Cracks ... me too

Atlantic Surfer · Nov 18, 2016

Not a big surprise but always a bad news : my P3A is cracking too !!
And of course out of garantie.
To be fair with DJI, it's just after loading it with a 365 g auxiliary battery not well balanced. Cant push the limits and cry when you reach them ...

alokbhargava · Nov 18, 2016

Bad luck. You need to get it fixed ASAP

Sent from my iPhone using PhantomPilots

jnix · Nov 18, 2016

Atlantic Surfer said:
Not a big surprise but always a bad news : my P3A is cracking too !!
And of course out of garantie.
To be fair with DJI, it's just after loading it with a 365 g auxiliary battery not well balanced. Cant push the limits and cry when you reach them ...
View attachment 68942

Make sure you get the 2nd generation shell, it has more structure than the garbage original one does.

They sell it here: DJI Body Shell for Phantom 3 Professional / Advanced

Atlantic Surfer · Nov 18, 2016

Thanks guys
And what about Superglue (cyanoacrylate ) or epoxy ?

jnix · Nov 18, 2016

Atlantic Surfer said:
Thanks guys
And what about Superglue (cyanoacrylate ) or epoxy ?

I used the 2nd gen shell and PLASTIC epoxy on the bottom shell on all 4 arms where the motors attach. I filled them all the way until it was even with the 4 post that the motor sits on. Make sure to fill them as equal as you can for balance but if not perfect its not a huge deal, just try. I have flown mine about 15 times with no problems. It flies straight and worry free. Some people have there methods and glues to use but for me and 2 of my friend that also got cracks this method worked great for us. Mine got cracks on the 3rd flight of my p3p and I was really pissed off. This is something that they need to address, but they wont. All they want to do is sell you the same original shell and have it crack again. The site that I provided you with is the 2nd gen shell and to date I haven't had any problems with the way I modified my bird (for the better) Make sure when you tighten the screws up to only tighten light not over do it like they did from the factory.

RC Madman · Nov 18, 2016

I am curious if people that are posting these cracks are doing "maintenance" tightening of the motor mount screws?

Atlantic Surfer · Nov 18, 2016

Thanks jinx
Any pictures ? And what difference you do between Plastic epoxy and epoxy ?

Numone · Nov 18, 2016

Atlantic Surfer said:
Thanks guys
And what about Superglue (cyanoacrylate ) or epoxy ?

I don't think either will adhere to the plastic very well, if at all. Cyano isn't designed to be used under stress. Any twisting will make the joint fracture again.

jnix · Nov 18, 2016

Atlantic Surfer said:
Thanks jinx
Any pictures ? And what difference you do between Plastic epoxy and epoxy ?

No pictures and the epoxy I used was LOCTITE epoxy and it say for plastic on the package.

GMack · Nov 18, 2016

Do those screws that hold the motor on have any thread-lock on them? I know from my motorcycles that thread-lock is not advised on plastic windshields as it causes them to get brittle and crack for some reason. I've seen little spider web cracks form around those holes in the past and one aftermarket shield maker said not to use the stuff near plastic shields. He said there are some screws that have the stuff applied, allowed to dry, and do not out gas and cause the issue as with the wet thread-lock on the screws.

jnix · Nov 18, 2016

Numone said:
I don't think either will adhere to the plastic very well, if at all. Cyano isn't designed to be used under stress. Any twisting will make the joint fracture again.

Haven't had problems and its better than most methods ive seen on this forum or anywhere. I agree under stress (flex) it might not work if you only put a small amount that's why I filled it all the way to the motor post so the glue will be attached to a lot of the structure (plastic) in the arm.

