I Can't Believe it! MY "New & Improved" shell has a crack after 7 flights!

About 1 out of 4 DJI props are extremely close or exactly balanced according to my Dubro. 1 out of 4 DJI props take almost an act of God to get balanced (sand, sand, sand and sand some more), some suck!
The DJI pros are pretty good and pretty much balanced. The original DJI props dont need to be balanced, the differences wont matter at all. Its maybe good for fake china carbon props. Balancing will make it worse because the rods are never 100%. I have 4 rods and all 4 show 4 different results on the dubro, this is the proof that balancing is a no go. Better keep it in stock or you make it all worse and the placebo effect kicks in. The reason for the cracks are bad design, materials, temperature and probably the motors used. There is a reason changing to lower rpm motors, the old P2 concept with the 3S was better.
 
I disagree. Advising to not balance props because the prop balancers don't work can lead to unnecessary vibration from a badly out of balance prop. Your anecdotal report of the 4 rods in your balancer isn't proof of anything in my opinion. Proof is not met with such a small sample. I'm just receiving my 6mm rod today so we'll see what it shows. Metal rods manufactured for balancing are much more likely to be in reasonable balance than a plastic propeller. These props do look to be higher quality than your typical APC electric props that always seem to need balancing.
 
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Arrrgh this whole prop balancing is annoying. I mean there's arguments for both sides meanwhile some of us(like myself) are in the middle and I'm a guy who likes data and answers. So here are my main questions:
Is there proof any way that balancing props will help.
Is there any phantom that we know for sure were cracked by unbalanced props
How do we know if this isn't just a 1% issue with shells
And lastly if your not that experienced with quads or props in general and aren't having issues, how the hell can you tell if they need balancing?
I'm not against one way or the other, I just wanna keep my bird in the air as long as possible so I just want facts one way or the other.
 
I disagree. Advising to not balance props because the prop balancers don't work can lead to unnecessary vibration from a badly out of balance prop. Your anecdotal report of the 4 rods in your balancer isn't proof of anything in my opinion. Proof is not met with such a small sample. I'm just receiving my 6mm rod today so we'll see what it shows. Metal rods manufactured for balancing are much more likely to be in reasonable balance than a plastic propeller. These props do look to be higher quality than your typical APC electric props that always seem to need balancing.

I just go a Du-Bro 499 yesterday and used it to check the balance job I did earlier on a Speedy Prop balancer. It confirmed the Speedy balance, but was much easier to use than the Speedy. I then balanced the other 4 props that came with the P3 and all but 1 were close--not perfect. One however was extremely far off at the hub. This was the first prop to need hub balancing. It took a lot of weight to balance the hub and as a result, I will most likely never use that prop. Today I'm picking up the Dji CF props and we'll see how they look. (What do you think--way too much time on my hands?)
 
Arrrgh this whole prop balancing is annoying. I mean there's arguments for both sides meanwhile some of us(like myself) are in the middle and I'm a guy who likes data and answers. So here are my main questions:
Is there proof any way that balancing props will help.
Is there any phantom that we know for sure were cracked by unbalanced props
How do we know if this isn't just a 1% issue with shells
And lastly if your not that experienced with quads or props in general and aren't having issues, how the hell can you tell if they need balancing?
I'm not against one way or the other, I just wanna keep my bird in the air as long as possible so I just want facts one way or the other.

So spend $50-60 and get a Du-Bro, a 6mm balance rod and StrongArm reinforcement plates. Or, if you don't enjoy tinkering, just fly it as is. It will probably crash long before any cracks would/could ever make a difference. IMO, of course.
 
So spend $50-60 and get a Du-Bro, a 6mm balance rod and StrongArm reinforcement plates. Or, if you don't enjoy tinkering, just fly it as is. It will probably crash long before any cracks would/could ever make a difference. IMO, of course.
In about a month and a half, our average high will be about 20°F, I'll have plenty of down time to tinker and $60 isn't much. As far as the arm reinforcements, I have guards on my P3A so how would that work out(btw still no cracks I recently checked) wouldn't one be in the way of the other?
 
In about a month and a half, our average high will be about 20°F, I'll have plenty of down time to tinker and $60 isn't much. As far as the arm reinforcements, I have guards on my P3A so how would that work out(btw still no cracks I recently checked) wouldn't one be in the way of the other?

