I got an idea to fix the inevitable cracking of plastic airframe. I used to have a phantom 3 pro which also developed hairline cracks over time. Dji has to integrate line x coating to make airframes strong.
I also had a design idea that could make the inspire 3 portable but Dji did not bother replying, I think they don't care about other ideas for innovation if the it doesn't come from them.. anyway

Get Line x to spray poly coating. Google for the nearest line x location.

Before you go there

Disassemble phantom 4 or 3, take off all internals first.

tape up the screw holes, interior gps area, outside and edges where you don't want the black colour on and any part that you don't need coating. Only The arm's interior has to be coated lightly and evenly so that it does not get too thick.

It's better if you do this on a new or undamaged shell for full reinforcement.

It will make the airframe stronger and crack free. For big crashes your phantom 4 or 3's arms will be resistant.

Thanks guys, this is the only long term solution I can think of for plastic frames.

You need Jesus

When I have Jesus - do I still need that coating?

Jesus cut my lawn.
Jose does the edging and blowing.

Eric13 Posted at 2018-3-3 03:33
When I have Jesus - do I still need that coating?

You don’t know Jesus

I got an idea to fix the inevitable cracking of plastic airframe.
Inevitable??
Since only a very small number of Phantoms ever develop cracking, for most users this would be a waste of time and effort.
It will make the airframe stronger and crack free.
Heavier too.
And since the Phantom was unlikely to ever crack anyway, it's most likely a wasted effort.
this is the only long term solution I can think of
Doing nothing is a better solution for most users.
In the unlikely situation that cracking develops, get DJI to replace the shell under warranty.

Labroides Posted at 2018-3-3 21:59
I got an idea to fix the inevitable cracking of plastic airframe.
Inevitable??
Since only a very small number of Phantoms ever develop cracking, for most users this would be a waste of time and effort.

All phantoms due to plastic airframe will get a crack eventually so it is inevitable. If you fly not fast and in little wind conditions then it will only take longer for it to happen.

Warranty does not matter since cracks tend to appear after a year.

Also it is the lightest solution, a light and even spray only.

I do not believe only a small number develop cracks ... its evident on old and new design shells ... just have to look at posts about it.

Recent Poll came out too close in numbers to be certain - but had a significant number of Yes - cracked.

End plates don't stop cracks - but can help stop them spreading or starting.

Adding resins ? The Engineering plastic used is actually not that good as a bonding surface ... you could add epoxy for example and later crack it away as a 'mould' literally. PolyUrethane glue - that expands with moisture is a better resin to use as it is very light and actually 'bonds' reasonably well. But it needs to be applied inside and also controlled in its expansion to not affect motor mount / shell fitting.

There are umpteen versions / claims of remedies .... personally I don't think any one of them is any g'tee.
When you dismantle the shell - you start to understand how flexible it is without being screwed together .. it derives its strength not from bulk - but locking the two shells together. Unfortunately at end of arms - you have thrust and motor weight all meaning varying stress on possibly one of the weakest areas of the body.  

As to DJI replacing shell ... fine if within warranty period - and then as posted by various - they only got ONE replacement - when that cracked ... no deal !!

Nigel

Al S. Alice's Handler Posted at 2018-3-3 04:45
Jesus cut my lawn.
Jose does the edging and blowing.

Made my day!!!

As I said in another thread, just buy a bottle of extended warranty

The poly spray line x makes watermelon surface crushproof lol

I also agree that just about all of them show some cracking. Some more than others. I have repaired a number of these and I do apply a small amount of 2-part epoxy inside the shell when replacing it now. I make it standard practice now and won't replace a shell without doing this first. I use a small paint brush and go around the mounting holes and bosses where the motors attach. I can say it makes a huge difference. I go one step farther and use the 3-d motor reinforcements, but also put a little epoxy on them. They are cheap, and if I ever have to replace the shell, I'll sacrifice these and buy a new set. It does make these arms more rigid for sure, and I have several that I have done with no cracks showing at all. I think those that think this is an isolated problem are incorrect. And most of us have phantoms that are way out of warranty, and I for one am not going to pay DJI to replace a shell knowing I'll have the same in a few months. I tried this on my own. Replaced several shells with new ones, and the cracks came right back. I was determined to try something to help. I think this guys idea of spraying the shell is not way out of line, but maybe a bit more than most of us can do. For me, the main issue for all of these is pretty much just around the motor mounting bolt holes where all of the twisting and torque is going on.

