Prop Test

[klawtrax]

Ok I have three kinds of propellers.

Original:



The DJI Carbon Fiber Reinforced:


The Tri-Carbon Fiber:


I did a sound test on each using the DB app on my iPad.

Original prop at idle next to mic = 68db


Original prop at hover 10 feet away = 73db


DJI Carbon Reinforced at idle next to mic = 71db


DJI Carbon reinforced at hover 10 feet away = 75db


Try-Carbon Fiber at idle next to mic = 70db
Try-Carbon Fiber at hover 10 feet away = 74db
Sorry, reached 10 photo limit.

I also did an ascending test. At idle, pegged the stick counted 5 seconds then read distance.

Original 18.6 meters.
DJI Carbon Reinforced 17.8 meters.
Tri-Carbon Fiber 18.1 meters.

Thought you guys might find this interesting.

 

[SteveMann]

What we mostly want is to increase our endurance. Anything else is secondary.
Try this test:
Start with a fresh battery, hover at ten ft. After a few seconds for the drone to settle, note the battery voltage and start your stopwatch.
When the voltage drops 2.0 volts, stop the timer.
Repeat. the more samples you get, the better the data.
Then do it all again with another prop.

 

[eBird]

Thanks for posting your prop test results. Although the statistical power is very low with an n=1 here, these results may in fact be generalizable. What I am most interested in is what you tested, prop noise. I hate how loud this thing is, makes me even more self conscious flying it.

 

[klawtrax]

I'm not that interested lol, I'd rather spend my time flying.

 

[klawtrax]

Yea I can hear my quad coming a block away.

 

[eBird]

How do those stealthy " black helicopters " get so quiet? Anybody remember Blue Thunder? It whispered.

 

[Tony Perry]

How do those stealthy " black helicopters " get so quiet? Anybody remember Blue Thunder? It whispered.

Blue Thunder wasn't real . At least not the "silent mode"

 

[klawtrax]

Sure it was, please don't screw up my fantasies!

 

[Chuck Young]

I used to work on the OH-58D and they are very quiet compared to other choppers. I had read it was because they had 4 main rotor blades and their rotor tips had less of a shockwave associated with them. The UH-1 Huey was a loud beast!

 

[splizaat]

Is there a real noticeable difference in performance/run time with the carbon blades vs the stock blades?

 

[FunN4lo]

Interesting. I don't see much difference in performance in the CF props. I have never tested/measured the sound, but I would swear my CFs are a little quieter. Maybe its just a different pitch

 

[ovyyus]

It seems inevitable that electronics and control gear will continue to increase in efficiency and decrease in size. It's probably only a few years before a drone with the capabilities of a P3P will be the size of a matchbox, and super quiet. I'd still like my P3P to be quieter now, though.

 

[eBird]

Blue Thunder wasn't real . At least not the "silent mode"

Oh yeah, sure. I suppose "Kitt" wasn't real either. "Hello Michael, your Phantom is operating at a high decibel level."

 

[Chuck Young]

It seems inevitable that electronics and control gear will continue to increase in efficiency and decrease in size. It's probably only a few years before a drone with the capabilities of a P3P will be the size of a matchbox, and super quiet. I'd still like my P3P to be quieter now, though.

Helicopter noise reduction - Wikipedia, the free encyclopedia

If you come up with some ideas I would be happy to check them out.

I did some calculations and at a hover the tip of the P3 props are running 75.4 meters/second, a far cry from 343 meters/second speed of sound.

 

[eBird]

I used to work on the OH-58D and they are very quiet compared to other choppers. I had read it was because they had 4 main rotor blades and their rotor tips had less of a shockwave associated with them. The UH-1 Huey was a loud beast!

You really should not be flying your Phantom so close to those helicopters, you'll give us all a bad name. [emoji6]

 

[Chuck Young]

You really should not be flying your Phantom so close to those helicopters, you'll give us all a bad name. [emoji6]

You know we never did figure out how to take selfies with R2D2.

lol

 

[flyNfrank]

What we mostly want is to increase our endurance. Anything else is secondary.
Try this test:
Start with a fresh battery, hover at ten ft. After a few seconds for the drone to settle, note the battery voltage and start your stopwatch.
When the voltage drops 2.0 volts, stop the timer.
Repeat. the more samples you get, the better the data.
Then do it all again with another prop.

Thanks for taking the time to post this info Steve. Based on 90% of the responses in this thread I'm not sure why most of them even entered to begin with.

 

[Chuck Young]

Thanks for taking the time to post this info Steve. Based on 90% of the responses in this thread I'm not sure why most of them even entered to begin with.

I for one am happy with the endurance so it is secondary in my book. I would like to see props that are designed to be silent. But since that won't happen I would at least like them to be much more quiet. Why does the thing need to be so loud you can hear a P3 flying 2000 feet away, sounds angry. We need a more friendly sounding P3, soothing like the gentle waves on a sandy tropical beach. It would be a whole new experience. I mean really, some of us want to film our subjects in a natural setting not squinting and trying to block the sun so they can hear where that "**** noise" is coming from or skittering away in fear like in the case of wildlife. Ninja props are what I want not something that will allow me to fly a thousand miles away.

 

[klawtrax]

Could the sound be from the high rpm's that are needed to keep that heavy drone up? Maybe bigger props and less rpm's? I don't know anything about this subject but I'm with you on the sound levels. I have to go really high if you don't want to disturb people outright.

 

[eBird]

I want pop out wings on my P3, so I can chop the power at altitude and float.