would be a great idea

That would be nice, i think it would be a good thing my noise level is out of the roof

Isnt it only the tips of the props that make the noise .

I like that noise.......especially after a disconnect and return to home.

It's a cool idea. Hopefully the engineers will consider it in the future.

Agree, I would like the option of a more quite UAV at times, but then other times that distinct noise can help ID your bird when seeing it may be iffy.  Also, I'd bet money that quitter props would likely result in a change in flight capability.  Likely you'd loose some speed and climb rate but you might get better flight time duration.

DJI Susan Posted at 2017-9-14 20:26
It's a cool idea. Hopefully the engineers will consider it in the future.

Aloha Susan,

     Three (or 4) blades with smaller radius will make for quieter props.  Also having the shorter blades will help keep the props more out of the picture when the Phantom tilts forward.

     Engineering can determine what lengths and pitch to put on the props to allow the same motors to be used.  Also some new tip designs can cut down on noise.  Not really that hard but the jig and mold work can be expensive.

Aloha and Drone On!

Genghis9 Posted at 2017-9-14 21:00
Agree, I would like the option of a more quite UAV at times, but then other times that distinct noise can help ID your bird when seeing it may be iffy.  Also, I'd bet money that quitter props would like result in a change in flight capability.  Likely you'd loose some speed and climb rate but you might get better flight time duration.

Not sure I want quieter props.  
While it sounds like an attractive idea, I worry about the lower noise level making the UAV a more attractive target for Angry Birds (couldn't resist).

I have seen birds fly uncomfortably close to my UAS's and I wonder if they might not seem quite so intimidating if they have 50% quieter props.
I know that the noise of those props 4 or 5 feet away from my head makes me want to keep a healthy distance.

Just a thought.

I like the sound my drone makes, it tell people stay away or then again attract them to my location, it sometimes impresses the girls they think you a real pilot.

ALABAMA Posted at 2017-9-14 11:51
I like that noise.......especially after a disconnect and return to home.

Every disadvantage has its advantage

Genghis9 Posted at 2017-9-14 21:00
Agree, I would like the option of a more quite UAV at times, but then other times that distinct noise can help ID your bird when seeing it may be iffy.  Also, I'd bet money that quitter props would like result in a change in flight capability.  Likely you'd loose some speed and climb rate but you might get better flight time duration.

Thats what I would be afraid of... I can live with the noise.  Don't reduce flight time, stability, reliability, power.... yeah... none of that....

Tmygun Posted at 2017-9-15 02:28
Not sure I want quieter props.  
While it sounds like an attractive idea, I worry about the lower noise level making the UAV a more attractive target for Angry Birds (couldn't resist).

That is an excellent thought, and while I have had birds come close I have had no problem yet.  However, I did not think of that point and I agree it is something to consider.
Yet, operating indoors would be different and nice if you had a quitter kit too.  I can see uses for both capabilities.

Cetacean Posted at 2017-9-15 01:36
Aloha Susan,

     Three (or 4) blades with smaller radius will make for quieter props.  Also having the shorter blades will help keep the props more out of the picture when the Phantom tilts forward.

All good points
Somehow I don't think the jig cost would be a factor for DJI, however, they could license this out too.  I'm sure there are plenty of existing companies that would love to get a piece of this market.  
At some point DJI should consider the accessory aspect to their market, they have got hundreds of thousands of these things out there now if not millions, so the accessory market has got to be busting to break out with things like this.

I'd up vote for a slightly quieter flight experience too.  

Genghis9 Posted at 2017-9-15 08:33
All good points
Somehow I don't think the jig cost would be a factor for DJI, however, they could license this out too.  I'm sure there are plenty of existing companies that would love to get a piece of this market.  
At some point DJI should consider the accessory aspect to their market, they have got hundreds of thousands of these things our there now if not millions, so the accessory market has got to be busting to break out with things like this.

Aloha Genghis,

     They already are using third party manufacturers.  But, the engineering has to be done by DJI.  The propguards for the P4 Pro were delayed due to the third party manufacturer getting up to speed.  

