Hello, my P3S started developing stress cracks (on one arm). I still need the drone for couple of flights (promised to film something) so I can't send it to DJI for repairs. I have few questions regarding my problem:
Can I still fly the drone with this damage? Is it safe?
Maybe I can fix it myself without sending to DJI?
How to prevent further spreading and other arm damage?

All help is appreciated and welcome!!! THANK YOU!

It's not recommended to fly with shell damaged, but you might be able to fly a bit more as long as you're not flying aggressively. Replacing a shell isn't horribly difficult, but the bottom shell can be a bit more cumbersome since you would have to remove the gimbal. Keep in mind that if you damage the gimbal etc when removing it, you would be charged for the repair if there's still warranty on the unit. Some had used epoxy on the cracks, but it could make it difficult to remove the shell when you do decide to replace it.

Many people develop cracks - its a fault of the overall design where the plastic narrows and thins.

Sending to DJI will of course remedy but who says new shell doesn't do same ?

Personally I bought the 3rd party metal arm ends and did repair of my cracks before fitting.

There are many solutions for this. Mine works without too much dismantling.

First I removed the screws in the arm under the motor.
Second - I took a sharp hobby knife and cleaned the cracks producing a slight narrow v along them.
Third - I used PU glue (Gorilla Glue) is a brand name ..... carefully smeared into the cracks.
Fourth - very light water spray to get the PU to react quick and expand.

Once PU has foamed and expanded - I sanded it back smooth and then fitted the metal plates making sure I used the replacement longer screws. (Note if you ever remove the plates - do not use these longer screws).

Why use PU ? Its very light, it foams and expands into cracks etc. Its easily sanded. Its strong. It does not need to open up shell. It does not compromise motor mount.

That has been now flying for months with no signs of more.....
Another remedy is to use Plastic Weld solution applied carefully by paint brush along the cracks .... this is liquid solvent glue used by plastic model builders. Take care as this dissolves plastic to do its job.

Nigel

DJI-Jamie Posted at 2017-5-15 16:35
It's not recommended to fly with shell damaged, but you might be able to fly a bit more as long as you're not flying aggressively. Replacing a shell isn't horribly difficult, but the bottom shell can be a bit more cumbersome since you would have to remove the gimbal. Keep in mind that if you damage the gimbal etc when removing it, you would be charged for the repair if there's still warranty on the unit. Some had used epoxy on the cracks, but it could make it difficult to remove the shell when you do decide to replace it.

I think I would be able to replace the shell myself since I have some practice with similar repairs. But would the DJI send me the replacement shell so I could replace it myself?

solentlife Posted at 2017-5-15 22:36
Many people develop cracks - its a fault of the overall design where the plastic narrows and thins.

Sending to DJI will of course remedy but who says new shell doesn't do same ?

Thanks for sharing your experience. I want to know where you bought the metal arm ends? maybe you can give me an ebay link or something?

fans516b91ad Posted at 2017-5-16 07:45
I think I would be able to replace the shell myself since I have some practice with similar repairs. But would the DJI send me the replacement shell so I could replace it myself?

Unfortunately the Support Center would not be able to provide parts for self repairs like that. Either the unit would come in for a shell replacement or you would have to purchase a replacement shell yourself to do an in home repair.

Phantomhelp.com ....... lists many sources of all parts .. shells, props ... you name it.

As to metal arm ends ... eBay is full of them ... I chose the silver alloy ones.

Nigel

Looks like the one screw was over-tightened which is surprising as they'd have used a tool that would have given the same "torque" to each screw.................. you didn't touch any of the screws did you?  I've had a lot of experience repairing cracks in motorcycle plastic fairing panels and unfortunately, once the crack is there, with any amount of gluing etc, there will still be a weakness there and the cracks will probably reappear............ the only way I've found to stop a crack spreading is to drill a small hole at the end of it.............. not practical here so a new shell is really the  only answer.  

The Best answer to all this is to fit the metal plates BEFORE cracks appear.
Or
To repair and fit plates when first evidence of any crack, now matter how small.

Here we have quite serious cracking and needs careful work to repair. Plus add the plates once done.

My arms cracked months ago and I repaired ... added plates and today no problem at all. I am no gentle flyer - my models work hard for their place in  my hangar !

Nigel

solentlife Posted at 2017-5-17 08:18
The Best answer to all this is to fit the metal plates BEFORE cracks appear.
Or
To repair and fit plates when first evidence of any crack, now matter how small.

I started seeing the motor cracks after about 50 flights on both my P2V+ and P3S.  I have repaired the cracks with both Gorilla glue and JB Weld with no ill-effects.  I've not noticed any unbalancing problems or vibration due to the extra
weight of the JB Weld, and the expansion of the cracks have seemed to stop, though a couple of new ones appear now and then.  I loosened the motor mount screws and retorqued - a couple were very, very tight, which should also be checked as a cause of the problem.  Just keep the glue out of the motor screws.  I've had many flights on the repaired P3S since.

I am very new to drones, but with my many years dealing with mechanical assembles I would say that the screw where the cracks radiate from was much too tight. It might be wise to check the torque of the other screws on all of the arms. In that way you could possibly determine a proper level of tightness.

Hello,
I inspect my P3S after every flight since a repair will be more effective when a crack starts. I have done some internal reinforcements with carbon fiber bracing and applied Plast-Aid from the inside but this required disassembly. There is an option if you don't want to disassemble. It's a glue called Weld-on 4 (the one formulated for acrylics). Just clean with alcohol. After completely dried. Apply a very small amount with a mini brush. This glue will flow into the crack melting the base plastic and filling the crack from the inside just like a weld. According to the manufacturer, a period of 24 to 48 hours will be required for high strength. Just be sure to use a very little amount. It will melt, deform and erode the base plastic if you apply too much. I have stopped a few cracks with this stuff. Hope this helps.

"Weld-on 4" is a form of MEK and is a plastic solvent ...

Nigel

solentlife Posted at 2017-5-18 09:15
"Weld-on 4" is a form of MEK and is a plastic solvent ...

Nigel

You can get a new body from banggood.com for $32 dollars.   Takes a couple weeks to get but I have had good luck with them.

NM_Quad Posted at 2017-5-17 09:22
I started seeing the motor cracks after about 50 flights on both my P2V+ and P3S.  I have repaired the cracks with both Gorilla glue and JB Weld with no ill-effects.  I've not noticed any unbalancing problems or vibration due to the extra
weight of the JB Weld, and the expansion of the cracks have seemed to stop, though a couple of new ones appear now and then.  I loosened the motor mount screws and retorqued - a couple were very, very tight, which should also be checked as a cause of the problem.  Just keep the glue out of the motor screws.  I've had many flights on the repaired P3S since.

Would something like plastic epoxy work to fix the cracks? Since I am not able to get this kind of glue in my country. Also have you used any threadlocker to fix the screws in place after re tightening?

solentlife Posted at 2017-5-17 08:18
The Best answer to all this is to fit the metal plates BEFORE cracks appear.
Or
To repair and fit plates when first evidence of any crack, now matter how small.

Thanks for the information. I'm not a really gentle flyer myself. I want to fix them myself because if I'll send it to DJI most likely I won't get it until the end of summer (which would suck a lot). I ordered metal support plates. Hope they'll help. Also when you re tightened screws did you use any threadlocker? Because I don't want to use loctite 243 since it damages plastic.