Robert Whitaker · Nov 18, 2016

jnix said:
I used the 2nd gen shell and PLASTIC epoxy on the bottom shell on all 4 arms where the motors attach. I filled them all the way until it was even with the 4 post that the motor sits on. Make sure to fill them as equal as you can for balance but if not perfect its not a huge deal, just try. I have flown mine about 15 times with no problems. It flies straight and worry free. Some people have there methods and glues to use but for me and 2 of my friend that also got cracks this method worked great for us. Mine got cracks on the 3rd flight of my p3p and I was really pissed off. This is something that they need to address, but they wont. All they want to do is sell you the same original shell and have it crack again. The site that I provided you with is the 2nd gen shell and to date I haven't had any problems with the way I modified my bird (for the better) Make sure when you tighten the screws up to only tighten light not over do it like they did from the factory.

Is there a way to know if you have a 2nd generation shell? I had cracks and my unit was replaced under warranty.

jnix · Nov 18, 2016

GMack said:
Do those screws that hold the motor on have any thread-lock on them? I know from my motorcycles that thread-lock is not advised on plastic windshields as it causes them to get brittle and crack for some reason. I've seen little spider web cracks form around those holes in the past and one aftermarket shield maker said not to use the stuff near plastic shields. He said there are some screws that have the stuff applied, allowed to dry, and do not out gas and cause the issue as with the wet thread-lock on the screws.

On the new shell I bought comes with new screws that have the blue lock tight on them. I di not use them for the same reason you just said. I used the original ones that came with the bird with only about 30% of the lock tight still left on the screws. After abought 7-10 flights just check the screws to see if the loosen up a little. I haven't had any problems.....

Atlantic Surfer · Nov 18, 2016

RC Madman said:
I am curious if people that are posting these cracks are doing "maintenance" tightening of the motor mount screws?

Not sure if your question is for me and if I understand it. Do you mean , releasing some stress off the body shell, unscrewing a little the mounts ?
If yes, the answer for me is No ! When all is working well, you (i) don't want to touch anything. I presume, there is some thread locker on each screw. So you have to unscrew 16 screws, clean the screws, re thread lock them, and put them back. With no information about which torque to apply ...
Now, as the crack is here, I'll do that to fix them

jnix · Nov 18, 2016

Robert Whitaker said:
Is there a way to know if you have a 2nd generation shell? I had cracks and my unit was replaced under warranty.

Under the motors you will have what they call strut support under the motor in that little box. In the original shell it is just a plain square frame (under the motor) and the gen 2 has a x built up in it to try to help for support. There are other things as well but this is a upgrade for the stress cracks for the motor support.

Atlantic Surfer · Nov 18, 2016

I have seen a tip here to see if you have the new shell, put your motor mount in front a very bright lamp and by transparency you should see the cross

jnix · Nov 18, 2016

Atlantic Surfer said:
Not sure if your question is for me and if I understand it. Do you mean , releasing some stress off the body shell, unscrewing a little the mounts ?
If yes, the answer for me is No ! When all is working well, you (i) don't want to touch anything. I presume, there is some thread locker on each screw. So you have to unscrew 16 screws, clean the screws, re thread lock them, and put them back. With no information about which torque to apply ...
Now, as the crack is here, I'll do that to fix them

I'm not telling anyone to loosen 16 screws on their bird. I'm only saying if you are replacing your shell due to stress cracks to not go crazy and tighten up the screws like they did from the factory, which is the main reason for people having stress cracks. If you do replace your shell use the 2nd gen frame with a little better support, that's all I'm saying.

jnix · Nov 18, 2016

Atlantic Surfer said:
I have seen a tip here to see if you have the new shell, put your motor mount in front a very bright lamp and by transparency you should see the cross

That makes sense.....GOOD ONE!!!

Steve7777 · Nov 18, 2016

When my new P3P arrived in April the first thing I did (owing to having been reading here) was to slacken off the motor-mount screws very slightly, fit some prop guard mountings (although I don't ever use them) AND put a few winds of 5mm (cut to width myself) duct-tape around the extremities of the four arms.

So far, after quite a few flights, no problems at all (touch wood)...