     The point is that there are ways to make the props quieter and numerous other things.  It just has to get on the DJI agenda.  That is why I hoped to inspire DJI Susan about the possibilities.  Maybe she could champion this idea.  She seems to like it.  Now she knows it is not that hard.

Aloha and Drone On!

Cetacean Posted at 2017-9-15 16:37
Aloha Genghis,

     They already are using third party manufacturers.  But, the engineering has to be done by DJI.  The propguards for the P4 Pro were delayed due to the third party manufacturer getting up to speed.  

All good points...as I noted, if DJI is forward thinking, I think they are, then maybe soon we'll see more energy put in to accessories that further enhance the experience and provide greater choice.

As of today I do not see any prop options for stealth. I’m looking for low noise props.

DJI Susan Posted at 2017-9-14 20:26
It's a cool idea. Hopefully the engineers will consider it in the future.

I hope so as well, The P4P is definitely much louder that the P3P and the Mavic combined in my opinion, especially that High pitch squeal when throttling up or it self correcting.

This thread repeats itself every 10 days or so. There are no quiet propellers, you may be able to get quieter propellers but at what sacrifice. There is no shortage of ideas of how to make quieter propellers, each idea has its champions, and each idea is shot to smithereens by other “experts”.

Enter “quieter propellers” in Google and you can spend hours arguing the cases. Before you do so it would be wise to understand terms like “hypothesis”, “assumption” or “axiom” and have a degree in “theoretical mathematics”.

DJI have actually got a very advanced propeller design on the Phantom, there are some very sound aerodynamic arguments for its triangular form with broad inner chord and tapered outer tip.

If you really want quiet, get old like me and turn your hearing aid down. That works not only with drones but also with children, dogs and nagging wives, to name just a few.

ALABAMA Posted at 2017-9-14 11:51
I like that noise.......especially after a disconnect and return to home.

The first time that this happened to me (Disconnected that is) I sh@# myself. I'd only had the thing a day and I thought I had lost it forever. I hit the RTH button, thinking nothing was happening and then that beautiful noise 60m above my head. Aah, it was such a special occasion, just like the Walt Disney film, The Incredible Journey when the two dogs and Siamese cat came home.  

NGF Posted at 2017-11-6 12:23
The first time that this happened to me (Disconnected that is) I sh@# myself. I'd only had the thing a day and I thought I had lost it forever. I hit the RTH button, thinking nothing was happening and then that beautiful noise 60m above my head. Aah, it was such a special occasion, just like the Walt Disney film, The Incredible Journey when the two dogs and Siamese cat came home.  

https://youtu.be/SOnkKrYuBHY?t=1h33m

FF to 1:33

NGF Posted at 2017-11-6 12:26
FF to 1:33

Ahaaaaa Yes, They don't make any like that one now days!  

Cetacean Posted at 2017-9-15 01:36
Aloha Susan,

     Three (or 4) blades with smaller radius will make for quieter props.  Also having the shorter blades will help keep the props more out of the picture when the Phantom tilts forward.

Hi Cetacean just on the length of props, it seems that with newer quieter props on the Mavic PP are longer than regular props these of course are having the negative effect of coming more into Camera view, so not to sure we will see shorter props with less noise surely shorter props would have to work harder causing more noise.

hallmark007 Posted at 2017-11-7 08:24
Hi Cetacean just on the length of props, it seems that with newer quieter props on the Mavic PP are longer than regular props these of course are having the negative effect of coming more into Camera view, so not to sure we will see shorter props with less noise surely shorter props would have to work harder causing more noise.

Aloha 007,

     Yes, the redesign of the prop itself will quiet down the prop, but shortening the blade has a quieting effect within limits.  For full size helicopters, they have slowed down the rpm by adding more blades when they made the blades shorter and thus made it quieter.  That was what I was aiming at.  

     The notoriously loud Huey with two blades of Viet Nam War fame has had its props redesigned and now have three blades that rotate in a much smaller diameter.  They fly as a team with the Apache now.  

