How to Make a Drone / UAV – Lesson 3: Propulsion

@Rutuja You rarely need a computer when operating a drone; the ground control station is used primarily when you have a controller in a box, a large video display, several transmitters and receivers (and possibly a computer), and sometimes a larger directional antenna. For waypoint navigation however, the GPS coordinates are saved on the drone itself, after which the computer is not needed unless you are getting feedback. What are your objectives?

Thank you so much for your reply coleman. The objective of our project is to develop a Drone having capability of handling payload of 1.5 Kg and should be able to travel for a distance of 8 Km.

Hi Coleman Benson,
It was really very helpful and informative link. Can you please help me out in solving a small query?
If payload is 5Kg including everything(battery,frame,etc.) ,Propeller Size is 13 inches with 4 blades and overall size is 32 inches. Then what battery specs should i choose… So that it can get 10 Kg of thrust. Don’t include ESC and motor specs for now.
i.e. , can 10000mAh provide me a thrust of 10kg.
Thanks in advance…

@Avi You need to know the specifications of your motors when you use 13" propellers while operated at a specific voltage. The battery does not determine thrust. If you don’t have these specs, you might need to do some testing. A 10Ah battery pack is actually quite large and heavy (are you certain that’s within your 5Kg total weight?).

Hi Coleman, The requirement of our project is to have thrust generation of 600 g. Can you please suggest the suitable motor, propeller ESC combination for our thrust requirement.

@Rutuja To choose the right power system, you need to know the total weight of your assembly including everything. Motors are rated at maximum thrust production. If you need a total of 600g including everything, many choices are available. Here is a suggestion:
T-Motor AIR 350 Multirotor Kit

Sir actually these lesson will be also helpful for my cllg project ty so much…:slight_smile:

How do you pair a motor to an ESC? I know the ESC needs to be able to handle the maximum amount of current, but what about the voltage? Does it matter? The ESCs I have seen have had a much lower input voltage than the motor.

@Nate Most ESCs should have a voltage rating (or min/max). Since the common voltages used by brrushless DC motors for hobby use are 3S (11.1V) or 4S (14.4V), some manufacturers simply make the assumption that this is what you’ll apply and don’t list the specs on the ESC. If you’re not sure, it’s best to contact the manufacturer.

sir i want to make a drone which can carry approx 5-6 kg weight and flight time around 30 min,so for these which battery and motor i should select as in according to there specs

@vaibhav Patil 5-6Kg payload is actually quite a bit, especially if you also want a 30 min flight time (which means a lot of batteries). Take a look at the procedure for choosing motors and propellers and we suggest considering at least a hexacopter design.

Yes sir i am going to make hexacopter only so for that i am thinking of using two Multistar 10000Amh batteries and 940kv bldc motor and depending upon these what size propellers i should select , will these be enough to achieve my target ?

@vaibhav Patil Two 10,000mAh batteries (likely 11.1V?) are quite heavy - that makes for a very large hexacopter. Can you find a large BLDC motor which provides thrust based on propeller size? You will likely be considering propellers in the 14" (or larger) range.

Can I have some Regression Models (benchmarking) of Key Parameters of proven Electric-powered UAVs with Fixed Wings, please? Many thanks in advance.

@K.Mohan: We do not have regression analysis of fixed wings UAVs to share. You can probably find some by performing an online search.

Starting with a Tarot Iron Man 650 building my first UAV. Learning lots and thanks so much for this publication. Looking at props I keep finding matched pairs with one a CW and one a CCW. Can you please tell me why props are sold in matched pairs of CW and CCW?

@Jonas Woodruff Almost all multirotor UAVs are symmetric about the center axis and as such, the propellers need to spin in the opposite direction. Selling the propellers in pairs decreases the chance that customers will buy the wrong quantities of each type of prop.

Sir I have not understood the concept of angle of attack and blade pitch.could u please guide me!

@Abhishek Think of a propeller blade like part of a screw: it has a certain pitch and angle. The distance traveled for one revolution of the propeller is the pitch, whcih also relates to the angle of attack. If you find a resource online where you feel the explanation is better described or presented, we invite you to bring it to our attention.

Hi :slight_smile: I need some guidance. I want to make a tricopter for my paper license and i want to calculate the thrust for my propellers. But i can’t find anywhere how to calculate. I need some mathematical formulas. I found for planes. Is it the same formula? can i use that for my propeller for tricopter?