DJI's comment on cracking around motors

[nickyb]

Am about to buy a P3P here in the UK, but was concerned by the threads on these cracks/micro cracks around the motor areas.

So I contacted DJI support Europe (Germany) and they commented below:-

Support4.Europe (DJI)

Sep 14, 17:17

Hello sir,

One batch of drones reveal this problem and the warranty of course covers if. If you drone shows such a problem it will be recovered.

Best regards
Technical support
DJI GmbH


..

They do not say much, but looks like a batch issue. I also contacted a leading DJI distributor in the UK, HeliGuy, and they also confirmed that new P3A/Ps coming into stock with strengthened holes, email portion below from them:

The new units we keep in stock are now coming through with strengthened plastic around the screw holes,

Hope this information helps

 

[pbrain]

I would be interested to know which 'batch' is affected, and how you identify which batch the P3 comes from.

 

[nickyb]

I would be interested to know which 'batch' is affected, and how you identify which batch the P3 comes from.

I did ask DJI Germany and they commented on email ..

Hello Sir,

We do not know the exact batch date. If a problem occur we will either give you another drone or will replace the shell.

Best regards
Technical support
DJI GmbH

 

[pbrain]

I did ask DJI Germany and they commented on email ..

Hello Sir,

We do not know the exact batch date. If a problem occur we will either give you another drone or will replace the shell.

Best regards
Technical support
DJI GmbH

Interesting - I'm sure they must know which batch(es) have been affected, purely based on which P3's they have repaired/replaced under warranty for this issue. That's a very vague answer!

 

[Mako79]

I think it's an epedemic and dji will not admit fault. They will roll with it and revise the shell.

It's that cliche... not a question of if but when...

 

[nickyb]

Interesting - I'm sure they must know which batch(es) have been affected, purely based on which P3's they have repaired/replaced under warranty for this issue. That's a very vague answer!

Yes very vague, obviously they do not want to admit liability and cause a flood of owners wanting (quiet rightly) a replacement shell etc. However they do semi admit a problem since they said they would replace the drone/repair, as on the DJI site the shell/airframe is clearly not under warranty.

Once I get mine I will investigate on any changes and post.

 

[brianb87]

They should release the batch number and replace them, free of charge.

 

[nickyb]

Just an idea, thinking of all the users with this issue, maybe email DJI technical support 'en mass', as they have semi admitted liability (as did a DJI tier 1 distributor of a modification change) and demand free replacements, surely its worth a try!

 

[nickyb]

I have recieved this new reinforced version it has an X shaped portion between screw holes and every screw hole has additional 4 strengthening patterns. The shell anyway cracked in less that 50 flights. Now new shell that i bought because no response from DJI is 2 times weaker

Am gutted! So this new design also cracks then?

 

[Daninho]

they dont tell it because a "batch" is the wrong word for it. The truth is that all P3s are like that, they changed the shell quite recently and that means the "old ones" are a massive amount of P3s. If you bought your P3s just recently you could be lucky

 

[MattyDread]

Buy the P3A - unless you have a top end pc/laptop, 4k tv etc.

You can buy a P3P charger & extra battery for the same price & still get great 2.3k video

 

[nickyb]

I'm thinking of writing back to DJI Support saying that many users of the P3 are having to pay for either replacement shells or buying that retro fitted bit of plastic to strengthen the arms

You can see "new shell" ( i got one of the freshest Phantoms from production so i guess it is new) on the bottom that laster 40-ty something flights. Disregard the glue, it was just a fix until new shell arrived. At top you will see new shell and see howmuch weaker is it. The DJI dealer said this are the newest shells just recieved, maybe they are getting rid of old shells trough spare parts.

Looks like a half arsed (and cheap) tooling fix from china. Maybe also sitting the motors on some shock absorbing materials would also help reduce the fatigue.

 

[Mako79]

You can see "new shell" ( i got one of the freshest Phantoms from production so i guess it is new) on the bottom that laster 40-ty something flights. Disregard the glue, it was just a fix until new shell arrived. At top you will see new shell and see howmuch weaker is it. The DJI dealer said this are the newest shells just recieved, maybe they are getting rid of old shells trough spare parts.

Um ok... What model is yours??
I'm confused... My P3A was one of the "first batches". It was bought in Aus, May 2015. I'm very sure it was the first batch. Now looking at the pic, I have the top version WITHOUT the reinforced X.

I did the same mod as you as a preventative measure except I used a glue gun.
Could it be that your supplier is just dumping old stock and calling it new??
Could it be that P3P has different shell than the P3A?
Could it be that "all" shells crack, revised or not??

 

[nickyb]

I have now emailed DJI Europe support again, asking for a resolution for phantom owners with the cracking shell problem, both new and old style airframes...

Hello,

Thanks for the reply below. I am a member of phantompilots.com forum.

This cracking problem with the airframe, near the motors seems to be a big problem with owners, some have
resorted to either buying a new airframe, and/or buying retro fit parts for the motor area to help prevent cracking.

One would assume most of the owners would fly there P3 correctly, no crashes, bumps etc, so I would expect
that owners can contact DJI for either a fix and/or replacement. Is this correct?

I have also been informed that DJI have modified the motor area with extra support, so DJI assumes that
there was an 'issue' with the original design, due probably to increased motor power.

Also, a few users who have the new Phantom 3 (with this modification) have also experienced cracking in
the same place, so it maybe the case this modification does not work.

As you would imagine the P3 is a lot of money for many and for me especially, I have not budgeted (or could
afford) a replacement airframe and be without the P3 for any length of time.

Please can you respond to this email, in such a way so that I can inform others of what course of action DJI
intends to do on this matter, me for one needs convincing before I spend my hard earnt money.

The Phantom series is a brilliant product, but owners need support on this issue.

Await to hear back,

 

[43k]

I think there is room for an aftermarket add-on consisting of this for each motor:

1. a heat shield fitted between the motor and the plastic (just a thin isolating inlay with holes for the screws)
2. an aluminum plate with four holes, placed under the arm, between screw heads and plastic
3. four slightly longer screws, maybe with wider heads

The heat from the motor would be transferred through the screws to the aluminum plate, and less heat would build up in the plastic.

 

[RoyVa]

Normally cracking doesn't come from heat but from stress. Heat helps it to weaken it but stress from torque and twisting is usually the culprit. Don't think a heat sink would help. They really need to modify the plastic mounts and install brass or light aluminum screw threads simular to a Heli-coil or a Full-Torque insert. Those won't crack as plastic does.

 

[III% Streve]

It has already been shown that there is NOT significant heat in the area of the mount. Vibration from unbalanced props, counter-forces from the canted mounting, and the weight for the overall craft, all put a LOT of abnormal stresses in a place that is, from an engineering aspect, not designed for anything but direct vertical stress. The best solution is to spread the load from the 5 screws on and around the motors out to more of the arm. Strong Arms addons, and blade protector mounts COULD help in this, but ONLY if the surface that the replacement screw presses on inserts all the way to the old mounting surface and meats the bottom of the arm with full contact. As if being cradled. I don't believe they do! I don't own any, so I cant say for sure. I have debated working up a set of aluminum or magnesium braces. But as of yet I have not started creating the needed renderings.

 

[fin032]

Mines is in the box ready to get shipped back to Heliguy here in the UK. I bought from them because they are a DJI repair centre and do warrantee work. Meant to be only a few days wait time instead of DJI's 60 day plus.

I will let you know how I get on. I understand that people don't want to wait for DJI so they pay and fix the problem them self's. DJI will love that. If everyone sent there units back DJI would know how big the problem was and need to do something, maybe do better testing in the first place.

 

[43k]

Normally cracking doesn't come from heat but from stress. Heat helps it to weaken it but stress from torque and twisting is usually the culprit. Don't think a heat sink would help. ...

It has already been shown that there is NOT significant heat in the area of the mount.

How was that shown?
Or was it an assumption?
And how much is "significant" in this case?

As I suggest in my post, #18 above, anchoring the screws in a metal plate under the arm will both strengthen the mount by relieving stress from the plastic in the mount, and lower the temp buildup in the plastic.
I can't see how that would not help.

 

[III% Streve]

It was looked at through thermal imaging that even after running through a battery the max tem of the plastic was only 44-45 degrees. Warm, but hardly abnormal or degrading for thermoplastics.