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Premise, I'm not interested in speed or any type of sporty flight attitude, but only on range maximization I have

  • 30A ESC,
  • 2212 1400Kv motors 180W max with maximum efficiency current in the range between 6A and 12A, with 16A max current (they can resist just a minute on 16A)

I haven't chosen the battery but it cannot be more than 3S for my hardware.

What battery/propeller configuration can allow me to complete the model in order to achieve the optimal range without overstress motors/risking to fry the equipment?

Are the 1045 propeller suitable for these kinds of motors?

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  • $\begingroup$ the max range occurs by optimizing net energy density in kWh/gm then choose props by matching operating point of required power thrust by matching impedances for MPT. $\endgroup$ Oct 5, 2022 at 15:20

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I think a 10" prop will be far too large for those motors and you should be looking at no more than 8". For maximum range you may even want to go a little smaller to reduce the power. You could use one of the many on-line motor calculators. For example this one suggests that a 10x5 would run at 19amps, while a 8x4 would use 13amps. To get down to 6amps, you'd need a 6x4.

If you want to use big props, you can run the numbers again for a lower Kv motor.

However what you don't know is how much power you need to fly, or the optimum speed to fly at. As you go faster, you need more power but you also cover more distance. Too fast and you're wasting power fighting air resistance, too slow and you're using most of your power just to stay in the air. You need a fixed amount of power to counter your weight, and the rest to counter drag, which increases with the square of your speed.

I would start by designing for twice as much thrust as your weight, so you can spend half your power on moving.

Big slow props are good for hovering and occasional bursts of high power, but for maximum range you want to be cruising at somewhere near full power (otherwise your motors are larger and heavier than necessary). Most photography drones are optimised for duration, not range.

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  • $\begingroup$ Thanks for the reply, but still, the efficiency matter confuses me. Shouldn't the amount of absorption depend on how much you decide to push the engine through ESC control? if I throttle less to keep it under a certain current threshold (e.g., according specs the best efficiency of motor is in 6A-12A range) but with larger propellers that generate more thrust (so more payload potential for a larger battery) or same thrust running at lower speeds, shouldn't I have more efficiency? $\endgroup$
    – AndreaF
    Jul 9, 2022 at 0:45
  • $\begingroup$ Large props are great for hovering efficiency because they push lots of slow air, but you are looking for range, so you need to balance speed and duration. If it's only pushing air slowly, you will only be able to fly slowly. If you have to run at part throttle, you'd be better to use lower Kv motors that could run at full throttle and the same power. $\endgroup$ Jul 10, 2022 at 9:55
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As far as I know the most common way to get the max range for long range quads is to use Li-ion 18650 accums packs. It has relativelly low max current (currently there is 18650 cells with upto 20A current like Samsung INR18650-25R) but the capacity is very high. You can build 3SnP - n depends on your quad size.

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