Question

[Droning on and on...]

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.

Could you share with me the information that convinces you it's bad data or information from DJI?

If you're relying on @Meta4's statements, that's exactly what I'm challenging. A claim is insufficient. I need some evidence. I'm not willing to so casually assume without any basis that DJI is BS'ing us.

That said, DJI doesn't tell us how they measure or calculate it, or what it specifically means in terms of how the drone will perform, so it has limited value. What I'm disputing is that it has NO value. Assuming it is not made up BS but actually something measured or derived from other performance factors, it's useful for comparison between DJI models.

 

[@Rip]

Could you share with me the information that convinces you it's bad data or information from DJI?

If you're relying on @Metal's opinion, that's exactly what I'm challenging. A claim is insufficient. I need some evidence. I'm not willing to so casually assume without any basis that DJI is BS'ing us.

That said, DJI doesn't tell us how they measure or calculate it, or what it specifically means in terms of how the drone will perform, so it has limited value. What I'm disputing is that it has NO value. Assuming it is not made up BS but actually something measured or derived from other performance factors, it's useful for comparison between DJI models.

Is this a private thread?

 

[Meta4]

Could it be that Max Wind Resistance is the point where the drone can no longer make headway speed over ground at max tilt?

That's easy to test by looking at the specs.
A Mavic 3 has a max speed in still air of 15 metres/sec (N Mode) and 21 M/s in Sport Mode.
DJI suggest it has a Max Wind Resistance of 12 M/s.
Can a Mavic 3 at Max Tilt make headway flying against a headwind of 12 m/s or more?
Obviously it can.

Try again with the numbers for an Inspire 3
Max speed = 26 m/s, yet the Max Wind Resistance claimed is only 14 m/s.

What DJI means by Max Wind Resistance is a mystery.
If only the person claiming that I'm wrong would share his insight and explain it, perhaps we'd understand.

He's confused by DJI changing firmware back when the underpowered DJI mini was being blown backwards by moderate breezes in N mode.
The change allowed the drone to use a tilt angle up to the max for Sport Mode if it was being blown away, even when the drone was in N mode.

 

[@Rip]

Could you share with me the information that convinces you it's bad data or information from DJI?

If you're relying on @Metal's opinion, that's exactly what I'm challenging. A claim is insufficient. I need some evidence. I'm not willing to so casually assume without any basis that DJI is BS'ing us.

That said, DJI doesn't tell us how they measure or calculate it, or what it specifically means in terms of how the drone will perform, so it has limited value. What I'm disputing is that it has NO value. Assuming it is not made up BS but actually something measured or derived from other performance factors, it's useful for comparison between DJI models.

 

[@Rip]

That's easy to test by looking at the specs.

These are the "specs" that are in question yes?

 

[Meta4]

These are the "specs" that are in question yes?

Most of DJI's specs are accurate and easily understood.
It's their Max Wind Resistance that is an unknown quantity.
DJI have never defined it, I've not been able to work out what it is or how it is of any use to drone flyers.
And I've not found anyone else who can explain it.

It's hard to make any sense of it when you compare it to the performance specs for different models.
I's certainly not an indication of the max wind you can fly in, as many have assumed.

 

[@Rip]

Max Wind Resistance that is an unknown quantity

I take that as a yes.

DJI doesn't tell us how they measure or calculate it,

That is the whole point. If no one else will do it I will. Ask DJI for a specific explanation of Max Wind Resistance and how they come to their declarations in the specs. At least there will be a response, hopefully. If not then we can speculate and argue the validity and/or meaning of the spec.
BTW: I was on DJI support site looking for this specifically, and there is no mention or evidence of any question relating to this at all.

I suppose it is OK to say "it is meaningless" or "invalid" but I haven't seen anyone who has actually asked the question. I am not convinced.

I respect everyones opinion, but to claim an opinion as a fact is a stretch (without definitive evidence).

 

[@Rip]

Could you share with me the information that convinces you it's bad data or information from DJI?

I am not convinced. That is a hard sell for me. I didn't want to get into this argument. But I am here... and I will post my results, if any.

