Screw inspection = very bad day

[NoOne]

Others are so perfect in shape that they become far harder to notice. But they are there.

View attachment 23196

This pic is exactly representative of my hairline cracks in the screw holes that are starting to form. Although mine have not opened up yet, this is what I'm sure they will become in a few more flights.

I may have to try your super glue method to prevent them from getting worse. I wonder if there is a particular kind of epoxy that would be most appropriate for this plastic. Would a Loctite epoxy be stronger than the crazy glue? How did you use a zip tie to hold the arm together since the glue dries so fast?

I'm thinking this should do it - http://www.loctiteproducts.com/p/13/6/epxy_qset_s/overview/Loctite-Epoxy-Quick-Set.htm

It's absolutely ridiculous that I'm even pondering this on something that I have carefully used a little over a month!

 

[bighi]

No solvents. I sometimes use a fingernail to scrape dead bugs off the shell. Or a paper towel. Dry. But I can't speak for whatever chemistry resides within the organism of a fly or moskito. But those are almost 100 percent of the time on the top shell. Most bugs get killed by the propellers.

Assembly or whatever, had I sent in the P2V+ I received in January that developed cracks on the motor screw holes after three weeks, I would factor a week to ship it back. Figure a week minimum at the DJI Germany center, another week to get it back to either my home in Austria or Italy. And that's at best case scenario, two and a half to three weeks no phantom. Then my number two, new in box P2V+. Noticed cracks, motor mount screw to seam line, after a couple of days. Again, 2 and a half to three or maybe four weeks. Number 1 P2V+ I parked in the shelf cause P3 came out and I ordered. But I ordered two in case cracks showed up. We're talking a lot of weeks here so I decided to glue this P3. My number 2 P3 is still sealed in the box. I figured no warranties on shells so never shipped anything in. Would have been a lot of weeks without flying phantoms due to shipping for cracks. So this time I figured, glue the whole **** shell so the screw holes are no longer important for structural integrity and see if DJI can figure out just what the hell is going on. This time the cracks are on main screws holding top to bottom instead of the motor screws so it's a different situation.

 

[bighi]

Yeah, the zip tie thing. You're better off just holding by hand unless you keep that zip tie well away from where you are gluing. Mostly I used hand pressure. But you know, you don't really need any pressure since the glue will work into the seam and do its job anyway. A little bit of pressure, on and off, just helps wet all the surfaces to be bonded. About thirty minutes ago I finished gluing the entire back seam. But this time around I waited too long to wipe the excess and it looks a little sloppier. But still not very noticeable. Here is a pic. I gotta drive to my apartment in Italy tomorrow for two weeks of flying over the Adriatic. I would rather be flying than tracking repairs, shipping and ******** of this sort. So I have no choice other than to glue. I will post what the results are after flying. Again, no tree hitting crap. Just 100 - 120 meter high, 500 - 1500 meter away flights over sea water. It's a far safer place to fly in case of all out systems failure. To each his own but I prefer to fly over water or alps.

 

[PropDr]

All the pictures show the cracks in the screw pockets of the lower shell.
This is a injection molded part; so, if only some units have the problem I would be looking in to the injection process, if all have the problem it is a mold design problem.
I will not be able to put my hands on my P3P until July 2 (working in Australia), but I will be looking at the screw pockets for injection flaws.
I also ordered some 1/2" wide gold mylar tape to wrap that area to enhance load transfer to the upper shell.

 

[Bluethundr]

It has to be torque on the assembly line, there is no way under normal flying conditions this can happen. I work with plastic all the time and this is not from normal wear and tear. I agree they could increase the thickness but this is excessive to say the least.

Are you guys using any kind of cleaners or solvents?

Nope...no cleaner or solvent. Just a paper towel with light soap and water for the bug kills. My 3 are just the small cracks, but after time of being unnoticed i can guarantee you that they would open up and be worse. On a side note, I glued the *hit out of mine. I don't have time to send it to DJI for a repair they will not cover under warranty. After the glue guess what?...Rock solid with no wobble. So take note fellas. If you see a wobble when she comes up to the 3.9 feet from take off/auto take off....you have CRACKS in those screw holes. I also reinstalled the firmware from the previous post, did a new IMU cal and compass cal and she was back to her old self. UAV STAYED in place, had a 12 mile cross wind. She would not drift at all or loose altitude. Now with the new app she purrs like a kitten.

