Just like the Energizer bunny, it keeps on keeping' on..

AG0N-Gary Posted at 2017-10-7 17:49
Mine cracked right after I started flying it over two years ago (P3A).  I have run the prop guard snap-on plates without the guards ever since.  Just like the Energizer bunny, it keeps on keeping' on..

yea agon-gary iput those on my p3p when new but ive never looked under them since they were installed.i hope they hold down the cracks.ha ha.

The plates do not stop cracks happening - but it slows their onset.

The important part is to make sure the inner two thinner screws are fitted with the short tubes. These two lock the shells together and stiffen the arm end by securing the plates. The plates then of course spread the motor mount loads.

For real peace of mind - the total solution would be bonded plates running along the arms out to motor areas ... but that's a serious job to do. I haven't seen any offerings in that yet.

Nigel

I pulled my plates not too long ago to take a peek.  There are what looked like a few more cracks, but they can't go far.  If I have occasion to pull the shell apart again (did it long ago), I'm going to fill those cavities that are in the lower part of the bottom shell where the motor and shell screws are with hot glue.  Those are the areas that are cracked.  I'm not about to replace the shell with yet another plastic shell that will crack again.

AG0N-Gary Posted at 2017-10-8 18:25
I pulled my plates not too long ago to take a peek.  There are what looked like a few more cracks, but they can't go far.  If I have occasion to pull the shell apart again (did it long ago), I'm going to fill those cavities that are in the lower part of the bottom shell where the motor and shell screws are with hot glue.  Those are the areas that are cracked.  I'm not about to replace the shell with yet another plastic shell that will crack again.

You might be better getting such as MEK (Plastiweld) .... and painting the cracks with it. Its a plastic solvent used by plastic model makers to melt and weld joints.

Nigel

solentlife Posted at 2017-10-8 23:38
You might be better getting such as MEK (Plastiweld) .... and painting the cracks with it. Its a plastic solvent used by plastic model makers to melt and weld joints.

Nigel

May be a silly newby question, but if there are so many problems with cracks, why does everyone not use
plates so  ?

daphil Posted at 2017-10-9 03:42
May be a silly newby question, but if there are so many problems with cracks, why does everyone not use
plates so  ?

Because they are not DJI issue.

DJI in fact - if you look back through various threads actually try to discourage their use.

As I said earlier - they are not a CURE .... they are a band-aid for the problem and only SLOW the cracking process down.
If not fitted right - they could in fact make situation worse and is why I posted about making sure all 6 screws are used ... not just 4 motor ones as I have seen.

Nigel

When I noticed stress cracks I dabbed a very small amount of super glue over the cracks....never got any worst and haven't seen any new cracks. I agree that DJI has many faults... with their software, material and customer service. They also seem to fail to test their new software upgrades before making them available to the public.
As long as people keep buying from DJI they will continue their bad service and poor quality.....just saying.

I reinforced the inside my new shell with epoxy on all screw mounts and moter mounts kind of painted on then used the plates and I have no cracks with over 20 flights

I reinforced the inside my new shell with epoxy on all screw mounts and moter mounts kind of painted on then used the plates and I have no cracks with over 20 flights

Plast-aid is a good product to build up the area on the inside of the wing under the motor which would strengthen that area and hopefully prevent cracks, if that's something one is worried about.  The plast-aid is white and actually hardens harder than the stock plastic.  

I fly a P3A for an agency.   I have a P4A of my own.

After 8 mo of flying and approx.  12 hrs, STRESS CRACKS on two opposite motor arms, underneath, on the screw sockets.

I epoxied them, test flights, and decided to have the hull replaced due to being used by an agency.   

DJI will not agree to the plates as they are not part of the factory w&b.   Liabilities.

That said, something should be done with the hard plastic shell and to provide assistance to the owners who have had issues.  As more companies begin designing and building quality drones, any company that doesn’t provide customer service, top knotch, will suffer.

My P4A battery cases have cracks from molding/injection points.   Nothing done.   Told to buy new batteries.   HA!

Noticed those on my own drone; now the charger has died; wanted to post a thread asking about that, but can't, don't have enough "points".

Had thought that the software quality was low, but hardware alright - clearly not, then, if the shell cracks apart under normal use and the motors can detach... :-O