QuadKid Posted at 2018-3-4 03:05
As I said in another thread, just buy a bottle of extended warranty
[view_image]

Polyurethane Glue in local DIY shop is same stuff and far cheaper !!



The yellow bottle is ~3x volume and 1/2 price of GG ..... and its the Water-Proof variety ....

Nigel

solentlife Posted at 2018-3-4 07:41
Polyurethane Glue in local DIY shop is same stuff and far cheaper !!

[view_image]

Ok so those are the alternatives?

I think alot of those "inevitable cracks" can be avoided by doing some preventitive maintinence. Like checking the mounting screws. I'd say after ever few hours of flight time. Its not like its going to take hours to do. After all.... You check your cars dipstick from time to time don't you? You check your tires, radiator... you even fill it full of gas. Just because the Phantom doesnt have an idiot light doesnt mean you should ignore these things in the first place.  My 2¢

IamWedge Posted at 2018-3-4 16:03
I think alot of those "inevitable cracks" can be avoided by doing some preventitive maintinence. Like checking the mounting screws. I'd say after ever few hours of flight time. Its not like its going to take hours to do. After all.... You check your cars dipstick from time to time don't you? You check your tires, radiator... you even fill it full of gas. Just because the Phantom doesnt have an idiot light doesnt mean you should ignore these things in the first place.  My 2¢

Duck tape fixes all

djiuser_fiQgdFqHaUQg Posted at 2018-3-4 01:31
All phantoms due to plastic airframe will get a crack eventually so it is inevitable. If you fly not fast and in little wind conditions then it will only take longer for it to happen.

Warranty does not matter since cracks tend to appear after a year.

I've only had 6 and I fly them hard - none have shown cracks.
None of my flying friends have any.
My count of forum posts also suggests it's only a very small percentage.

But you just can't tell some people.
If they all cracked up, the forum would be 90% about the issue.

Sorry L ... but I think there are more posts about than just a few. It has constituted some of the longest running threads in fact ... not only here but also on other forums.

Its also a personal observation ...

My P3S cracked soon after I got it ...
Other club members I fly with (P3S, P3A and P3P's ... 10 in all) - at least half suffered cracks.My P3P has no cracks but shell was repaired after hitting the tree not too long back ... so I cannot count that yet. I think about fitting my plates - but so far not bothered.

The fact is though - it does not matter if its 1 or 1 million get cracks - the fact is it can happen.

Iamwedge : As to frequent checks of motor mount screws ... what indication are you looking for ? For example my P3S ... I was checking often - and all screws were properly tightened, no loosening etc. But it cracked. Its not like checking tyres or oil of the car ... they give definite signs of change. Only sign you have with this - is the actual cracks !!

Nigel

solentlife Posted at 2018-3-5 06:18
Sorry L ... but I think there are more posts about than just a few. It has constituted some of the longest running threads in fact ... not only here but also on other forums.

Its also a personal observation ...

Same with my p3 pro and a lot of p4's are reported to have this. I think the cracks came right at 20 hr flight time. But I flew fast like half the time.

solentlife Posted at 2018-3-5 06:18
Sorry L ... but I think there are more posts about than just a few. It has constituted some of the longest running threads in fact ... not only here but also on other forums.

Its also a personal observation ...

True, no signs until the actual cracks appear.  

The checking of the screws could be part of the problem, when folks check, they may over tighten them thus invoking the rite of the "cracking"