 

[NoOne]

Nope...no cleaner or solvent. Just a paper towel with light soap and water for the bug kills. My 3 are just the small cracks, but after time of being unnoticed i can guarantee you that they would open up and be worse. On a side note, I glued the *hit out of mine. I don't have time to send it to DJI for a repair they will not cover under warranty. After the glue guess what?...Rock solid with no wobble. So take note fellas. If you see a wobble when she comes up to the 3.9 feet from take off/auto take off....you have CRACKS in those screw holes. I also reinstalled the firmware from the previous post, did a new IMU cal and compass cal and she was back to her old self. UAV STAYED in place, had a 12 mile cross wind. She would not drift at all or loose altitude. Now with the new app she purrs like a kitten.

What kind of glue did you use and where did you glue? I was thinking of using some Loctite 5 minute epoxy on mine on just the arm ends.

 

[tom3holer]

During the installation of prop guards today, I was questioning just how how tight these screws should be. Anyone have a torque wrench to measure the inch/pound?
But here's the real kicker: Two days ago I received my p3 pro and noted that the shipping box was partially crushed, and the gimbal bracket was disconnected inside the box. hmmm. I took some photos just in case and for the record. Called the distributor and followed up with an email to log the condition. He said as long as the foam insert was in place, all should be fine. I was going to fly today but the weather n/g. To my surprise, another p3 pro was delivered to my doorstep. Once I finish my maiden flight, and all is satisfactory, I will return one of these birds!
Ps. anyone know why DJI uses torx and hex fasteners? It would be nice to have a standard.

If by standard you mean Philips the reason for torx is that they are vastly superior in that they will rairly strip like Philips do on a regular basis.

 

[viewkopter]

This should a no brainer for DJI to fix but unfortunately, they don't give a dam when it comes to after sale service. The cracks happened simply by the factory over tightening the shell during assembly. On the flip side side the cracks are not dangerous and will not compromise you're overall flight experience, you might also want to open the the unit and add a flexible silicone based glue around the edge screw mounts in order to avoid further damage. If you are good with your hands you might consider replace the top shell cover.
Dealing with DJI is truly a frustrating experience, best of luck!

 

[NoOne]

I was getting ready to super glue the seams. Will this glue melt the plastic? It says not to use on polypropylene plastic. Anyone know what the shell is made of?

 

[fly-catchers]

Then you doing something wrong.. Even with my pig p2 w/ h3-3d running lightbridge at 7000', I didn't developed these crack.(I was running lightbridge 3m before release, FYI) Now I have seen these cracks forum after people have disassembled their units and or applying liquid thread lock. Thread lock is the most common cause. Over tightening being a close second. This is why dji does not recommend users opening the craft.

The ops post is more than likely a manufacturing error with the torque being set too high on the assembly line. DJI is already in the process of getting this unit back for study.

I have both a P1 and P2 which have developed these hairline cracks on the ends of the arms. In the case of the P1 I blamed myself as I had indeed opened the casing to fit a gimbal. But the P2 has never been opened or crashed and only hand caught on landing. Two cracks (one on the upper case and one on the lower case right by the philips screw have appeared after fewer than 10 flights. So either a weakness in the plastic or indeed over tightening at the factory. In both cases it should be covered by the guarantee. I have never applied any Thread lock- although there is already dry blue thread lock on the fitted screws. Nor have I applied any glue as I have read that certain types of glue can also cause the plastic to become brittle. Even before I got my P1 in September 2013 I had already read and seem examples of these hairline cracks- so the problem has been know a long time now. And its not always the customers fault!!

P1 crack. The P2 has two cracks on the same arm- one each on both casings!

 

[NoOne]

Ok so one day later and one flight, my screw hole hairline cracks are starting to open up and I can see black cracks now.

I really want to turn this in for a warranty repair but at the same time, don't want to be without it for 6 weeks.

I wonder if DJI would still fix it under warranty if I super glued the shell around the ends of the arms, when it's painfully obvious that the screw holes are defective.