     My goal is to have DJI redesign the props so that the prop diameter is shorter with three or four blades to keep the rpm down and make it quieter.  This will keep the blades out of the field of view more.  But there will be some engineering required to manage the trade-offs.

      So how is the CS 7.85 doing?  Which did you get?  Do you have to use the large battery with it?  Is there a smaller battery you can use so it is lighter in the Remote Controller?

Aloha and Drone On!

Cetacean Posted at 2017-11-8 02:14
Aloha 007,

     Yes, the redesign of the prop itself will quiet down the prop, but shortening the blade has a quieting effect within limits.  For full size helicopters, they have slowed down the rpm by adding more blades when they made the blades shorter and thus made it quieter.  That was what I was aiming at.  

Hi Cetacean , I bow to your superior knowledge on this subject, it certainly would be a great improvement if we could see the props removed from Camera view and less noise would be a nice bonus,

CS yes I just took delivery of the 7.85 yesterday I’ve had the 5.5 for a couple of weeks and I can say it has for me worked great, yes battery is heavy comes in at 750g plenty of power up to 4/5 hours and altogether the unit feels very solid, video transmission is noticeably improved and you can use screen in total sunlight.
7.85 is almost exactly the same slight difference in where you insert sd cards and higher screen resolution it comes in at an extra €100 but in my opinion it’s value is much greater you get a much bigger screen 2 batteries so certainly for phantom it’s a no brainer, and because of its size there is no noticeable difference in the weight.
It’s great being able to watch what you’ve just shot using the sd card slot, it also has a beta version of the dji pilot app for those concerned about data privacy.
Although there are many who feel it’s to expensive , when you see what you get for your money and compare to similar items I think it’s pretty good value but would seriously recommend getting 7.85 screen.
Good luck.

hallmark007 Posted at 2017-11-8 03:17
Hi Cetacean , I bow to your superior knowledge on this subject, it certainly would be a great improvement if we could see the props removed from Camera view and less noise would be a nice bonus,

CS yes I just took delivery of the 7.85 yesterday I’ve had the 5.5 for a couple of weeks and I can say it has for me worked great, yes battery is heavy comes in at 750g plenty of power up to 4/5 hours and altogether the unit feels very solid, video transmission is noticeably improved and you can use screen in total sunlight.

Aloha 007,

     Yes, I would not get the 5.5, way too small for my old eyes.  Even the 7.85 is not big enough but I may still get one anyway.  

     Keep us posted on how it goes!

Aloha and Drone On!

Correct me if i'm wrong - it seems they have made new quieter blades for the Mavik? Hopefully coming for the P4P soon!...

Please correct me if I'm wrong - didn't they just release quiet blades for the Mavik? Hopefully coming soon for P4P!...

Yea i keep looking for it...   It would be a simple tip design change to add a offset at the tip to break the centrifugal air flow off the tip causing a turbulence vortex behind the tip...  That has been incorporated in many new helos lately to quit the noise of the props and easily could be added to the molds when making the stock props ..  It even has the added benefit of increasing lift by getting rid of the vortex at the blade tip   

This would be the Simple Fix and some blade manufacture should make them.. they would sale like hot cakes...

Genghis9 Posted at 2017-9-14 21:00
Agree, I would like the option of a more quite UAV at times, but then other times that distinct noise can help ID your bird when seeing it may be iffy.  Also, I'd bet money that quitter props would likely result in a change in flight capability.  Likely you'd loose some speed and climb rate but you might get better flight time duration.

Use of tip off sets actually increase lift and top speeds on Helo's

Quantummist Posted at 2018-1-10 11:22
Use of tip off sets actually increase lift and top speeds on Helo's

Yes that design would likely reduce induced drag from the prop which may reduce the noise factor.  As you likely know, this design is very much like the new mavic props.  I assume the articulated tip is slightly uplifted too?  
What is not evident, I don't know what performance factors it may effect by doing so.  If negligible, then maybe a third party manufacturer or DJI will come around to this design.  There is something to be said for having sound as much as not having it.

