Do Non-DJI Propellers Fly Well?

[With The Birds]

I think CFzone has possibly mistaken the coloured silver/black sprayed plastic as being metal/covering metal.
No, although I've never drilled one out/cut one up completely, I don't believe they do - they're just made totally from a composite plastic. I have some of them but don't want to waste one. However, feel free to cut one up one of yours completely to confirm it if you like!

It’s on the list of things to do. I haven’t managed to get an unserviceable one yet- they are surprisingly reliable.

 

[Steve7777]

Indeed, having thought a bit more about it, 'composite hub' is a bit of a misnomer as there is only one material (plastic), but it was DJI themselves who started using it to describe stock P3 propellers and that's also what most people here refer to them as.

 

[N017RW]

I believe they are CF reinforced plastic. If so, that makes them at least a two-part composite.

 

[With The Birds]

I believe they are CF reinforced plastic. If so, that makes them at least a two-part composite.

Nylon- DJI states the standard P4 props were CF reinforced (impregnated). Nice compound for the application.

 

[Hansolo1977]

Not even the most expensive ones will perform any better as it's the flight controller that governs how the Phantom flies.
Putting magic props on the Phantom won't change the parameters the flight controller allows.

But you've mentioned that the props you are looking at have metal hubs.
That's a potentially big problem because from the P3 series on, DJI have used dynamic braking for their motors.
That meant they had to abandon metal hubs for "stickier" nylon hubs to prevent propellers being thrown off in flight.
I'd suggest you also abandon them.

Props are a low cost item and are only worn or damaged if you use them for hedge trimming or crash landings.
Keep away from obstacles like trees and buildings and they will last a very, very long time.

That is not true props are considered crucibles in other words they fatigue and do need to be replaced that is a fact.Even real full sized aircraft need prop replacement due to nothing more than flight hours logged.If you want to do some research on it,Ikno props can look perfect even after many many hours of use but they do wear upon closer inspection good luck.

 

[solentlife]

Nylon- DJI states the standard P4 props were CF reinforced (impregnated). Nice compound for the application.

DJI props are based on the standard GFN .... Glass Filled Nylon ......

Master Airscrew
APC
Turnigy
Taipan

just to name a few of the many brands of props out there ALL using variations of GFN .... colour based on the Nylon used ... flex and resistance to thrust / torque based on amount of Glass filament embedded.

The props have ratios of the G to N to arrive at prime figures for job designed for. DJI would have contracted out to a prop manufacturer to provide a prop suitable for compromise use ...

All props suffer fatigue - but given the strength to construction ratio of our props ... its a factor that really does not come into it ... but damage does.

Nigel

 

[N017RW]

Here's a Press Release about DJI props.
Inside a Drone: Propellers

Seems they are unable to out-source to their satisfaction.

 

[solentlife]

All plastic based props are moulded ! Only wood props and similar are not.

The link in preceding post ... Inside a Drone: Propellers .. indicates DJI as cost cutting to be honest ....

There are many prop manufacturers of extremely high reputation that would produce for them ....

Sorry ... it reads as always .... Pure Marketing Hype ......

I have props of various sizes from 5x5 up to over 15" and have similar profile of blade and in similar GFN material ... from a number of brand names ...

No disrespect intended to poster ... NO17RW ....

Nigel

 

[N017RW]

The PR seems to correlate with the overwhelming report of problems with non-OEM props including so-called 'improved' and cloned/knock-offs.

 

[solentlife]

The PR seems to correlate with the overwhelming report of problems with non-OEM props including so-called 'improved' and cloned/knock-offs.

Maybe - but because it comes from them - it has to be read in the context of DJI covering its a**e ....

Read the * annotations in DJI manuals ! I have never seen so many 'get-outs' before !!

Nigel

 

[N017RW]

Comes from them?, You mean DJI???
If so you are mistaken.

The reports I'm referring to come from users here.

Non-OEM props have not been shown to perform as well as DJI's.

Those few users that seem to be in opposition use terms like 'seems' or 'feels' when describing perceived improvement and are likely subject to confirmation bias.

 

[Dennis 1]

Not even the most expensive ones will perform any better as it's the flight controller that governs how the Phantom flies.
Putting magic props on the Phantom won't change the parameters the flight controller allows.

But you've mentioned that the props you are looking at have metal hubs.
That's a potentially big problem because from the P3 series on, DJI have used dynamic braking for their motors.
That meant they had to abandon metal hubs for "stickier" nylon hubs to prevent propellers being thrown off in flight.
I'd suggest you also abandon them.

Props are a low cost item and are only worn or damaged if you use them for hedge trimming or crash landings.
Keep away from obstacles like trees and buildings and they will last a very, very long time.

As noted, the dynamic braking feature puts a lot of additional force on the props. Design engineers take things like this into consideration when they choose materials and attachment methods.
Like the person said, unless you are trimming hedges or maybe bouncing off of walls, props will last a long time.
While there are no published test results, I would expect that constant removal of the props after flight is a bigger threat to the DJI all plastic prop.
If the metal hub prop has the same ability to "stay on " then it is likely that the all-plastic prop was designed to improve profitability.
Graphite props could also be less susceptible to wear if they are being constantly removed.
Bottom line, it is all speculation until DJI publishes something official.