Any glue suggestions? I'd really like to know what the shell is made out of so I could make an appropriate glue choice.

Blade, any comment?

It's still absolutely ridiculous that I have to glue together a one month old aircraft, but it is what it is......

To recap- I have not ever touched a single screw on this craft. Hand caught mostly, never crashed. I have only wiped it with a damp microfiber to wipe bugs off.

 

[blade strike]

Ok so one day later and one flight, my screw hole hairline cracks are starting to open up and I can see black cracks now.

I really want to turn this in for a warranty repair but at the same time, don't want to be without it for 6 weeks.

I wonder if DJI would still fix it under warranty if I super glued the shell around the ends of the arms, when it's painfully obvious that the screw holes are defective.

Any glue suggestions? I'd really like to know what the shell is made out of so I could make an appropriate glue choice.

Blade, any comment?

It's still absolutely ridiculous that I have to glue together a one month old aircraft, but it is what it is......

My suggestion is to contact dji tomorrow before doing anything.

 

[gingerbloke]

Like he said, he knows that DJI will BS him and then take 'til September to get his new toy back.

Very frustrating.

 

[bighi]

I have both a P1 and P2 which have developed these hairline cracks on the ends of the arms. In the case of the P1 I blamed myself as I had indeed opened the casing to fit a gimbal. But the P2 has never been opened or crashed and only hand caught on landing. Two cracks (one on the upper case and one on the lower case right by the philips screw have appeared after fewer than 10 flights. So either a weakness in the plastic or indeed over tightening at the factory. In both cases it should be covered by the guarantee. I have never applied any Thread lock- although there is already dry blue thread lock on the fitted screws. Nor have I applied any glue as I have read that certain types of glue can also cause the plastic to become brittle. Even before I got my P1 in September 2013 I had already read and seem examples of these hairline cracks- so the problem has been know a long time now. And its not always the customers fault!!

Those are the same cracks I've gotten in every P1 and P2 I've owned. P3 is different. Or at least so far has been different. With the P3 it's been at the screw holes between the lights and motor area.

 

[bighi]

My experience as far as sending to DJI or when I take into account two P2s bought in January this year, with both having cracked, is that I would have barely flown had I sent anything in. Right now I'm down in Italy and the weather is ideal for flying. If I thought that this is an rare case, I would have sent it in. But with three cracked phantoms, three out of three, I am still not convinced that this is rare. Not in my case without any crashmor hard landing. Hand catch every time. Right now I'm testing the result of gluing the seam between top and bottom. Something I would never do on P2 but with the non modular internal P3 I have no problem doing. Also, the cracks on P2 were impossible to repair without opening the shell. Not on P3 since they, so far, are all happening away from the motor area. So far three flights are done, 120 meter altitude, 2 km distance over the Adriatic. No more crack spread, no loss of structural integrity so far. Also, restored shell stiffness can actually be seen with less wobble on descents. Maybe, just maybe, DJI, which already does not want end users opening phantoms, should look into keeping the prices low on shells and at the same time deliver new phantoms with bonded shells. I know this is not acceptable to some but it does work, so far, quite well in preventing chassis failure. After all, an egg is far stronger than the same egg with screws holding the top and bottom together. Here's a picture from the last flight. No mickey mouse flying around trees testing here.

 

[NoOne]

Bighi- what kind of glue did you use?

I would like to know what kind of glue is safe for the shell.

 

[FredSheldon]

Bighi- what kind of glue did you use?

I would like to know what kind of glue is safe for the shell.

Here's what we use on Plastic RC boats and it works great. Never had to use on the P3 so can't vouch for using it on them. Gorilla Glue: http://www.gorillatough.com/

 

[NoOne]

I'm guessing that an epoxy would be most appropriate.

I'll ask again, does anyone know what the shell is made of? My guess is polystyrene.

Blade?

Thanks in advance.

 

[bighi]

I used standard super glue by Loctite. So far so good but I'm curious about gorilla super glue.

 

[bighi]

I just finished doing a night flight and again was amazed by the lack of wobble on descent after restoring the structural integrity. So for whoever has the cracks on one or both of the two side by side screw holes, the difference in performance can be rather substantial depending on flying situation.