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

Let's Make Robots Robots
161

@Mahesh It is motor by motor - check before purchasing it (some are CW, some are CCW).

162

@Mahesh You need to know the current draw of the motor at max power, then choose a battery which can discharge at that rate. The capacity is up to you and will affect flight time and weight.

163

Hi Sir, I’m a student of electrical engineering interested in building a quadcopter for cybersecurity purposes around the raspberry pi 3 and want to use it as a flight controller and also to control the power distribution board. I’ve zeroed in on a 450mm quadcopter frame;a set of stands for landing;4 1000Kv Brushless DC motors(2.2Kg thrust each);4 ESCs 30Amp each; 4 10x4.5 propellors;searching for a distribution board;3300mAh battery for motors and 5000mAh power bank for pi 3. Please guide me on the parts that I should add to it and I’d like to know how I could turn the pi3-with astropi HAT for sensors, into a flight controller for the project. Any help and feedback is highly appreciated.

164

@Aritra You need something like the Navio2: https://www.robotshop.com/en/navio2-autopilot-kit-raspberry-pi-2-3.html We offer some power distribution boards / cables here: https://www.robotshop.com/en/uav-drone-power-wiring.html

165

Hi
I am going to upgrade my hexacopter frame. its base is now 550mm and i going to build a new witch is 800mm. My engines are NTM 28-30s 800kv the drone has 2 4 cells battery. the engine prop test is 12x6E - 14.8V / 276W / 18.7A / 1.20kg thrust. My new frame is about 1500g netto so about 2.5 kilos build i think. Since its a hexacopter i calculated that it will lift 3600g on 50% trottle so it should be no problem using this engines? i can maybe encrease the lift more if i use 14 or 15 inch blades?

166

@Per Egil Møller Maybe, but check to see if the motor you are using has any thrust data for propellers. Larger propellers don’t always guarantee efficient thrust.

167

Thank you for your replay, the only prop test of them with value is the 12x6E – 14.8V / 276W / 18.7A / 1.20kg wich i known then to be true, so its should lift fine on 50% trottle and still have a kilo to spare. P cant find nothing more tests of this engine, its from hobbyKing so i have written to them asking for more info since they made them.

168

@Per Egil Møller Knowing the thrust data for at least one propeller with that motor is a great start.

169

Thank you again, my soulution to this is that i am going to use a special design 700mm carbon frame that folds like and umbrella and it has a folding landing gear. This kitt only weigh 650g so with all i would like to have on it including two batteries i will be around 1700g finnish with gimbal and two cameras. Since the engines lift 3600g on 50% i would have good flight time too.

170

Hi Sir, I have a doubt. If I plan to built a drone that carry 1.5kg object, what motor and propeller I prefer to choose. Any suggestion?

171

@Alexander The maximum thrust from each motor and propeller (combined), multiplied by the number of motors used, should be double the total weight of the drone (including the payload). Therefore if your drone weighs 4.5Kg, and the payload is 1.5Kg, and you are using a quadcopter design, that means the thrust from each motor should be [(4.5Kg + 1.5Kg) / 4] x 2 = 3Kg. Therefore you would need to find a combination of motor + propeller which provides 3Kg at max thrust.

172

Hi
I need materials that explain methods of how to design propellers according to my performance necesseties of the drone… do you know where can i find it or any sugestion for starting this type of project?
Thanks

173

@Gabriel Unfortunately not when it comes to the design of propellers and the aerodynamics involved.

174

What about the pc cooling fan ?? For a drone… for a model display.I want to just take off

175

@Krish Unfortunately not enough thrust to even lift its own weight.

176

Hi Coleman,

I am designing a drone for use with the ambulance service for my university dissertation. At the moment I know that my drone will weigh around 7kg, and need to achieve a speed of around 40-45ms. I’m currently trying to work out the power/thrust required for the motor and prop sizing so that I can choose the best-suited frame type. Do you have any advice on where to start with these calculations?

Thanks, Dom

177

@Dom That’s a really heavy drone. If you opt for a quactoper design, each motor + propeller combination needs to be able to lift 1.75Kg at half thrust. You don’t need any calcuations - just look at motor spec sheets for thrust data using specific propellers at specific voltages.

178

its highly appreciable information thanks for provide these important knowledge

179

I want a thrust of min 1kg and i want to use short length propellers like upto 10 to 12cm
Suggest me the kv of motor and current rating of ESCs and battery amps required
Please!

180

@Yash You’ll need to read the specs of each motor to know the thrust they can provide with a given propeller. KV does not directly relate to thrust. If you have a quadcopter which weighs a total of 1Kg, the total thrust per motor will need to be 500g. The ESC relates to the motor’s max current and voltage. The battery pack relates to the total flight time you want, as well as the motor’s nominal operating voltage (for the thrust you need).