Hello everyone,
What frame and parts would I need to construct a large sized drone that could fly for over an hour at going around 50MPH and capable of withstanding 40MPH winds.
Thank you 
Do you want the drone to be a multirotor or an airplane?
If it’s a battery powered multirotor, the normal flight time is 15-25 minutes. Some companies have been able to get 30min, but 1 hour does not seem possible at this time.
A Hydrogen powered prototype from HorizonFCT seems to get 4 hours of flight time, but it’s not yet commercial.
A sailplane has more of a chance of staying in the air for 1 hour, but would have issues with 40MPH winds.
Hello Coleman,
I am looking into a multirotor. I am looking to build a drone like the one on the link below but am not looking to spend the $6,000 it is for sale for. Is it even possible to make a drone with these limits or are they just advertising their product better than it is.
Thank you
Their product has very interesting specs…
Assuming they are using a normal 11.1V 10,000mAh LiPo battery (around 800g), and the frame, motors and everything else weighs very little (1Kg for example).
The frame seems to be made out of either carbon fiber or G10, as well as aluminum - standard building materials for drones these days.
At a weight of 1.8Kg, this means each motor + propeller would need to provide at least 450g of thrust without payload to simply counter its own weight (not even take off).
Add a 6lb (2.72Kg) payload, and each motor needs to provide 1.13Kg of thrust. To get off the ground and resist wind, the motor + propeller needs to really be able to provide closer to 1.5Kg of thust.
A safe bet is using a 2:1 ratio, so the motor + propeller should be able to provide twice the thrust needed to counteract the weight, so 2.26Kg each.
If we compare this to a brushless motor where the thrust is known, for example
robotshop.com/en/tmotor-uav- … =RB-Tmo-16
This motor can provide ~1Kg of thrust at 11.1V using a 13 x 4.4 propeller, but would consume 12A.
This is not enough to lift their full payload off the ground (as calculated above), but we’re just checking figures.
Four of these motors operating at maximum thrust would consume 48A.
A 10Ah battery would last 12.5 minutes and the copter would not even take off, let alone be able to fight against 40MPH winds.
If they choose a lower voltage battery, for example 7.4V (which is not common at all), the current required to achieve a certain thrust would increase significantly (Power = voltage x current).
If the chose a higher voltage battery (14.4V), then the battery pack would weight 33% more, while the current may only drop by a factor of 25%.
If we assume the motors they choose are ficticiously “ultra efficient” and only consume 5A at full throttle, that would still only mean a flight time of 20 minutes (likely no payload).
Using current LiPo technology, a flight time, with payload or without, does not seem to be able to provide anywhere close to a 1-1.5 hour flight time.
We suggest you contact them to see if the flight time their advertise is using only one battery or if several batteries are included with the package which need to be swapped every 15-25 minutes.
In regard to your original question " or are they just advertising their product better than it is"… when you see they say “earn up to $150,000 / year flying drone ads”… would you really believe this too?
What company would pay $500 per hour for a small flying banner in a specific location? Note that we say small banner because anything of significant size would act as a sail - something which a single drone cannot handle unless it’s mesh.
What I was emailed back: "Our drone has a longer flight time with no attachments such as a camera or a banner. We have done more recent testing and the flight time is more around 40-45 minutes with attachments… Still impressive.
We use a 10,000mAh battery. Our engineers modify the motors to make them more energy efficient and more powerful. They are customized for promotional advertising/marketing purposes."
So yeah, I think I will buy one of the drones your company makes.
Thank you
This is self evident - a payload decreases the flight time of any aircraft.
So from 1 to 1.5 hours down to 45 minutes. If their battery is 10Ah, that means all four motors consume 15A (10Ah / 15A = 0.66 hours = 40min), or 3.75A per motor.
If they use an 11.1V battery, each motor has a power rating of around 41.6W. Motors in this range tend to provide around 500g of thrust, nowhere near the 1Kg calculated before.
I’m amazed that a small company can modify the motors themselves to make them more efficient and powerful than an actual brushless DC motor manufacturer came up with.
Normally this would involve completely re-wiring all of the coils. They should go into the motor manufacturing business if this is the case.