Question

[mavic3usa]

Unfortunately this was my biggest issue with the Mini 2 and why I switched to the Mini 3. It was *always* too windy to fly where I live. Never any fun. It was so wind that I would step outside on a completely calm day, travel 5 minutes to my site, launch my drone and the wind would pick up right about the same times as "Your homepoint has been updated." My drone was buffeting around, I would have to come right back down and land and try to wait for the winds to calm but it didn't within 15 minute so i went home and when I got out of my car, there was no wind. It's as if the flag flying out front was completely laying on the flag pole. But, I'm done for the day...fool me once.

 

[Meta4]

Unfortunately this was my biggest issue with the Mini 2 and why I switched to the Mini 3.

Specs for the Mini 3's performance are the same as the Mini 2, so you wouldn't have seen any advantage regarding wind.

 

[LoudThunder]

If you can still stand up in the wind, you can fly your drone, just don't expect the drone to ever get back to the home point...

 

[mavic3usa]

Specs for the Mini 3's performance are the same as the Mini 2, so you wouldn't have seen any advantage regarding wind.

Perhaps but they sure don't perform the same way. I still have both so I will put them up in the air together the next time. Hopefully I'm not thinking Mini 1 which had the problem even worse. I do remember feeling better with Mini 2 but it was only ok and much better with Mini 3. That's my recollection.

 

[Meta4]

Perhaps but they sure don't perform the same way. I still have both so I will put them up in the air together the next time.

Their specs indicate that they have the same speed potential.
Mini 2 & 3
Max Speed (near sea level, no wind)
16 m/s (S Mode)
10 m/s (N Mode)
6 m/s (C Mode)

Hopefully I'm not thinking Mini 1 which had the problem even worse. I do remember feeling better with Mini 2 but it only because ok with Mini 3. That's my recollection.

The original DJI Mini was much less capable in wind because it was significantly slower.

Original Mini
13 m/s (S Mode)
8 m/s (N Mode)
4 m/s (C Mode)

 

[Droning on and on...]

I believe the confusion stems from available thrust, which impacts wind resistance, vs. maximum speed which is controlled by the FC. Unless I'm mistaken, the days of setting groundspeed records flying downwind with DJI drones is long past, as top speed is regulated by the FC based on GPS ground speed.

So it's entirely possible to have a drone with top speed limited based on non-technical factors (like product family), while having better wind resistance because of more powerful motors.

This is why the mini 2 is only 2m/s faster than the mini 1 in Normal, but has much much better wind resistance.

Ironically, the wind resistance spec is a better performance comparison between DJI drones than the max speed. In the former case, the aircraft is using up almost all available power to make ground progress flying upwind; at max speed it probably isn't – under most mildly breezy or calm circumstances.

As for how DJI measures wind resistance, they don't tell us. But they're good engineers. I expect they have a consistent, repeatable test environment for this.

I disagree with @Meta4... Top speed specs are what are relatively meaningless as a performance metric. All they tell you is what speed DJI has configured as a limit. The fact that max speed is different for C, N, S modes makes this case. All you're gaining insight into is what DJI has set the max speed to.

 

[LoudThunder]

I think this discussion is going nowhere and all that can be said is "we need to agree to disagree..."

Wind is wind and a breeze is a breeze. How a drone responds to the movement of the air is all a moot point (assuming the movement is below the maximum values that are established in anyplace other than the "great outdoors…") and the values were probably established in a wind tunnel with a constant, non-varying velocity movement of air…

When you are outside, not only is the breeze or wind gusting at times, it also changes direction. And if you are flying around obstacles (trees, building, cars, playground sets, etc… the changes caused by the change in direction is unpredictable.

So you can debate the issues all day and you may still fly your drone into that tree because as you flew downwind of the tree, the tree caused a vortex that "sucked" your little drone right inio it…

Isn't it a much better use of your time to go fly than defending points of contention that are all debatable and contentious…

 

[Meta4]

Ironically, the wind resistance spec is a better performance comparison between DJI drones than the max speed. In the former case, the aircraft is using up almost all available power to make ground progress flying upwind; at max speed it probably isn't – under most mildly breezy or calm circumstances.

