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  1. lawman0210

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    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
     
  2. 30secs

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    Tail wind, atti, around 60-80% pitch. That's what I've gathered thus far.

    Also, since we're talking miles.. Good reception is a factor as well.
     
  3. Ron Armour

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    Same physics that apply to driving an automobile. Your enemy is air resistance. The resistance increases exponentially with the speed......slower is better. I drive a Tesla....ask me how I know that.
     
  4. bernek

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    I wouldn't agree compltetly since the airplane needs power also to hold itself into the air. The automobile can sit relaxed on the ground. The true balance between airspeed and the max distance covered can be calculated but its not as simple as you might think. Things that should be taken into the calculation should be: Wh of the battery, sweet spot for motor eficiency, air density, weight of the aircraft and so on.

    The air resistance moving forward is the less important factor in this calculation since the average speed of these quads are quite low to be talking real aerodynamics but the wind direction and speed is an important factor. I'm trying to say that in no wind conditions flying at around 20-30 miles per hour the aerodynamics are not worth taking into account due to the form factor of these quads.

    This is purely my opinion.
     
  5. Ron Armour

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    Fly a drone into a 20 mph headwind and watch the battery level...........this is the same thing as flying 20 mph faster. To get great mileage, draft your drone behind a big truck like I did with my Tesla when it was low on energy. Same physics apply.
     
  6. bernek

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    So you are saying that flying at 20 mph wind a front facing wind of 20 miles miles per hour is like flying at 40 mph with no wind at all ? I really don't know a lot about static pressure and all the stuff maybe someone with decent physics/aerodynamics understanding can clarify this for us.

    We both know that drafting a drone is not possible but the example is funny. Also please take in account the fact that it also consumes energy to be airborne and that is maybe the biggest factor ! I'm trying to say that slow isn't allways better especially with aircrafts. You might get some wind resistance due to aerodynamics but if you move faster you wont consume a lot of energy just standing almost still in the air. Think about airplanes they fly at around 600-800 miles per hour do you think if they fly at 400 or 300 they could cover up more distance ? I doubt it :)
     
  7. alokbhargava

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    Don't forget the height too. Higher it flies, props need to do more work this more power it needs to remain at that height.

    So the important parameters for a drone are its altitude, wind speed, and it's speed.
     
  8. Ron Armour

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    Air resistance is your single biggest enemy whether you are a car, truck, baseball, arrow or drone.It takes over 700 HP for a car to reach 200 mph, mainly to overcome air resistance. Planes fly at 30K feet because of very low air resistance....the air is less dense. A car will get about 40% better mileage at 50 mph versus 70 mph, mostly due to air resistance. Internal frictional losses are not nearly as big a factor as air resistance. As far as altitude, 2 or 300 feet will not be much of a factor....go up to 10k feet, thats another story....you will need different props for the thin air. If only we could get rid of those pesky air molecules.
     
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  9. 30secs

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    How about some usable answers.. I think around 20-25mph equates to a car's 45mph optimal efficiency levels. That's just bro science mind you.

    I know sport mode will not get you further. I know that i know that OA, video and GPS will reduce life.. Probably in that order.

    I know that drifting at 10mph speed isn't better for distance. Tried it this weekend.

    My best effort was tail atti and going at ~70% forward
     
  10. Ron Armour

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    For a car your best efficiency is operating at max torque. I have not seen any efficiency curves for a P4, but I know that electric motors create max torque at zero rpm so they are much more efficient than a gas engine. As an engineer my best guess for max efficiency on a P4, or P3 for that matter is somewhere in the 12-18 mph range. To really find out, you would have to do some very controlled flights at different speeds under the same exact conditions. This is possible using Course Lock or Waypoints and battery data at various speeds.
     
  11. 30secs

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    That makes sense as the p4 battery last the longest at hover, but I believe the OPs question is optimal distance vs battery life. I I doubt it's 10mph as the battery will have to last twice as long to compete with 20mph drive.. But I could be wrong.

    I would love to see a curve graph after we get some real stats. Will be very useful (dare I say vital) when journeying back on low voltage.
     
  12. Meta4

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    One factor that isn't a big concern in cars is gravity.
    That's a bigger factor than air resistance for a Phantom.
    It uses most of it's power overcoming gravity whether hovering or flying.

    Rather than reinvent the wheel all over again .... there's a lot of good info here:
    Ideal forward speed for max. distance on a charge?
     
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  13. TheLightSpeedz

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    I've done both... I've found in little wind, 29 to 31 MPH will get you the farthest. I steady a 30.5 if I can, or 29, if I can, and on the way out I climb very slow to 300' to 400' depending. Once you get way out and you think "oh ****"... Turn around. If you come back at 30.5 and descend very slow, your motors will keep a lesser RPM on the way back and you'll see your chances of making it home increase.

    On the way back I chase the "h" to get it back under the clock time.

    Trial and error buddy. Most of what I learned I got by ready Dirty Bum.


    Sent from my iPhone using PhantomPilots mobile app
     
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  14. Erised

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    From what I read and do TheLightSpeedz way is the all around best long run solution.
     
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  15. Ron Armour

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    "One factor that isn't a big concern in cars is gravity.
    That's a bigger factor than air resistance for a Phantom."

    If we are trying to determine the ideal speed for max range, gravity is not a concern since it does not change regardless of speed. Air resistance changes big time with speed.
     
  16. Meta4

    Meta4 Moderator
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    Gravity is a huge factor - it doesn't change, it's there all the time whether the Phantom is going fast or slowly..
    Unlike your car, the Phantom uses most of it's battery fighting gravity.
    The slower you fly, the more energy used in holding the Phantom up in the air.
     
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  17. George Race

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    Too bad there is not a simple way to deploy some kid of a lifting "wing" surface, on the drone, that could provide a bit of lift from head wind. Could possibly make climbing to altitude less power consuming.
     
  18. bernek

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    What about gravity ? :)
     
  19. bernek

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    I completly agree on this. We are mixing cars and aircrafts like apples and lemons. Why we talk about weight in all of our hobby ? Because its the most important thing...

    I think 80% of the battery maybe more its consumed no matter what fighting gravity and the rest of 20% is consumed by speed and manouvers. During all this time gravity is chewing battery Wh.

    The same goes for planes and helicopters they talk about flying time available. When you refer to a plane autonomy you don't say it can travel 3000 miles you say it can stay in the air for 8 hours for example. (this show how much gravity plays a role in aeronautics).
     
  20. Ron Armour

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    You guys are missing the point here......Gravity is a constant regardless of what speed we fly. We are trying to determine the best speed to fly to get max range. To do that we can ignore gravity because it is always a constant. The important factor is air resistance because it changes with speed unlike gravity. You all know that if you have a tailwind you travel farther on a battery.....less on a headwind. Air resistance is the determining factor affecting battery life, not gravity.
     
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