Dji Mavic Pro Carbon Fiber Quick Release Propeller Props

[CactusJackSlade]

Has anyone heard of "If it ain't broke, don't fix it" ?

Exactly.... but they do look pretty cool Actually I do love my 12" CF Tiger Carbon props on my AD-1.... it does make any bird look pretty sweet. Of course you are hard pressed to beat the quality of Tiger CF props... and they better be at $30 EACH

 

[Mavzn29]

It seem there is lots of guessing and myths out there about CF blades. Here is some background that I want to share with Mavic and other drone owners. First CF blades became very popular with RC helicopter pilots. Those CF blades considered much superior and must have compared to wooden blades on helicopters especially for 3D stunt flying maneuvers. CF blades are rigid and and because they are fairly long on helicopter, you get much better (faster and precise) response from controls. In terms of strength, CF blades are stronger, allowing heli pilots to run at higher engine RPMs, again improving 3D stunt performance and provide much higher possible G loads during stunts like recovering out of free fall or performing tight loops. Here is where it becomes muddy water for Done and CF blades usage. On helicopters, pilot can adjust controls response by changing throttle curves, blade pitch curves, RPMs and overall system gain (how fast system responds to pilot's input). On drones, Mavic, flight characteristic are controlled by flight computer and not user adjustable. Its not even clear if flight computer can learn that CF blades provide quicker response than flexing original ones to take advantage of improved flight characteristics. If Mavic system gain not adjustable by learning in flight computer, then there is no benefit to CF blades in term of response time. And lastly, Mavic is not a stunt performing machine, I am still trying to figure out how to do loops and fly inverted on it Therefore biggest benefit becomes weight, looks and resistance to minor damage.

 

[Quad808]

*Mavvzn29 makes great points, along the lines of my experiences with quads and hex copters*

Here is my experience with CF props. I build my own drones and some have carbon fiber props, some have carbon-mix props, and some have the DJI 9" phantom self tightening props. Other brands of plastic props have been worthless as compared to the same size DJI props. I balance all my props.
Full CF props typically give you more lift and response, because they don't flex. The downside to this as Mavzn29 posted is the FC has to made adjustments faster, due to the quicker response to motor thrust. I have built several Quads and Hex copters that perform great with CF props, and some that can't hold a stable hover BECAUSE of the carbon props. It depends on the bird, motor size, weight etc. High KV motors means faster response as compared to lower, more efficient KV motors. I use CF props on all my low KV birds, the largest being 18" CF props. (1200 HEX, BEAST of a bird)
I have tried all sorts of props on my drones. The best props, bar none - and I resisted for a long, long time are the DJI 9" self tight props for performance and smoothness on the appropriate sized bird, hex or quad. This tells me of the quality and engineering that went into DJI props.
So what does this have to do with these props?
For a camera bird, I do not use CF props, unless it's on a hex...for smoothness of the drone in flight, you need some flex in the props - so response from the motors are dampened a bit, like the stock DJI props on the Mavic. For all around props, I like the carbon mix props. Not as much flex as plastic, but more flex than CF props.
So bottom line from my experience is:
if I want a bit more performance, (response) and possibly squeezing out a bit more flight time, I would switch to CF
if I want smoother flight, I would just stick with the DJI props.

This is a camera bird, high kv motors, so you need a bit of "give" in the props to dampen response. I won't be switching to CF unless the data shows otherwise.
Just my opinion based on experience, not having used these particular CF props on my Mavic.

 

[Metal69rock]

Here is a good comprehensive video about Mavic CF props. Enjoy. [emoji1360]

 

[cderoche]

So did anyone test them out and see if you get longer flight time? Would be my sole interest in CF props on a Mavic? In that video they weighed more than the stock ones, but the guy just mentioned some advantages over stock, more light, less vibrations, etc, but no data to back it up. Even if they have more lift, with 1g more weight a piece is that more lift enough to see a worth while gain in flight time?

 

[Rbruz]

Here is a good comprehensive video about Mavic CF props. Enjoy. [emoji1360]

The props in this vid are not Carbon Fiber They are injection molded plastic and maybe infused with cf

 

[Robbyg]

I have zero experience but have two questions.

1) If one of these props should by chance hit into a person or my finger will the carbon fiber do a lot more damage?

2) When the craft quickly accelerates the force is transferred to the frame. The weak point is the arms folding joint which actually flexs. I would imagine that the regular props flexing act to absorb some of that energy. Since the CF props do not flex much do you think that more stress is being transferred to the folding joints? I already have creaking sounds in one of my folding arms from doing sudden acceleration and braking and I don't want to make it worst.