DJI's "wind resistance is not a gauge of anything that's at all meaningful.
Whether the drone is flying at maximum speed in still air or against a strong wind, or even being blown backwards, its airspeed is the same.
If you want to know whether your drone can make it home against a headwind, the only metric that counts is the maximum speed that the drone is capable of.

As for how DJI measures wind resistance, they don't tell us. But they're good engineers. I expect they have a consistent, repeatable test environment for this.

They also don't define their "wind resistance" and I've never found anyone who could explain what it actually means.
My assessment of it is that it's a nonsense number (or a range of numbers) that cannot be used to tell much at all.

I disagree with @Meta4... Top speed specs are what are relatively meaningless as a performance metric. All they tell you is what speed DJI has configured as a limit. The fact that max speed is different for C, N, S modes makes this case. All you're gaining insight into is what DJI has set the max speed to.

DJI sets the same tilt angle limits for all the Mavics and Minis.
At any speed, the drone only uses a part of the motor's thrust for forward propulsion with most going to counteract gravity.
Changing the tilt angle changes the proportion of thrust that's directed to forward motion.

But since you don't accept any of this, how about explaining what you think the mystery "wind resistance" actually is or how a pilot can use this information?

 

[Sam36401]

I think this discussion is going nowhere and all that can be said is "we need to agree to disagree..."

I could NOT agree more.

 

[netfolks2000]

Didn't read all responses yet... didn't see the reminder that wind speed can vary greatly by altitude. Can be much more wind speed up higher.

 

[Sam36401]

Didn't read all responses yet... didn't see the reminder that wind speed can vary greatly by altitude. Can be much more wind speed up higher.

Post #3

 

[Droning on and on...]

DJI sets the same tilt angle limits for all the Mavics and Minis.

Max ground speed –what is spec'd – is governed by the Flight Controller in DJI drones, not the max tilt angles. This is why under moderate winds the drone maxes out at the same ground speed regardless of course relative to wind direction.

Max tilt will control max airspeed, which DJI does not specify, and which is not measured or detected in any way by the system. There is no pitot tube on any DJI drone.

At any fixed speed as indicated in the display – which is proportional to stick position – pitch angle will continuously vary in windy conditions as heading changes. The FC is maintaining ground speed. There's nothing special about the spec'd max speed in this regard.

At any speed, the drone only uses a part of the motor's thrust for forward propulsion with most going to counteract gravity.
Changing the tilt angle changes the proportion of thrust that's directed to forward motion.

Yup. That's how they fly.

But since you don't accept any of this, how about explaining what you think the mystery "wind resistance" actually is or how a pilot can use this information?

"Any of this"? Not following.

I don't accept your assertion that wind resistance specs are meaningless, and I've thoroughly explained why. Add to that I don't accept your explanation for what the max speed spec represents either, as explained above.

 

[Meta4]

Max tilt will control max airspeed, which DJI does not specify, and which is not measured or detected in any way by the system. There is no pitot tube on any DJI drone.

DJI do specify Max Airspeed.
You just don't understand that Max Speed in still air = Max Airspeed.
Not understanding that basic concept explains your confusion.

I don't accept your assertion that wind resistance specs are meaningless, and I've thoroughly explained why.

On the contrary.
You haven't explained anything at all about what DJI's Max Wind Resistance is or how it is relevant to anyone flying their drones.
I asked earlier, but no explanation has been forthcoming.

 

[Droning on and on...]

DJI do specify Max Airspeed.
You just don't understand that Max Speed in still air = Max Airspeed.

Incorrect.

DJI drones can fly at their spec'd max ground speed into a moderate wind. When they do, they are flying at a greater airspeed than the specified max ground speed.

Your are incorrect that max ground speed in still air is the drone's max airspeed.

Not understanding that basic concept explains your confusion.

You seem to lack an understanding of the Flight Controller and what it's doing, to wit your assertion above relating max ground speed to max air speed under windless conditions.

Think about this: In N mode, is the drone capable of flying at a higher windspeed than the Normal Mode spec for "max speed"? What do you claim happens in N mode when flying full stick into an 8mph wind? Will the drone fly at max ground speed over the ground, or max-8?

 

[Meta4]

Incorrect.