 

[@Rip]

And I've not found anyone else who can explain it.

DJI can. But will they?

 

[Droning on and on...]

So rather than keep arguing, I went down to my regular flying location at Seacliff State Beach and ran a test using my Mini3P.

Video starts with a shot of the flags at the entrance booth. Using observation and the Beaufort Scale, this is about a 10-12mph wind. Further, it was gusty, varying from 0-12mph constantly.

Then, I do a full stick flight upwind out to sea, and back with the wind at the drone's back. After that I did a run crosswind in both directions.

In all cases the speed was 21.5±1mph. This means that on the way out it was doing about ~30mph airspeed, ~10mph in the air on the way back.

Exactly as I said. See for yourself:

I repeated the test in Sport mode, but didn't record it. The Mini3P appears to have about 5mph of headroom above Sport max speed, as it topped out at 30mph upwind, 5mph short of Sport max speed. At 30 flying upwind in a 10mph breeze the Mini3P is capable of sustaining 40mph in the air. However this speed is unavailable in still air because the Flight Controller limits the speed to 35mph.

Again, exactly as I said above.

 

[Droning on and on...]

DJI can. But will they?

Probably not.

There are specs galore for all manner of products that are ambiguous, poorly explained and of limited value. Wind "resistance" is among them. The only disagreement I had originally with @Meta4 was his assertion that it's meaningless.

I assume there's some real measurement or logically derived value from other performance measurements that DJI engineers have developed.

I find DJI Support and Marketing to often be incompetent and cringe-worthy, but I have a lot of respect for the engineers.

 

[@Rip]

So rather than keep arguing, I went down to my regular flying location at Seacliff State Beach and ran a test using my Mini3P.

Video starts with a shot of the flags at the entrance booth. Using observation and the Beaufort Scale, this is about a 10-12mph wind. Further, it was gusty, varying from 0-12mph constantly.

Then, I do a full stick flight upwind out to sea, and back with the wind at the drone's back. After that I did a run crosswind in both directions.

In all cases the speed was 21.5±1mph. This means that on the way out it was doing about ~30mph airspeed, ~10mph in the air on the way back.

Exactly as I said. See for yourself:

I repeated the test in Sport mode, but didn't record it. The Mini3P appears to have about 5mph of headroom above Sport max speed, as it topped out at 30mph upwind, 5mph short of Sport max speed. At 30 flying upwind in a 10mph breeze the Mini3P is capable of sustaining 40mph in the air. However this speed is unavailable in still air because the Flight Controller limits the speed to 35mph.

Again,

Probably not.

There are specs galore for all manner of products that are ambiguous, poorly explained and of limited value. Wind "resistance" is among them. The only disagreement I had originally with @Meta4 was his assertion that it's meaningless.

I assume there's some real measurement or logically derived value from other performance measurements that DJI engineers have developed.

I find DJI Support and Marketing to often be incompetent and cringe-worthy, but I have a lot of respect for the engineers.

OK I get that. But as I stated... I consider it a "Guideline" that's all. i will still ask the question. But (and thank you for your recent test) I haven't figured out how to ascertain the specifics on this matter with the equipment and sensors available. I am still working on it after similar "challenges" from @Meta4 . He is experienced and knowledgeable.

That is why I endeavor to test, measure and compare. It is not like it is the end of the world.. It is just interesting and intriguing.
Somehow it is worth investigating. Possibly to our peril. Possibly not.
It is all about learning.

 

[Droning on and on...]

I'd like to know too what specifically they mean by it – how they determine this spec. On that there's no disagreement.

 

[Meta4]

I repeated the test in Sport mode, but didn't record it. The Mini3P appears to have about 5mph of headroom above Sport max speed, as it topped out at 30mph upwind, 5mph short of Sport max speed. At 30 flying upwind in a 10mph breeze the Mini3P is capable of sustaining 40mph in the air. However this speed is unavailable in still air because the Flight Controller limits the speed to 35mph.

There is no data to show actual wind speed, just an estimate.
Without flight data showing pitch, roll and yaw data it's hard to make much of this.

