Best way to get the longest distance

I would say its close to the top speed of the quad then since most of the battery is consumed fighting gravity. Maybe in the 70-80% range. If we can find the datasheet for the engines we can find their maximum efficiency point and that could be translated into speed.
 
Drag force: in the formula velocity is to the square, therfore twice the speed is 4 times the drag and 3 times the speed is 9 times the drag....... Many long rangers have experimented with their phantom and the sweet spot seems to be 30-32 mph. Above this speed (depending on temp. and humidity) is most probably where drag becomes a greater force on the bird than gravity. The only better way to have a more precise speed value if some one would have access to a wind tunnel... (Would pilots with wind tunnels please step forward.) IMO if you want distance the place to be is where drag and gravity forces are equal. There are more variables but these two are the big ones.
 
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At a constant speed total distance travelled = speed x time.
so if we flew at 30mph(1/2 mile every minute) for 20 minutes you would cover 10 miles.
If you flew at 15mph you would have to fly for 40 minutes to cover the same distance.
As said before most of the energy expended is just to keep the aircraft airborne, and only a fraction extra is needed to provide forward movement.
The maximum flight time would be in a hover with speed = 0mph. I don't know the figures for a P4 but let's speculate it's 25 minutes.
At full speed it will drop to say 18 minutes. If you were to draw a graph of time v speed for various speeds between 0 and max speed I predict it would be pretty linear, with the greatest distance travelled at max speed. The flight time lost at higher speeds will be more than compensated for by the extra distance travelled at the higher speed.
 
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At a constant speed total distance travelled = speed x time.
so if we flew at 30mph(1/2 mile every minute) for 20 minutes you would cover 10 miles.
If you flew at 15mph you would have to fly for 40 minutes to cover the same distance.
As said before most of the energy expended is just to keep the aircraft airborne, and only a fraction extra is needed to provide forward movement.
The maximum flight time would be in a hover with speed = 0mph. I don't know the figures for a P4 but let's speculate it's 25 minutes.
At full speed it will drop to say 18 minutes. If you were to draw a graph of time v speed for various speeds between 0 and max speed I predict it would be pretty linear, with the greatest distance travelled at max speed. The flight time lost at higher speeds will be more than compensated for by the extra distance travelled at the higher speed.

So for any Phantom 2/3/4 if you want to get somewhere far and still come back the best way is to go full throttle on it in ATTI mode ?
 
So for any Phantom 2/3/4 if you want to get somewhere far and still come back the best way is to go full throttle on it in ATTI mode ?

I would say so.
lowering speed will give a longer flight time but I don't believe you would gain enough to come close to compensating for the effect of the reduced speed.

I have a phantom 3 and I think 20 minutes at 30mph is probably achievable if not changing altitude so would give a max range of 10 miles. If I dropped my speed to 25mph i would need to fly for 24 minutes to cover 10 miles, at 20mph it goes up to 30 minutes and 40 minutes for 15mph.
As the speed drops, the flight times nessesary quickly become unachievable.

Obviously for a long distant flight, choosing the point to return at will be critical and will be affected by wind speed and direction.
 
Lots of good points have been taken into account. Here's one more very important one difficult to measure. Prop slip! Hight Rpm = more slip = less efficient, so going all out has a cost. Someone in another post mentioned trying to keep rpm around 5300 (I think). The laws of conservation of energy are all around us, you can be efficient or fast but you can't have both at the same time. The good thing here guy's is that we are trying to figure it out and make our birds go farther and longer and make us better pilots. Flying these birds is a whole lot more than pushing the sticks, I like it.
 
Go slow, straight and steady or balls to the walls fast? I am sure someone knows the physics and formula to figure battery drain etc that could calculate how far you can go in both scenarios.
Slow but less drain on battery
Fast draining battery faster but covering more distance.

Also does having gps on hurt? I imagine as long as your motion that it wouldn't as it would use energy to have to lock into a position. But if you were going with a tail wind you may gain more distance in ATI mode so you can give it some gas and drift. That would be a little scary as you could get further out then your battery can get you back fighting the wind coming back
Lawman you can start read from this thread. It does a lot of info on the long flights and or ask one of the guys there also.
Maxx VS Terminator. Long distance antenna shootout!
 
Go slow, straight and steady or balls to the walls fast? I am sure someone knows the physics and formula to figure battery drain etc that could calculate how far you can go in both scenarios.
Slow but less drain on battery
Fast draining battery faster but covering more distance.

Also does having gps on hurt? I imagine as long as your motion that it wouldn't as it would use energy to have to lock into a position. But if you were going with a tail wind you may gain more distance in ATI mode so you can give it some gas and drift. That would be a little scary as you could get further out then your battery can get you back fighting the wind coming back
Wonder how long or if it would fly in zero gravity?
 
Go slow, straight and steady or balls to the walls fast?

Because multi-rotors expend most of their energy maintaining altitude, the best range speed (as opposed to max endurance) is max throttle, esp if flying in a headwind, as the less time spent in the headwind, the better.

The only real factor/variable that comes into play is additional wind resistance due to higher speed, (which increases as a square of the speed...like, go 2 times as fast and wind resistance increases by a factor of 4). But that doesn't much come into play at Phantom speeds, and in any case, the additional power needed by the Phantom to maintain a faster speed is much less than the additional power needed to fly for the additional time at the slower speed.

