Phantom 3 Crack Repairs

[FredSheldon]

It is a weak design. Torque probably caused the issue from the factory on those who had cracks on delivery. Others may see that they developed over time, like mine. It would probably be wise to retorque them to be safe and use the zip ties to reinforce the area. After making repairs on mine, it's very solid. The arms have very little to no torque on them now. I had lots of torque from the factory and I think movement over time caused my issues. I only hand catch. I see it's happening on the rear arms. If torque from the factory is the issue, then why not all the arms? Aren't most of you seeing the rear arms cracking?

I went ahead and zip tied mine with opaque white zip ties I have out in the shop. I figured why not, more support the better. I think after my fix, it stronger than factory now and will probably last me the life of the drone. When shells become available, I'll put one back for just in case.

So I made the choice on mine. I repaired it. But I won't forget when it comes to buy future products. I thought I wouldn't be an early adopter. And you would think on a third generation, these issues would be moot, but here we are.

Buck, the only purpose of the two screws as I see it is to hold the two shell haves together. The Zip ties perform that same function. You therefore could probably remove the screws completely and it will perform as good as new for the life of the copter. Yes, it looks bad, yes, DJI should fix it, but unless you just don't like the looks of the ties, just put them on and move on. In fact, if you ever have a crash, the ties will probably reduce any damage you might have incurred otherwise.

 

[Oso]

My take has been that untightening the screws and then tightening them again will not prevent cracking even if you don't over torque them. IMHO, the best way to prevent cracking is to add ties, and completely remove those two screws. If the screws are in place at all, the cracks will eventually happen due to the thin plastic at that location. Internal glue will delay the inevitable, but not prevent it. If the ties are tight and don't slide, there should be no performance impact.

Disclaimer - I am an engineer but this is not my area of expertise. I am only making an educated guess like most of you guys. Please use your own judgement. I could be totally wrong!

 

[Chuck Young]

My take has been that untightening the screws and then tightening them again will not prevent cracking even if you don't over torque them. IMHO, the best way to prevent cracking is to add ties, and completely remove those two screws. If the screws are in place at all, the cracks will eventually happen due to the thin plastic at that location. Internal glue will delay the inevitable, but not prevent it. If the ties are tight and don't slide, there should be no performance impact.

Disclaimer - I am an engineer but this is not my area of expertise. I am only making an educated guess like most of you guys. Please use your own judgement. I could be totally wrong!

I think I will incorporate a modified version of this tomorrow. I used some PVC tape (looks just like carbon fiber) and a zip tie around each of the arms. I had re-torqued the screws but now think I will loosen the screws to simply snug and put torque seal on them.

 

[ScottyT]

My take has been that untightening the screws and then tightening them again will not prevent cracking even if you don't over torque them. IMHO, the best way to prevent cracking is to add ties, and completely remove those two screws. If the screws are in place at all, the cracks will eventually happen due to the thin plastic at that location. Internal glue will delay the inevitable, but not prevent it. If the ties are tight and don't slide, there should be no performance impact.

Disclaimer - I am an engineer but this is not my area of expertise. I am only making an educated guess like most of you guys. Please use your own judgement. I could be totally wrong!

I don't believe those screws should be removed. A cable tie seems to take the load off the 2 screws.
And I prefer they were there, incase the cable tie came off for any reason

 

[ScottyT]

Just had a quick look at the Solo forum - this issue is being misreported already

http://www.3drpilots.com/threads/screws-loose.454/

"...The P3 is having vibration issues with the props and some folks are getting cracks in the airframe."

"Cracks? Wow.. Vibration issues are NOT good either."

 

[johnp44]

I know of no other craft that users take out magnifying glasses to examine them."

When you have the problem, you don't need a magnifying glass to see the cracks. They start out as small cracks and just keep getting longer and wider.
You either fix em or just ignore them until a major problem occurs. If you search shell cracks you will see the that the problem is real and not happening to just a few who use a magnifying glass.

 

[jasonb777]

To the guys using bondic, I'm curious to know if you were able to get a good seal around the circumference of the shell along the seam? It seems like it would be hard for the light to penetrate and get a good seal once you mashed your shell back together. Looking for a fix other than zip ties, so if that worked good for you guys please let me know..

 

[ScottyT]

To the guys using bondic, I'm curious to know if you were able to get a good seal around the circumference of the shell along the seam? It seems like it would be hard for the light to penetrate and get a good seal once you mashed your shell back together. Looking for a fix other than zip ties, so if that worked good for you guys please let me know..

The examples I have seen are just strengthening the internal surfaces, not actually gluing the shell halves together.

 

[icekepal]

Hi everyone, from my opinion is this cracks maybe also cause by long term vibration of the motor due to unbalance motor hub and the stock blades..

Can anyone check about this matter, you will need Du-bro balancer..

 

[ScottyT]

Hi everyone, from my opinion is this cracks maybe also cause by long term vibration of the motor due to unbalance motor hub and the stock blades..

Can anyone check about this matter, you will need Du-bro balancer..

Possibly. I was thinking of getting a balancer - what is the thread size for the P3 props?

 

[jasonb777]

I had read on an older thread concerning cracks that a few people had glued the shells together which will strengthen the whole bird. One solid bird that doesn't flex or shimmy at the seams is more durable than reinforcing the bottom of the plastic posts. As I said earlier, the cracks are more than the base, sometimes the top of the base not the bottom, and in my case whole chunks broke off...