DJI drones can fly at their spec'd max ground speed into a moderate wind. When they do, they are flying at a greater airspeed than the specified max ground speed.

Your are incorrect that max ground speed in still air is the drone's max airspeed.



You seem to lack an understanding of the Flight Controller and what it's doing, to wit your assertion above relating max ground speed to max air speed under windless conditions.

Think about this: In N mode, is the drone capable of flying at a higher windspeed than the Normal Mode spec for "max speed"? What do you claim happens in N mode when flying full stick into an 8mph wind? Will the drone fly at max ground speed over the ground, or max-8?

Obviously at full stick, the drone flies at full airspeed, which is the same as full speed in still air.
If the air mass is moving at 8mph in the opposite direction, to the drone's groundspeed is max still airspeed - 8mph.

I can't see any point in dragging this conversation out with someone who refuses to understand the most basic concepts of drone flying.
Or someone who can't explain what DJI's Max Wind Resistance is, but insists that it's useful information.

 

[Droning on and on...]

Obviously at full stick, the drone flies at full airspeed, which is the same as full speed in still air.
If the air mass is moving at 8mph in the opposite direction, to the drone's groundspeed is max still airspeed - 8mph.

Ahh, that's where your confusion is.

In an 8mph headwind a DJI drone in N mode will still fly at specified max ground speed. And at max+8 airspeed.

Go out and try it.

I can't see any point in dragging this conversation out with someone who refuses to understand the most basic concepts of drone flying.
Or someone who can't explain what DJI's Max Wind Resistance is, but insists that it's useful information.

There's no need to be insulting.

You're simply mistaken. There's nothing wrong with that.

Rather than insult, how about you educate? I certainly am open to being wrong, and if I am, I'd like to know the correct information. So please explain this to me: If the drone has no way to measure airspeed, or know what the windspeed is over the ground, how does it know to fly 8mph slower over the ground? Obviously, being in N mode there's plenty of extra power, so the speed is not being limited by capability.

 

[@Rip]

DJI's Max Wind Resistance

So I am interested in this also. Do I think it "matters much" No. But Someone should actually query DJI for the information. Their specs say one thing, and "some" say it is irrelevant, or "not defined".. I look at it as a guideline, at least. Not an imperial rule.
Does it affect my flights? Not really. I fly when I need and want to. It is Always windy here. And I am almost always getting "warnings". But the drone, so far has been true to the mission.
Sometimes it is obviously too windy. OK. Gusts and wind are different and wind (and gusts) are not linear they are dynamic.
I agree with @Meta4 as to the "specs", but I also agree with others who ask the questions. There are no bad questions, only bad answers. Let's not resign ouselves to having bad data and information from our manufacturer, lets hold them to the facts and find out what their litmus test is and why.

 

[mobilehomer]

Two things combine to set speed over ground. Max tilt and gps. The drone will fly at max gps speed until max tilt is reached. Then it cannot go any faster speed over ground. Could it be that Max Wind Resistance is the point where the drone can no longer make headway speed over ground at max tilt?

 

[Droning on and on...]

Two things combine to set speed over ground. Max tilt and gps. The drone will fly at max gps speed until max tilt is reached. Then it cannot go any faster speed over ground. Could it be that Max Wind Resistance is the point where the drone can no longer make headway speed over ground at max tilt?

Bingo.

Ground speed (via GPS) is the only metric available, and this is what the Flight Controller tries to maintain based on stick position. The max tilt configured will result in a higher airspeed than the specified max speed of the drone in still air, margin deliberately configured to provide some wind resistance even at full throttle in S mode.

Even though I apparently don't understand the most basic concepts of drone flying, I was hacking these parameters years ago on the original Mavic Pro, playing with max speed in Sport and max tilt. But what do I know? Not even the most basic concepts of drone flying!!!

 

[Meta4]

So I am interested in this also. Do I think it "matters much" No. But Someone should actually query DJI for the information.
... Let's not resign ouselves to having bad data and information from our manufacturer, lets hold them to the facts and find out what their litmus test is and why.

Unfortunately DJI aren't very good at addressing questions from their customers.
Their support people cannot be relied on for detailed technical information.