Phantom 4 - Dirty Thoughts

WWK888 · Mar 21, 2016

snowghost said:
I have over 130 flights on my P3, and she is fully intact--no cracks. But I still worry about it. The bummer about upgrading is all the equipment invested in the P3.

Are most of you guys keeping both?

I am keeping both. I had originally planned to sell my P3P and had several friends who were willing to buy it. I kinda like the idea of having a backup and if this battery flight time issue is not sorted out I will use the P3P for longer flights.

Dirty Bird · Mar 21, 2016

I'm keeping them all!

snowghost said:
I have over 130 flights on my P3, and she is fully intact--no cracks. But I still worry about it. The bummer about upgrading is all the equipment invested in the P3.

Are most of you guys keeping both?

Davphys · Mar 21, 2016

Anyone figure this out yet regarding collision avoidance?- Does it automatically engage in smart RTH? Even if I am flying in Sport mode? Or even if it is turned off in the app?

Kman · Mar 21, 2016

snowghost said:
I have over 130 flights on my P3, and she is fully intact--no cracks. But I still worry about it. The bummer about upgrading is all the equipment invested in the P3.

Are most of you guys keeping both?

I'll probably be returning my P4.

The range is a huge problem for me. I have Version A of the P3P and I love how far I can fly.

John Locke · Mar 21, 2016

Davphys said:
It is a little more complicated than that. A lot of the increase in velocity is due to an increased allowable angle, not directly increased thrust of the motors, thus it does not take a battery hit as high as would be expected if it was purely an output increase.

The p4 has an 18% increase in vertical speed. The motors are definitely more powerful and consume more power. With a greater angle of attack it takes more power to maintain elevation, resulting in faster horizontal speed.

Davphys · Mar 21, 2016

They do, but again some of that is because of aerodynamics, etc. I'm not saying the motors don't use more power. I am saying though that the speed in sport mode is not completely caused by motor output. Specifically the 44mph horizontal speed.

John Locke said:
The p4 has an 18% increase in vertical speed. The motors are definitely more powerful and consume more power.

John Locke · Mar 21, 2016

Davphys said:
They do, but again some of that is because of aerodynamics, etc. I'm not saying the motors don't use more power. I am saying though that the speed in sport mode is not completely caused by motor output. Specifically the 44mph horizontal speed.

To increase vertical speed 18%, with a craft that weighs 100gms more than P3, the motor power output has got to be significantly increased, I'm thinking 30% more than P3 (pure guess).That kind of increase in power consumption would explain the battery life disappointment.

sar104 · Mar 21, 2016

Davphys said:
They do, but again some of that is because of aerodynamics, etc. I'm not saying the motors don't use more power. I am saying though that the speed in sport mode is not completely caused by motor output. Specifically the 44mph horizontal speed.

Unless you are suggesting that the aircraft body produces significant aerodynamic lift, then the increase in horizontal speed has to use more thrust, since the otherwise reduced (due to attack angle) vertical component is entirely responsible for lift.

Davphys · Mar 21, 2016

There are even the intro videos to the P4 unveiling where the engineer specifically states they don't drain the batteries as much as expected specifically because they allow for a greater than 40 degree tilt to get the speed. Feel free to email the engineer [email protected] if you want clarification.

sar104 · Mar 21, 2016

Davphys said:
There are even the intro videos to the P4 unveiling where the engineer specifically states they don't drain the batteries as much as expected specifically because they allow for a greater than 40 degree tilt to get the speed.

In the absence of aerodynamic lift, the force vectors still have to add up. For steady horizontal flight the vertical component must equal the weight, and the horizontal component must equal the aerodynamic drag (which goes with the square of velocity). And in propulsion, the force is the rate of change of momentum of the working fluid - air in this case - and work is approximately the product of the force and relative velocity. There is nothing for free here. So you reject DJI's claims of flight duration, but believe their engineer when his explanation violates basic physics?

Dirty Bird · Mar 21, 2016

Just conducted the following battery test:

P-mode
Collision Avoidance DISABLED
Recording 4K video during flight
Straight hover to 0% battery
Minimal control input
45 degrees, slight breeze

24:35 (will add video when YouTube finishes)

NormanNormal · Mar 21, 2016

Dirty Bird said:
Just conducted the following battery test:

P-mode
Collision Avoidance DISABLED
Recording 4K video during flight
Straight hover to 0% battery
Minimal control input
45 degrees, slight breeze

24:35 (will add video when YouTube finishes)

Wow that pretty much nukes DJI's 28 min claim right there. Can't even make it doing a hover to 0 percent.

bighi · Mar 21, 2016

Now here is a question. Just how do we go about getting ahold of the super phantoms that DJI people fly? I'd be willing to pay extra for those wonder birds. Phantom 4s with phantom 3 FPV capability and 28 minute flight times. Where do I send the money for that phantom 4?

Dirty Bird · Mar 22, 2016

Here is the real-time Phantom 4 Ultimate Battery Test video - 24:35

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Fallguy · Mar 22, 2016

bighi said:
Now here is a question. Just how do we go about getting ahold of the super phantoms that DJI people fly? I'd be willing to pay extra for those wonder birds. Phantom 4s with phantom 3 FPV capability and 28 minute flight times. Where do I send the money for that phantom 4?

Thats how long it takes for it to fall off the top of Mt. Fuji .

Dirty Bird · Mar 22, 2016

Mt. Everest. Mt. Fuji is in Japan & it's less than half as tall!

Fallguy said:
Thats how long it takes for it to fall off the top of Mt. Fuji .

Fallguy · Mar 22, 2016

Probably still needed a Sherpa to carry it up there.

GadgetGuy · Mar 22, 2016

snowghost said:
I have over 130 flights on my P3, and she is fully intact--no cracks. But I still worry about it. The bummer about upgrading is all the equipment invested in the P3.

Are most of you guys keeping both?

One would be foolish not to keep both, as the P3P output is, IMHO, still better than the P4. Every video shot with the P4 so far has props in the frame and suffers from random jerkiness in the video. That additional speed does not help the vieo!

GadgetGuy · Mar 22, 2016

Davphys said:
It is a little more complicated than that. A lot of the increase in velocity is due to an increased allowable angle, not directly increased thrust of the motors, thus it does not take a battery hit as high as would be expected if it was purely an output increase.

That increased allowable angle also puts the props in the frame, if you intend to include the horizon in your video.

GadgetGuy · Mar 22, 2016

WWK888 said:
I am keeping both. I had originally planned to sell my P3P and had several friends who were willing to buy it. I kinda like the idea of having a backup and if this battery flight time issue is not sorted out I will use the P3P for longer flights.

Exactly!