 

[ScottyT]

I had read on an older thread concerning cracks that a few people had glued the shells together which will strengthen the whole bird. One solid bird that doesn't flex or shimmy at the seams is more durable than reinforcing the bottom of the plastic posts. As I said earlier, the cracks are more than the base, sometimes the top of the base not the bottom, and in my case whole chunks broke off...

'Struth. On the P3? Got pictures of that?

 

[jasonb777]

As I said, there is a chunk missing from the post scotty. And you say you fly your bird pretty rough, well I just back from flying all over the smoky mountains here in N.C. and the wind gusts on top of those mountains are raging. When I got back to the beach here in swansboro where I live I noticed the damage that was done. What you see is the two back arms in the pics.

 

[ScottyT]

As I said, there is a chunk missing from the post scotty. And you say you fly your bird pretty rough, well I just back from flying all over the smoky mountains here in N.C. and the wind gusts on top of those mountains are raging. When I got back to the beach here in swansboro where I live I noticed the damage that was done. What you see is the two back arms in the pics.View attachment 24792 View attachment 24793

Sure, that's what everyone is trying to repair - probably before it gets to that point.
That's still 'just' the bottom shell. You could seal the craft but then you'll not be able to get in to it again for any other repairs or replace the shell when they are available to buy. Each to their own.

Sending it in for repair is not an option for you now it has cracked that badly?

 

[Sandstorm76]

My P3 arrived yesterday. Flown it a few times for 10 minute flights. Looking at my rear arms one of the screw holes looks like the plastic is slightly different as if there was a defect in the mold. Similar shape to the photo above but not quite got a crack that I can see. I think I will cable tie all 4 arms to be safe.

 

[Sandstorm76]

My P3 arrived yesterday. Flown it a few times for 10 minute flights. Looking at my rear arms one of the screw holes looks like the plastic is slightly different as if there was a defect in the mold. Similar shape to the photo above but not quite got a crack that I can see. I think I will cable tie all 4 arms to be safe.

 

[BuckRogers]

As I said, there is a chunk missing from the post scotty. And you say you fly your bird pretty rough, well I just back from flying all over the smoky mountains here in N.C. and the wind gusts on top of those mountains are raging. When I got back to the beach here in swansboro where I live I noticed the damage that was done. What you see is the two back arms in the pics.View attachment 24792 View attachment 24793

Those are good pictures. Shows you how thin at the curve the shell is. It's no wonder it cracks there.

to the question about using bondic on the seems. I wouldn't do it. Any sort of movement in the shell could cause the seem to crack along the bondic. Then you have a bigger problem. And you are done. You will have to cut into it to get inside for a new shell. or anything else. I would think that warranty wouldn't even accept it.
To those that have cracks starting, if you don't want to open your shells, then the zip ties are the best bet.

 

[Kman]

My P3 arrived yesterday. Flown it a few times for 10 minute flights. Looking at my rear arms one of the screw holes looks like the plastic is slightly different as if there was a defect in the mold. Similar shape to the photo above but not quite got a crack that I can see. I think I will cable tie all 4 arms to be safe.

Same with the new one DJI sent me. I'm ruing zip-ties just to be sure.

 

[Sandstorm76]

I'm the guy you're talking about. My new unit doesn't have stress cracks like I stated in the video, but the right rear arm, inside screw hole has some mold marks in the EXACT location my first unit cracked at. It's hard to see in the video. I wish you guys could all see my P3 in person.

I loosened the shell mounting screws and re-torqued them to hand tight on my new unit. I also added zip-ties to each arm. They need to be as tight as possible. The shell pieces by themselves are weak and twist. When they are screwed together they are extremely strong. What happens is the cracking occurs and the shells become weak because they aren't tight together. The zip-ties adds support to keep the two pieces together.

Clearly DJI knows there is an issue. If not why would they send me a brand new unit and then have me send my cracked unit in?

Exactly the same as me mate, as shown in my picture. Will get the zip ties on today to be safe.

 

[isopro]

Im at 124 flights, 200Km flown, and after inspection i detected cracks on all sides, the back arms have cracks on 1 screw per arm, and the front arms have cracks on 2 motor screw mounts per arm,,,Contacted DJI and they said i've to send back the unit with a minimum turn-arround time of 8 week after it is checked in !!!!
So basicly i would have to not fly again for rest of summer, this is a BAD solution, i never touched the shell, 0 hard landing, 0 crash, I still use the same blades since day 1, they do have lot of bug kill marks but no cracks or anything....I never expected cracks to form there so it was not part of my check routine, only after reading about this I checked and found that so maybe they have been forming for a while...Here are photos of my P3A i sent to DJI with zoom on the photos with the cracks...Should i keep flying like this ? !!!! This is scary...And what they offering is unacceptable, 8 weeks turn arround is NOT how RMA for defect is suposed to work, they should send me a new complete BODY with no mistake and a box with shipping label to ship back my old body...

The scaryest pic is 9/21....look that crack OMG !
https://www.dropbox.com/sh/xv3nyg26ndw21y7/AAA_wjuk8Lg9LJtBWNUrqlkPa?dl=0