Fantastic idea, great. Let's wait and see

I put the new quieter props on my Mavic, it did make it a little bit quieter. The biggest thing I noticed was that the pitch of the sound changed, my dogs went nuts when I started up the Mavic, with the new props, they ignore me.

NGF Posted at 2017-11-6 12:23
The first time that this happened to me (Disconnected that is) I sh@# myself. I'd only had the thing a day and I thought I had lost it forever. I hit the RTH button, thinking nothing was happening and then that beautiful noise 60m above my head. Aah, it was such a special occasion, just like the Walt Disney film, The Incredible Journey when the two dogs and Siamese cat came home.  

https://youtu.be/SOnkKrYuBHY?t=1h33m

WOW     a forum and a movie           

Cetacean Posted at 2017-9-15 01:36
Aloha Susan,

     Three (or 4) blades with smaller radius will make for quieter props.  Also having the shorter blades will help keep the props more out of the picture when the Phantom tilts forward.

Aloha Cetacean,

shorter blades means more spin and more power from the engines.
Assuming the engines can deliver this extra power (which I doubt) their lifespan will be decreased because will be forced to work above the rotation range were designed.
I think DJI should try to develop propellers for high altitude flights. Those were available on P2 but then disappeared on following models. I flown P4P+ in areas between 3500 and 5100 m and stability and manoeuvrability of the AC is drastically reduced even without wind. They claim it can fly up to 6000m. Perhaps yes, but it depends on having a zero wind conditions and this is an ideal case. Having flown it at 5000m I found the real limitations and are below what the manufacturer claims

15matjan Posted at 2018-1-11 00:19
Aloha Cetacean,

shorter blades means more spin and more power from the engines.

Aloha Matjan ,

     There are many variables in prop design that can arrive at the same destination of power consumption at the motor level by different paths.  Two blade systems, three blade systems and four blade systems can each be designed with variables that arrive at the same power consumption.  Tip modifications can be applied to each of the designs for specific purposes.  The three configurations will each have different benefits and drawbacks.  Sound levels and appearance in videos are drawbacks and benefits that are interesting to our fun use of Phantoms.  It is all engineering and DJI has the resources to look at these drawbacks and benefits when they put it on their agenda.

    DJI has amazing resources available to them now with the amazing sales they have achieved.  If I was younger, I would probably try to get more involved with engineering like this.  To me this is almost as much fun as flying our Phantoms.

     As for the high-altitude propellers, DJI does still make them.  The Inspire 2 uses them.  Here is the link;

https://store.dji.com/product/in ... s-for-high-altitude

Sorry, but I have not found any for the Phantoms.

Aloha and Drone On!

Cetacean Posted at 2017-9-15 01:36
Aloha Susan,

     Three (or 4) blades with smaller radius will make for quieter props.  Also having the shorter blades will help keep the props more out of the picture when the Phantom tilts forward.

quadcopters are much more stable than tris, that's why they're preferred for most drones. (octacopters are very, very stable, but man are they pricey and bulky!)

Cetacean Posted at 2018-1-11 03:34
Aloha Matjan ,

     There are many variables in prop design that can arrive at the same destination of power consumption at the motor level by different paths.  Two blade systems, three blade systems and four blade systems can each be designed with variables that arrive at the same power consumption.  Tip modifications can be applied to each of the designs for specific purposes.  The three configurations will each have different benefits and drawbacks.  Sound levels and appearance in videos are drawbacks and benefits that are interesting to our fun use of Phantoms.  It is all engineering and DJI has the resources to look at these drawbacks and benefits when they put it on their agenda.

Aloha Cetacean,

definitely there are no other propellers for P4 except for the standard ones.
Being at the upper level of non-professional drone, I assume there aren't enough customers living in high altitude zones to determine DJI a different propeller design and option as necessary.

15matjan Posted at 2018-1-12 07:07
Aloha Cetacean,

definitely there are no other propellers for P4 except for the standard ones.

Aloha Matjan ,

     Bummer!  Oh well.  But, we can dream of the P5!

Aloha and Drone On!