Rob

 

[Rbruz]

The props in this vid are not Carbon Fiber They are injection molded plastic and maybe infused with cf

This is what a true carbon fiber prop looks like, the ones he shows are plastic with carbon powder makes the plastic stiffer for sure, HQ makes most of these. Guy that owns HQ used to injection mold all of VW stuff where he worked for years left that and started up the drone prop business. Great props he makes.

 

[Mad Mavic]

@Anthony:

As I am not an aeronautical engineer - I would love to hear from someone on this topic and read their input.

I do however - tend to think that since these types of props depend on centrifugal force to align the props during flight - I would 'think' that if they were precision and balanced the carbon fiber would yield the following benefits:

1) Less 'flexing' of blades would yield less vibrations and also lend to perhaps a more 'stable' hover.
2) Quieter VS Louder - there is a 'decibel' measuring APP that could be used to verify if there is any changes or differences in using carbon fiber versus stock DJI plastic blades.

There is a boatload of 3rd parties that sell carbon fiber blades for Phantoms, etc. - so I tend to think that perhaps there is some tangible benefits to using carbon fiber blades.

As for causing damage to the motors upon hitting something while flying with carbon fiber blades - I suspect that either way - carbon fiber or not - no crashing of blades in something is good to the motors, including the aircraft itself.

It would be beneficial to hear more pros or cons on this blade issue - especially of the pros outweigh the cons in favor of say - stability, battery life, decibel/sound, etc.

Hello BCMoto. Sorry for jumping in the middle of an archive but I wanted to add to one segment off your post. .I studied Aerospace Engineering but but not a lot of knowledge in your field, except perhaps for basic aerodynamics, and a brief overview of suck-squeeze-bang-blow..

I wanted to add a brief comment in reference to your mention of damage to the aircraft when using carbon fiber props. I'm on my second set, and thus far I have compiled a small amount of data with respect to noise, and flight time, but damage is what I see is more important.

I've encountered a several prop strikes; all of which required prop replacements. All revealed their weak link after the strike. It seems the weak link on the carbon fiber, is between the blade and the locking mechanism on the motor Ill call this the "center hub".(I fly a Mavic Pro Platinum) This center hub attaching the two blades together, is made from some type of plastic. Not sure if glass reinforced, but definitely not carbon fiber. The "hooks" that lock the hub to the motor are the weak link, and fortunately only one of these has broken on both prop strikes; leading be to believe it could be a design feature. Should all three hooks fail, sending the propeller spinning off, i'm thinking there wouldn't be enough logic in the control to maintain straight and level attitude with three props... someone out there has that answer.

as someone has already stated, the carbon fiber props don't flex, thus displacing a greater volume of air per revolution, equating to a greater distance per percentage of battery. The carbon props are giving me 1 mile distance over the quiet OEM props that the Platinum is know for. However, the weak link after a prop strike on the OEM blades has been the blade itself, as opposed to the hook; obviously due to the differences in blade materials. Also the OEM props brake randomly. Sometimes on the leading edge, other times the trailing edge.Interestingly enough, the Mavic will maintain straight and level flight attitude with an inch cut off the ends a prop: see on youtube

My gut feeling is the carbon props are better for distance flying but that's about it. For some reason I just feel a catastrophic failure is emanate if I keep flying the carbon fiber props. Aside from the weal link being the hook, which by the way, falls into the motor cavity, and only by grace have I not had a motor lock up in mid flight, the mass of the carbon fiber at rest, is greater than the OEM props. Thus increased mass/inertia contained by the same size Jesus Nut

Hope there was something helpful in that

 

[quick_dry]

Should all three hooks fail, sending the propeller spinning off, i'm thinking there wouldn't be enough logic in the control to maintain straight and level attitude with three props... someone out there has that answer.

it will just tumble to the ground. You can't really control a quad that has lost a prop - we could if there were fully reversible pitch props and ESC. 2 motors turning in the same direction will tend to spin the craft around - if the motor diagonally opposite the broken motor can immediately stop or run itself in both directions to counter roll around the axis along the motor pair that is working.

Something like an Inspire 2 can more likely stay in the flat spin rather than tumbling, because it has so much hanging down underneath. A mavic has nothing to really provide a righting moment like a keel on a boat.

 

[westonmavicpilot]

and a brief overview of suck-squeeze-bang-blow..

Whoa, that sounds like an entirely different topic that shouldn't be covered on a family friendly drone forum!!!!

 

[Mad Mavic]

Whoa, that sounds like an entirely different topic that shouldn't be covered on a family friendly drone forum!!!!

LMBO well it is a little weird sounding for a turbine engine ignition system.