What is required for more flying time?

After doing so many calculation I am stuck at

how can I increase the flying time and without compromising the maximum height

Steps considered

1. Reducing weight

2. Low Kv or high Kv motors

3. smaller prop or bigger prop

4. prop pitch

5. Hgher capacity battery (but it adds weight)

6. lower internal resistance of battery

7. anything else.

Suggestions needed

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –


  • I think I am stuck with the equation of low Kv but large props.

    Does someone tell what is the motor, Kv and prop size for MD4-200

  • Developer

    Better efficiency is the key :

    Here is a non limitative list :

    - lower weight

    - better battery capacity / weight ratio

    - lighter and more rigid propeller (wood or carbon), good balancing

    - variable pitch propellers

    - high efficiency motors and ESCs, high voltage to avoid iron loss.

    - optimal frame / motors / propellers matching

    - advanced brushless motor control (vector control) with regenerative braking

    - smooth and optimal control of motors to avoid energy loss

    - smooth driving !

  • I think what you need is one large propeller, instead of several small inefficient ones.  Turn them much slower than you currently are. Might need gear reduction.  Since you only have one propeller, you obviously would only need one large, high voltage (8S-12S), efficient motor and speed controller.  But since you only have one propeller, you'll need to be able to vector the thrust so that you have control.  While you're at it, use a one-way bearing so that if the motor stops for any reason, you can still auto-gyro down to the ground instead of falling.


    Oh wait.  That's describing a traditional heli. ;)  :p

  • Thats about what I came up with too.  I decided to go with:

    motors: 750kv motors rated 20a MAX, 15v / 12a,15v continuous- in a 28mmx30mm package

    battery: 5000mah 4S Li-Po 14.8V @ 25C

    props: 10-6 three blade

    esc: turnigy plush 25a

    I found this combo should give my machine the best run times and thrust:weight ratio.  At 1400gms and almost 1000gms thrust per motor (4Kg total thrust MAX) should provide about 2.8G's of acceleration @MAX.  Thrust to weight ratio is very important. 

    The way I figure it,I should see hover @ about 35% throttle or about 65W per motor.  MAX acceleration should consume almost 300W per motor which puts flight time into the five minutes range.  Using lowest possible power for hover gives longest flight time.  Since thrust depends on actual power (mechanical- ie, minus all efficiency losses) delivered to the props, using higher voltage lowers the current draw to give the same power output.  Batteries are rated in Ah (or mAh) and therefore flight time is a function of current draw.  Trading voltage for amperage in P=VI gives longer flight times.  Raise voltage, use slower motors and more aggressive props.  Lower resistance everywhere (batt, esc, wiring) is crucial.

This reply was deleted.


DIY Robocars via Twitter
RT @_JonMyer: 🚨Attention DeepRacer's including #UndergroundDeepRacer🚨 Check our our LIVE stream that including @IAM_dbro Take a few moments…
DIY Drones via Twitter
RT @MarvelmindMaxim: Extreme precision for 60 swarming robots. #marvelmind #autonomousrobotics #robotics #swarmrobotics #rtls #ips #indoor…
DIY Drones via Twitter
RT @MarvelmindMaxim: Precise (±2cm) tracking for racing boats and autonomous boats. Works outdoor and indoor. #autonomous #AutonomousVehic…
DIY Drones via Twitter
RT @MarvelmindMaxim: Helping PixHawk folks to fly autonomous quadcopters using PX4 and ArduPilot. https://marvelmind.com/drones/ Equally suitab…
DIY Robocars via Twitter
RT @chr1sa: The @DIYRobocars @donkey_car virtual AI car race is starting in 15 minutes! Watch it live on Twitch https://www.twitch.tv/mossmann3333 htt…
DIY Robocars via Twitter
RT @chr1sa: Don't miss our monthly @DIYRobocars @donkey_car virtual AI car race tomorrow at 10:00am PT live on Twitch. Head-to-head racing…
Jul 31
DIY Robocars via Twitter
RT @sparkfun: Our completed tutorial on building an @NVIDIA Jetson Nano-powered @Sphero RVR gets your bot up and running via teleoperation…
Jul 30
DIY Robocars via Twitter
RT @SmallpixelCar: Freeway test https://t.co/4V5tV9lhIP
Jul 29
DIY Robocars via Twitter
Very small autonomous cars racing, thanks to an overhead camera: https://control.ee.ethz.ch/research/team-projects/autonomous-rc-car-racing.html
Jul 29
DIY Robocars via Twitter
Jul 29
DIY Robocars via Twitter
Jul 29
DIY Robocars via Twitter
RT @chr1sa: Don't miss our virtual AI car race this Saturday! Real developers + virtual cars =🏎️🏎️🏎️ Head-to-head battles with thrills, sp…
Jul 28
DIY Robocars via Twitter
Jul 27
DIY Robocars via Twitter
RT @usashirou1: Jetson nano by Isaac Kaya #jetson https://t.co/Mu1N0CyQkN
Jul 23
DIY Robocars via Twitter
RT @GPUsolution: JetRacer mady by Iflytek company #JetsonNANO #Nvidia https://t.co/MimTymIwge
Jul 23
DIY Robocars via Twitter
RT @openmvcam: I love this: Mega or Mini? Image Classification on the 1MB OpenMV Cam H7 by Ish Ot Jr. in OpenMV, Edge Impulse, Internet of…
Jul 23