Triple bladed propellers

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Hello to all,

I'm not entirely new to drones, but I have a question regarding fitting 3 bladed propellers to a P3A
.
Has anybody tried them?

Did they add any speed, particularly an increase in height speed?

Did they maintain the drone's stability?

Did they decrease flight time?

Best regards,
 

Meta4

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I have a question regarding fitting 3 bladed propellers to a P3A
Has anybody tried them?
Lots of people
Did they add any speed, particularly an increase in height speed?
Did they maintain the drone's stability?
Did they decrease flight time?
No appreciable improvement of flight performance.
Low quality props can cause serious problems, 3-bladed props can be harder to balance.
DJI engineers put a lot of effort into designing a tuned propulsion system with matched motors, ESCs and props.
Slapping on some aftermarket prop isn't likely to give a significant improvement.
 

msinger

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I'm not entirely new to drones, but I have a question regarding fitting 3 bladed propellers to a P3A
.
Has anybody tried them?
You'll find lots of threads on that topic if you search here.

I don't recommend anyone use them. OEM DJI props were designed for the Phantom and work very well.
 
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Did they add any speed, particularly an increase in height speed?

Speed is controlled not by prop but by Flight Controller. The 6 axis system will monitor and adjust ... so there is no real benefit.

Did they maintain the drone's stability?

Why should they do any different - again this is all down to Flight Controller which adjusts motors rpm to achieve speed / direction / stability based on the inputs it receives.

Did they decrease flight time?

Unless you adjust prop diameter / pitch to match the OEM props thrust etc. ... if you use similar diameter / pitch - they will most like reduce flight time due the greater effort to get three blades 'cutting through' the air. The reduced RPM of motor will likely drop motor into a less efficient RPM range ..

As others have said - the OEM props have been designed for best compromise ...
 
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As has been said, the power train in the drone is a balanced system, ESC, motor and propeller all being calculated to produce optimum performance.

Most noise from a propeller is generated at the tips so one advantage of a three bladed prop is that they are quieter at the same thrust as they not only rotate slower but are also a smaller diameter thus greatly reducing the tip velocity.
 
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As has been said, the power train in the drone is a balanced system, ESC, motor and propeller all being calculated to produce optimum performance.

Most noise from a propeller is generated at the tips so one advantage of a three bladed prop is that they are quieter at the same thrust as they not only rotate slower but are also a smaller diameter thus greatly reducing the tip velocity.

The system comment - yes absolutely as I mentioned earlier. The Flight Controller takes the Pilots command and interprets to control motors ... speed / height etc. are all subject to programmed limits.

But on the subject of noise of props ... the blade shape actually determines most of the noise ... I agree that tips can and do go literally supersonic to create noise ... but in reality - the shape of blade is the major factor.
A 3 blader does not automatically add 50% thrust or performance ... in fact if porrly chosen - can be same or less than a 2 blader. A well chosen 3 blader will usually add about 20 - 30% thrust only. Its evident when thrust testing models and you find that the generally accepted guideline of -1 on diameter or -1 on pitch actually does not yield expected results. It is not unusual to find similar size 3 blader as a 2blader on the low to moderate KV motors.
 
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Thanks to you all.

It's been quite interesting reading about a prop's aerodynamics.

It's also interesting that Spitfire's were given a 3 bladed prop in early 1940 (as the Mark II), which allowed them to climb faster, although the blade was two-pitched.

I seem to remember my father (he used to be a RAAF pilot) saying the 3 blades continued until the aircraft finally retired.

Regards to all and take care during the holiday break.
 

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