 

[With The Birds]

Comes from them?, You mean DJI???
If so you are mistaken.

The reports I'm referring to come from users here.

Non-OEM props have not been shown to perform as well as DJI's.

Those few users that seem to be in opposition use terms like 'seems' or 'feels' when describing perceived improvement and are likely subject to confirmation bias.

What about the fully sick total CF? Fully locked in, extra snappy and air gripping.....

 

[With The Birds]

As noted, the dynamic braking feature puts a lot of additional force on the props. Design engineers take things like this into consideration when they choose materials and attachment methods.
Like the person said, unless you are trimming hedges or maybe bouncing off of walls, props will last a long time.
While there are no published test results, I would expect that constant removal of the props after flight is a bigger threat to the DJI all plastic prop.
If the metal hub prop has the same ability to "stay on " then it is likely that the all-plastic prop was designed to improve profitability.
Graphite props could also be less susceptible to wear if they are being constantly removed.
Bottom line, it is all speculation until DJI publishes something official.

Speculation? We don’t need to wait for DJI to
publish anything, we already know from user experience the P2 metal hub props have a tendancy to fly off the P3 AC.

The properties of graphite are well known, one of them being in reducing friction, something we don’t want at the P3 prop attaching point. We also know that graphite promotes the corrosion of aluminium components- another undesirable property given the motor rotors and threads are an aluminium alloy.

The many users who have had hundreds of successful flights absent any issues with the prop hub threads suggest they perform very well.

As to manufacturing cost- forming threads in injection mounded components is typically achieved by having an unscrewing component in the mound. This adds considerably to tooling and and production comolexity and cost.

 

[Dronut2]

I'm not too concerned about performance, more on the cost side of things. They seem to be more flexible, and I have not tried to fly them yet. Also, that screw part of the propeller is all metal, no plastic. Do you think that would make a difference?

Metal on metal can cause stripping of the rotor shaft, especially with cross threading,whereas plastic will not damage metal, even with crossthreading.

 

[solentlife]

Comes from them?, You mean DJI???
If so you are mistaken.

The reports I'm referring to come from users here.

Non-OEM props have not been shown to perform as well as DJI's.

Those few users that seem to be in opposition use terms like 'seems' or 'feels' when describing perceived improvement and are likely subject to confirmation bias.

I linked your response to the earlier DJI write-up about lack of production for them to use ...

Nigel

 

[Steve7777]

Metal on metal can cause stripping of the rotor shaft, especially with cross threading,whereas plastic will not damage metal, even with crossthreading.

Given the pitch and thickness of the motor shaft thread, I would say that it's almost impossible to cross-thread a metal-hubbed prop onto the motor shaft thread, unlike when mounting a composite-hub prop, where it can easily happen. I've just tried with some metal-hubbed props and the only way I can see that it would happen is if you were to screw the prop on at an angle of about 45 degrees and then use a set of mole(vise)-grips to tighten it up.

However, yes - constant screwing and unscrewing of the prop could lead to fairly miniscule wear and shaving of the metal of the motor shaft or prop thread and that reason, and the other reasons stated, is why I use the method detailed in post #19 to fly metal-hubbed props on my P3P. There's also a lot less risk of overtightening, which could weaken or even destroy a composite thread, leading to a catastrophic failure.

 

[JamesT1950]

I purchased 2 sets of carbon fiber props for $15 just after I purchased my P3A about a year ago. They just seem to be more durable than the plastic ones that came with the quad. I balanced them when I got them and have been using the same set that I started with and have had no issues in almost a year

 

[68charger440]

I tried the cheapo props on my p4 and it flew pretty good, but It seemed to be just a touch shakier when holding position. Not enough to interfere with flying, but I was afraid the vibration would blur the pictures so I just kept them as emergency props and stick with DJI props. Maybe it was just in my head, but the DJI props are not that expensive to warrant taking a chance.

 

[solentlife]

I purchased 2 sets of carbon fiber props for $15 just after I purchased my P3A about a year ago. They just seem to be more durable than the plastic ones that came with the quad. I balanced them when I got them and have been using the same set that I started with and have had no issues in almost a year

I was using the same original first props of my P3S on my P3P .... well over a year old .... and the props that came with the P3P in the bag as spares.
I clipped a prop when I hit the tree - took a small chunk out of one blade ... that prop is in the bin. The others are relegated as spares and I finally took out the spares to replace ...
Unless you have 'incident' - the DJI props should last indefinitely ....

Just a comment - Decent CF Props are not $15 !! Yes there are plenty of 'budget' CF props ... but that's all they are ... budget props.
For example ... pal of mine pays over 100 Euros for a single two blade CF prop on his 3D model plane ... (22x10 size of course).

Nigel