I don't know about the prop guards. Aren't they mostly for indoors? Some have said they are worried the guards further add to the forces that may be causing cracks. But I see StrongArm has a model made to work with prop guards. There is a lot of info on their website: Strong Arm reinforcement plates
Hope this helps.
(I too will only be flying off my back porch in Colorado this winter)
 
Just buy a shell and do it yourself. Swap your motors and solder bullet connectors on while you're in there. At least that way you can be sure you're using the new shell. And do start using strong arm plates.

If you are suggesting replacing the motors and shell with the new version, you must also replace the central board #33 with the compatible board #96. I can't find a price for the new board, but the old #33 board is $399 US. So that route is basically out of the question. Plus 3 hrs labor if all goes well.
See this article from the Dji website:
Compatibility Notice for New Phantom 3 Professional/Advanced Motors | DJI
 
Curious, how long did it take you to replace the shell? What happened?
I took mine apart after a crash and straightened it because shells weren't available back then. It's actually straight enough I won't need a new shell till the next event.
Your replacement job was obviously a success.
 
Arrrgh this whole prop balancing is annoying. I mean there's arguments for both sides meanwhile some of us(like myself) are in the middle and I'm a guy who likes data and answers. So here are my main questions:
Is there proof any way that balancing props will help.
Is there any phantom that we know for sure were cracked by unbalanced props
How do we know if this isn't just a 1% issue with shells
And lastly if your not that experienced with quads or props in general and aren't having issues, how the hell can you tell if they need balancing?
I'm not against one way or the other, I just wanna keep my bird in the air as long as possible so I just want facts one way or the other.

There are no facts which point toward prop balancing doing any good with the DJI factory props. It's like prayer - lots of people will tell you it works. One religious billionaire commissioned a study - and it didn't work.
BUT, being a mechanic myself I do know that when I spend some time on a process - I feel good about the piece of equipment. It's like getting an oil change in your car - even if you didn't need it you somehow think the car is running better and thanking you for the attention!

IMHO - and I do this (check this industry) for a living, the shell problem is somewhere between 2% and 10%. But even those figures don't mean anything because it's more a matter of the ## of hours flown and the conditions that were flown in. It also could related to rough handling of the birds in packing and shipping and other things. Many users may have cracks and never notice them - etc.

But, again IMHO, I suspect the shell design was "just good enough" and that the vendors and/or tooling (or formula/heat, etc. used to form) were responsible for some bad runs.

Also, the P3 - being so much more capable than former models - tends to get used a lot more. It works better in wind and other conditions so it's subjected to more hours of flight time and more stresses.

I've owned a lot of Phantoms and you won't find me ever balancing a prop.
 
There are no facts which point toward prop balancing doing any good with the DJI factory props. It's like prayer - lots of people will tell you it works. One religious billionaire commissioned a study - and it didn't work.
BUT, being a mechanic myself I do know that when I spend some time on a process - I feel good about the piece of equipment. It's like getting an oil change in your car - even if you didn't need it you somehow think the car is running better and thanking you for the attention!

IMHO - and I do this (check this industry) for a living, the shell problem is somewhere between 2% and 10%. But even those figures don't mean anything because it's more a matter of the ## of hours flown and the conditions that were flown in. It also could related to rough handling of the birds in packing and shipping and other things. Many users may have cracks and never notice them - etc.

But, again IMHO, I suspect the shell design was "just good enough" and that the vendors and/or tooling (or formula/heat, etc. used to form) were responsible for some bad runs.

Also, the P3 - being so much more capable than former models - tends to get used a lot more. It works better in wind and other conditions so it's subjected to more hours of flight time and more stresses.

I've owned a lot of Phantoms and you won't find me ever balancing a prop.

You're a mechanic--what would you say about balancing a new tire? It may not need any weights, but wouldn't you want to check?
And I agree, doing little things like this make us feel closer to our aircraft.
 
Is there proof any way that balancing props will help.
Anything that rotates, especially at a high rate of speed, is more stable, more free spinning, and transmits less vibration. All of those factors play a role in anything that flies! Cut a chunk out of a blade of a box fan and try to tell me that it runs just as well afterward!
Is there any phantom that we know for sure were cracked by unbalanced props
There is likely no way to ever know this for wusre. The only way would be to force one to crack with an out-of-balance prop. But then the argument would be that it was set up. Its a no brainer that vibration breaks things. Sound shatters glass at the proper frequency. Steel will shatter the same way, under the proper conditions. So its hardly far fetched to EXPECT plastic to break at the right frequencies as well.
How do we know if this isn't just a 1% issue with shells
Unless you work for DJI, you will never be able to definatively nail this down. All we can go by is the data we do have and some basic math
And lastly if your not that experienced with quads or props in general and aren't having issues, how the hell can you tell if they need balancing?
Refer to answer # 1
 
You're a mechanic--what would you say about balancing a new tire? It may not need any weights, but wouldn't you want to check?
And I agree, doing little things like this make us feel closer to our aircraft.