The only disagreement I had originally with @Meta4 was his assertion that it's meaningless.

But pages later, you still haven't explained what what it actually is or how it can be used to flyers.

 

[Droning on and on...]

I am not convinced. That is a hard sell for me. I didn't want to get into this argument. But I am here... and I will post my results, if any.

Looking forward to it. First though, what are you testing? Since DJI hasn't defined what "wind resistance" means, you need to come up with a definition.

The two obvious ones are max wind speed and still fly at specified max Sport ground speed, or max wind speed with drone able to fly at some unspecified minimum ground speed (N or S). I.e. "no slower than".

I think my testing earlier today rules out the former for the Mini3P. Since the Mini3P in Sport tops out at 40mph airspeed, and DJI specs max wind resistance at 24mph, we can deduce that "max wind speed resistance" at least in the case of the Mini3P means able to make a ground speed of 40-24=16mph in a 24mph headwind.

To test this you have to fly into wind blowing strong enough to keep you from achieving max ground speed in Sport. Only then will the aircraft fly at max tilt.

 

[Droning on and on...]

There is no data to show actual wind speed, just an estimate.

So? Unnecessary. There was wind, enough to make the flags stand out. are you really going make an issue out of not using an anemometer?

The necessary condition is there was significant wind. If the Mini3P operated the way you say then it simply would never have made it to 22mph, and further the speed would have been varying all over the place due to gusts.

Please explain the constant speed, at max N mode spec, flying upwind and downwind.

Without flight data showing pitch, roll and yaw data it's hard to make much of this.

Also Unnecessary. The only data necessary was ground speed flying in windy conditions to verify your claim or mine as to how wind would affect it. You said,

If the air mass is moving at 8mph in the opposite direction, to the drone's groundspeed is max still airspeed - 8mph.

This was shown empirically to be wrong. As it was based on your understanding of how the drone operates, something's incorrect there too.

I said it would fly at a faster airspeed upwind, slower downwind, and maintain constant ground speed. This is what happened.

some of your claims here, simply put, are wrong.

 

[Meta4]

Please explain the constant speed, at max N mode spec, flying upwind and downwind.

Sure ... when can I see the pitch. roll; and yaw data?

Also Unnecessary. The only data necessary was ground speed flying in windy conditions to verify your claim or mine as to how wind would affect it. You said,

Of course.
There's no need to see what the drone is actually doing (unless you don't want that to be known).

I said it would fly at a faster airspeed upwind, slower downwind, and maintain constant ground speed. This is what happened.
some of your claims here, simply put, are wrong.

And if we accept what you're saying, wind has no effect and drones can fly faster than the ir specced max speed.
Like I said ... there's no point continuing conversation with you.

 

[lookout]

The mini 1 had a problem towards the depletion of the battery; not making it back home. Some improvement came with the mini 2 and change in battery. Something to encourage having a little tailwind on the way home. But it may not quite work that way with a gps equipped model.

 

[LoudThunder]

Au Contraire Mon Ami… The Mini 2 can and has flown over 100 MPH and here is the YouTube Video to prove it… I'm not recommending it but it is to show it can be and has been done… In fact, under these conditions, it probably was flying backwards at 75 MPH while it was going full speed forward… That's what happens when the headwind is strong enough… And if you want to try this at home, make sure your Flyaway coverage is current…

 

[Droning on and on...]

And if we accept what you're saying, wind has no effect and drones can fly faster than the ir specced max speed.

I demonstrated it. Are you calling me a liar?

Or are you resting your criticism on not believing your own eyes for that flag standing out? That's lame in the extreme.

You are being unreasonable. However, I'll post the flight logs so you can see for yourself the constant higher motor RPM, the greater tilt angle flying upwind, while maintaining the same ground speed.

I suspect that won't convince you either, though.

Like I said ... there's no point continuing conversation with you.

I'm coming to the same conclusion.

I'm pursuing this discussion for a different reason. Others. It's important that people learn correct information, especially when someone with the esteem, reputation, and standing you have on this board is disseminating incorrect information, and seems unable to admit it.

Despite your insults earlier, I do know a lot about this topic.