P-4 Carbon Fiber blade failure

[Rotax Rick]

I purchased a set of P-4 carbon Fiber blades & the hubs that come with them for $119. I purchased the blades to get rid of the spring setup, plus there lighter & stronger with less flex & that should help in my range . I had around 2 hours on them. I never hit the blades on anything . I went to takeoff & the P-4 Drone started to roll over. I tried again & the same thing. I calibrated the compass . Same thing. Then I got a warning loose or missing propeller. One of the hubs broke loose to the bond that attaches them to the blades. You could hold the center hub & rotate the blade. I'm so lucky. I fly my first 1 1/2 mile on takeoff & landing over a giant lake.

 

[frankd32]

I signed up for the classes and information on droneU.com and during one of the classes for the part 107 test the guy specifically says do not ever use carbon fiber props on your DJI products.


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[rleigh]

I signed up for the classes and information on droneU.com and during one of the classes for the part 107 test the guy specifically says do not ever use carbon fiber props on your DJI products.


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Did he say why?

 

[Kirby Johnson]

There have been volumes written on here about NON-DJI props..Carbon fibre, three blade, etc. etc. Reminiscent of the NASCAR drivers pulling out of the pits without a set of lug nuts. It was the lug nuts fault.

 

[F3honda4me]

When you change props, you are also changing the load on your motors. The prop material, size, pitch, and even flex, will all change flight characteristics and amp load being drawn. It could be harmless or it could cause failures including ESC/motor failure. You should never use non DJI props on their drones.

 

[frankd32]

Did he say why?

Yes it was something about the vibration. I can go back and get more details for you in the next couple days.


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[rleigh]

Yes it was something about the vibration. I can go back and get more details for you in the next couple days.


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I only wondered just because I know DJI has their own Carbon blades they sell. I would never buy aftermarket parts that are the main and probably the weakest part that keeps it in the air. With that said, carbon fiber is one of the strongest material out that and light weight. But I can see if they are unbalanced that it could cause issue and faster wear and tear on the motors.

 

[Rotax Rick]

It wasn't a balance issue or anything to do with carbon fiber props. It has to do with poorly built carbon fiber props. There lighter, hold the airfield shape better & you get rid of the P-4 springs . ( Really I don't think the springs are a issue )
But when the center drive hub breaks look from the blades that is just a poor product. I feel DJI & anyone else discouraging carbon fiber props is for the idiot factor. They will cut off your fingers faster .

 

[Rotax Rick]

These props came from Drone World . They sell there $2700 Falcon P-4 with these props. I learned my lesson & I hope others will take note.

 

[Rotax Rick]

I'm going to say one last thing, As far as motor load as long as all blades are equal
in weight & shape you will not overload or under load your engine. Carbon fiber props are far better when built the correct way. They have a thinner airfoil & a better lift ratio than the Plastic props. They will cut your fingers off faster . But the small gain is not worth any benefit if there not made correctly. So going to carbon fiber is not a bad thing but WHO makes a good set. If DJI does then I will but them.

 

[Rotax Rick]

I have one question your more experienced drone pilots may be able to answer.
Can a Drone fly with a loose or missing blade once in MID FLIGHT ?????
It's had to believe I was so lucky to have just landed & on the next take off on the next flight it wanted to roll over & not fly at all.

 

[Testman]

No.

 

[toddff]

Carbon fiber doesn't flex as easily. This lack of flexing puts out micro vibrations into the frame and components. This can loosen screws and interior parts. You should check your airframe frequently if you do use them. They can even get damaged and you can not see the cracks and during flight, they break.


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[Rotax Rick]

Great Advice !!!!!!!!! Thank You. I'm sticking with the OEM blades from here out.
An Aerobatic Aircraft with very strong & stiff wings do take a far hard beating in rough air & so does the airframe . Look out the window of a Airliner & you can watch the wings go up & down. SMOOTH RIDE !!!!! I'm sure the OEM blades do the same think.

 

[jakobe75]

I signed up for the classes and information on droneU.com and during one of the classes for the part 107 test the guy specifically says do not ever use carbon fiber props on your DJI products.


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If they arent reccomended, Why does DJI still sell carbon fiber props for their own products?

 

[jakobe75]

Carbon fiber doesn't flex as easily. This lack of flexing puts out micro vibrations into the frame and components. This can loosen screws and interior parts. You should check your airframe frequently if you do use them. They can even get damaged and you can not see the cracks and during flight, they break.


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Would wobbly soft plastic blades add more vibration? Would softer plastic would have more issues with balancing?

 

[F3honda4me]

I'm going to say one last thing, As far as motor load as long as all blades are equal
in weight & shape you will not overload or under load your engine. Carbon fiber props are far better when built the correct way. They have a thinner airfoil & a better lift ratio than the Plastic props. They will cut your fingers off faster . But the small gain is not worth any benefit if there not made correctly. So going to carbon fiber is not a bad thing but WHO makes a good set. If DJI does then I will but them.

But that's the point, they will not be equal because CF is not the same as plastic. You're changing things by using CF props. Things that could potentially cause a failure.

 

[F3honda4me]

If they arent reccomended, Why does DJI still sell carbon fiber props for their own products?

Because those props were designed for that craft. This isn't so much about not using CF, but more about using props that were not designed by DJI to operate with their craft.

But at the end of the day it's your money do what you want. Just realize that DJI will deny warranty issues if you have any failures. And they do know if you were using a prop that is not stock vs say a carbon fiber one. The information logged by the craft can show that a non stock prop was used. They actively check for this. There have been quite a few inspire 1 claims that were denied because they were using a popular CF prop that was not a DJI prop.

 

[AlecW]

Because those props were designed for that craft. This isn't so much about not using CF, but more about using props that were not designed by DJI to operate with their craft.

I'm normally Mr. Modify everything I buy but Phantoms seem so complicated to me I've decide stock is the way to go.

 

[jakobe75]

But that's the point, they will not be equal because CF is not the same as plastic. You're changing things by using CF props. Things that could potentially cause a failure.

But isnt that just speculation? Is there data to support that they will cause a potential failure....or even data to support they will have a postive impact?