By mechanic I mean I look at everything mechanically.
I can build a house, work with sheet metal, electric, plumbing, quads and most other things.

I'd consider balancing props on a homemade quad with aftermarket props - but the QC on the Phantom props has proven itself (IMHO) to be quite good.

I do have experience with other quads and how the props vibrate and look when they are out of balance or the shafts are bent, etc - that's a different matter.

DJI has 100's of engineers - many of them aeronautical specialists. If they wanted us to balance the props they'd probably say so.
 
Go buy any prop and tell me what the instructions say that came with it

Sent from my SM-G920P using Tapatalk
 
Why would you fly without balancing props? I came from the build world and it was unheard of to fly with unbalanced props. I'm guess that is I have one of the first P3P's with tons of flights and no cracks. I have no idea if there is a correlation but I thought it was required with all quads. I ordered the prop balancer when I ordered my P3P.

PS. two of my props were way out of balance whet I received them.
 
Anything that rotates, especially at a high rate of speed, is more stable, more free spinning, and transmits less vibration. All of those factors play a role in anything that flies! Cut a chunk out of a blade of a box fan and try to tell me that it runs just as well afterward!

There is likely no way to ever know this for wusre. The only way would be to force one to crack with an out-of-balance prop. But then the argument would be that it was set up. Its a no brainer that vibration breaks things. Sound shatters glass at the proper frequency. Steel will shatter the same way, under the proper conditions. So its hardly far fetched to EXPECT plastic to break at the right frequencies as well.

Unless you work for DJI, you will never be able to definatively nail this down. All we can go by is the data we do have and some basic math

Refer to answer # 1

I agree with everything you said. Working with a good balancer like the DuBro or the Speedy, there is no question you will have good verifiable results. Most of the Dji props I've balanced were close, but all needed a little adjustment--some more than others. And don't forget the satisfaction you get improving things.
 
The props are balanced generally speaking but the hubs are usually way off
See... THATS where the problem lies. Not the hubs! The "generally speaking" mentality. Yes, the pprops are balanced pretty well most of the time. But "pretty well" is not perfect! "Pretty well" is not properly!

I know its not exactly the same, but its very similar... I come from far too many years of rotor wing aircraft maintenance. Ive balanced the head of countless hundreds of rotor systems in my years! In that process, there are times when 1/4 oz would make a 16000lb aircraft shake like mad, at certain RPM, or certain blade stress levels. And that 1/4oz is mounted about 1/5th of the way from the center of the hub, delicately, yet perfectly, balancing nearly 2500lb of rotating weight. I dont care who you are! You will NEVEr be able to back a statement centered around something like"balance doesnt matter", or "it cant cause cracks", or "they are good enough"! We dont fly over people because it could be dangerous. But some want to say they dont care about balance because it not important? If you cant AFFORD a balancer, then use that as your excuse! If you dont know HOW to use it, then ask!
 
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Anything that rotates, especially at a high rate of speed, is more stable, more free spinning, and transmits less vibration. All of those factors play a role in anything that flies! Cut a chunk out of a blade of a box fan and try to tell me that it runs just as well afterward!

There is likely no way to ever know this for wusre. The only way would be to force one to crack with an out-of-balance prop. But then the argument would be that it was set up. Its a no brainer that vibration breaks things. Sound shatters glass at the proper frequency. Steel will shatter the same way, under the proper conditions. So its hardly far fetched to EXPECT plastic to break at the right frequencies as well.

Unless you work for DJI, you will never be able to definatively nail this down. All we can go by is the data we do have and some basic math

Refer to answer # 1
Thanks for the breakdown of answers, it's appreciated. I did pick up a prop balancer recently and found 1 of my blades was not very well centered. So after a quick stop on you tube I did a little sanding and was good. You're fan analogy makes a good point and kinda does have the oil change feeling as well. And while a test flight was out of the question due to crappy wind conditions, I did get a hover test in for about 5 minutes with no problems.
 
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