All the other variables, like temperature and air pressure (and altitude) and such, make a (small) difference, but only if a person can choose the day/time they will fly.

The only technique for getting more range (using less battery) would be to descend at a rate so the multi-rotor reaches the ground at the same time it reaches the landing zone, so you're not spending time descending from cruise altitude right over the landing zone.
 
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Because multi-rotors expend most of their energy maintaining altitude, the best range speed (as opposed to max endurance) is max throttle, esp if flying in a headwind, as the less time spent in the headwind, the better.

The only real factor/variable that comes into play is additional wind resistance due to higher speed, (which increases as a square of the speed...like, go 2 times as fast and wind resistance increases by a factor of 4). But that doesn't much come into play at Phantom speeds, and in any case, the additional power needed by the Phantom to maintain a faster speed is much less than the additional power needed to fly for the additional time at the slower speed.

All the other variables, like temperature and air pressure (and altitude) and such, make a (small) difference, but only if a person can choose the day/time they will fly.

The only technique for getting more range (using less battery) would be to descend at a rate so the multi-rotor reaches the ground at the same time it reaches the landing zone, so you're not spending time descending from cruise altitude right over the landing zone.
I know from flying in wind it may take 1 to go out but 6 or 7 minutes to come back. I've done my best with a P3a with no wind. 18k
With that said I have done not to bad with my P2v+ with a little wind. 8.5k I was going with the wind (which is really a no no) out.
 
As a helicopter pilot I can tell you that there is a certain airspeed where the rotor will be most efficient ... and there's something called "translational lift", caused by the advancing blades moving into the air passing over the forward moving helicopter ... which results in more lift at the same power setting .. or the same lift at a lower power setting .. which means more efficient .. but don't have a clue how to measure except through trial and error ... flying the same distance to/from and looking at the battery energy consumption. Also, drag increases with increasing airspeed .. so there's an airspeed where translational lift advantage is overcome by increasing drag w. increasing airspeed ... Good reason for some test flights!
 
As a helicopter pilot I can tell you that there is a certain airspeed where the rotor will be most efficient ... and there's something called "translational lift", caused by the advancing blades moving into the air passing over the forward moving helicopter ... which results in more lift at the same power setting .. or the same lift at a lower power setting .. which means more efficient .. but don't have a clue how to measure except through trial and error ... flying the same distance to/from and looking at the battery energy consumption. Also, drag increases with increasing airspeed .. so there's an airspeed where translational lift advantage is overcome by increasing drag w. increasing airspeed ... Good reason for some test flights!
Flitedoc it sounds like you are the pro compared to me. I'm just the guy out flying his hobby drone and loving it.
 
As a helicopter pilot I can tell you that there is a certain airspeed where the rotor will be most efficient ... and there's something called "translational lift", caused by the advancing blades moving into the air passing over the forward moving helicopter ... which results in more lift at the same power setting .. or the same lift at a lower power setting .. which means more efficient .. but don't have a clue how to measure except through trial and error ... flying the same distance to/from and looking at the battery energy consumption. Also, drag increases with increasing airspeed .. so there's an airspeed where translational lift advantage is overcome by increasing drag w. increasing airspeed ... Good reason for some test flights!

Not to get off on a tangent, but translational lift is what I've been trying to suggest to everyone that's been complaining about the phantom slightly dropping altitude when coming to an sudden hover from fast forward motion. Granted, the Phantom doesn't have collective on the rotors (although I think it would be kind of slick) but I am assuming the concept would still apply
 
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Put two of these babies and run only the best LMR-400 cable
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As a helicopter pilot I can tell you that there is a certain airspeed where the rotor will be most efficient ... and there's something called "translational lift", caused by the advancing blades moving into the air passing over the forward moving helicopter ... which results in more lift at the same power setting .. or the same lift at a lower power setting .. which means more efficient .. but don't have a clue how to measure except through trial and error ... flying the same distance to/from and looking at the battery energy consumption. Also, drag increases with increasing airspeed .. so there's an airspeed where translational lift advantage is overcome by increasing drag w. increasing airspeed ... Good reason for some test flights!
I've been playing with this and it seems in sport mode, just low of the blue RPM, or just above the green "low end" cutoff, seems to be the most efficient to me.


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So ... Does rapid ascent to use more battery than slow ascent? I live in the woods and have to take off straight up to whatever altitude before I can transition to horizontal flight.
 
It wouldn't fly at all.
Zero gravity would mean no atmosphere for the props to grip!!!
There is zero gravity in the ISS, and an atmosphere, it would fly up there

Er, microgravity anyway

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It seems that slow ascents and descents are the most efficient. Now, if you are talking a vertical ascent to above tree level I think you should be okay to rise to that level and then slowly ascend as you fly out. It will really eat your battery if you fly up to say 200' vertical before you start flying horizontal.
 
So ... Does rapid ascent to use more battery than slow ascent? I live in the woods and have to take off straight up to whatever altitude before I can transition to horizontal flight.
What I like to do when going for distance is goto sport mode, and fly just above the green zone, meaning about 4500-5000rpms, and then a 1 to 3 ascent, meaning if going 17mph Hz, then 5 or 6mph Vertical, even better is 1/4 or 1/6th, flying at 20mph forward and can do 3 or 4 mph up.
It's also better to sometimes leave in P mode but it seems more efficient at 20mph-25mph


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