Welcome to PhantomPilots.com

Sign up for a weekly email of the latest drone news & information

Math Equation of Flight Time VS Weight..

Discussion in 'Phantom 2 Vision Discussion' started by rfernandez, Apr 23, 2014.

  1. rfernandez

    Joined:
    Jan 20, 2014
    Messages:
    373
    Likes Received:
    0
    Has any of the engineers in this forum have come up with an equation for flight time versus added weight?
    FYI forget about the 1 second per gram bit.. it does not add up, My Taco-RC gimbal with FC-200 camera weights in at 165g
    Now if I use that in an equation of FT= AW/time. Where 165g /60 = 2.75 (2min. 45 sec). FT= flight time, AW = added weight.
    Variables to take in to account are the added electrical consumption of the gimbal motors and gimbal controller.

    I wrote an email to Taco-RC and their response was that the 2208 motors should consume less than 1 amp. I looked up the specs and i found the following: Constant current is 6A, No load current is 0.6A And Peak is 12A.

    If you take the average weight of a stock Phantom is 1165g RTF. Mine with the gimbal weights in at 1330g and I am getting on average 16.5 to 17.5 min landing with at to around 18% of battery left.
    Now something here does not add up, so there has to be a valid equation to predict flight time reduction to weight added,

    Now that is something to bake ones noodle... :) :) :arrow: :evil:
     
  2. grochester

    Joined:
    Dec 29, 2013
    Messages:
    114
    Likes Received:
    0
    Location:
    Canada
    Possibly a non-linear equation. For example, extra motor rotations required for lift may not be directly proportional to extra weight lifted due to the fluid dynamics of air and efficiency of propellers.
     
  3. Cr8tive_leo

    Joined:
    Feb 6, 2014
    Messages:
    255
    Likes Received:
    1
    Location:
    Ontario, Canada
    Air density/pressure, wind, all sorts of numbers for the equation. Also the health of your battery.
     
  4. brushlesheaven

    Joined:
    Jan 29, 2014
    Messages:
    250
    Likes Received:
    6
    Thats right and did anyone do any testing on
    our original P2V lipo battery. I know from my expierience so fare
    with lipos that there is no 2 the same 5200 mah ( real 5200 mah )lipase out there...
     
  5. SlackerATX

    Joined:
    Mar 15, 2014
    Messages:
    177
    Likes Received:
    3
    Location:
    Austin, TX
    How balanced the gimbal is...wind speed...aggressive flying. In general what % of the time the gimbal sits outside it's natural position and the force required to maintain that position. (Not to mention the obvious power and PID setting that will directly impact battery consumption)
     
  6. rfernandez

    Joined:
    Jan 20, 2014
    Messages:
    373
    Likes Received:
    0
    I was not looking for a precise equation but a general rule of thumb. I know about the variables and we don't have all the numbers needed to make it a precise number< but close is good enough to get an Idea.
    Here are the numbers that I do have:

    Battery at 100% at take off
    landing at around 18% capacity
    Total Flight time 16:32
    Gross wight 1330g
    Battery Life at 93%, No 2 at 93% no. 3 at 98%
    Stock Props. near perfect balance (video is perfectly smooth )
    TACO_RC Gimbal with V3 Shell
    ALT Pressure at 29.98
    winds 220/5 kts
    No aggressive movements.

    Roll: P=10, I=.1, D=19, Power=110,
    Pitch: P=10, I=.1, D=19, Power=90,
     

    Attached Files: