Building Drone from Scratch


#1

Hi All,

I am building a drone from scratch as a beginner. I not going for something complicated, I just need it to fly for about 60min or so, with a camera on it. basically an FPV drone with perhaps a bit more flight range. I shall upload material & progress evidence as I go along with it.

I have calculated it to be 700g total wieght, this means:
700gX2=1400g total thrust needed
1400g/4=350g

My frame (awaiting delivery) with sized at 215mm (wheelbase)
thus through reading up figured 5x4.5x3 props would do the trick.

I am currently going through motor selection based on the above information.

kindly advise if you pick up on something I should look out for, or could do better?

Much Thanks


#2

Hey Moe,
I think a flight time of 60min is a bit too much…
A Motor that would fit your needs is probably a 1806 one with high effiency…

Luca :slight_smile:


#3

As @luca said, if you want to fly for 60min you will need to use much more efficient motors. Also the onto quadcopter a that can fly this long usually use 22 inch propellers, and each motor costs a few hundred dollars :money_with_wings:. Motors like the t motor u8 are quite popular for long flight quadcopters.

The only way you can do this is if you get ahold of a stark industries arc reactor. And if you find one please let us know :slight_smile:


#4

A post was split to a new topic: Changing Flight Controller Software


#5

Hi, for your build, not only will you need a lot more efficient motor/propeller combo (definitely not 5-inch propellers), but you will also need to have way higher than double the AUW in thrust to fly efficiently, this is something I learned from my own builds.

For context, the reason DJI are able to get drones like the Mavic to fly for almost 30 mins is because they total thrust available is over 3 times the AUW of the craft. So, for 60 min flight time you’re probably looking at a quadcopter with 10kg max thrust and 3kg AUW, half of that being batteries.

Try and get the lightest motors, propellers and frame possible for this, a good place to check out would be the Sunnysky efficiency series motors and T-motor props. Good luck!


#6

Yes good point it’s all about making your motors run at optimal efficiency which is usually at lower thrust values when they are not working very hard.

Install about this in more detail here


#7

Hi All,

Many thanks for the words of advise, it really helps a lot. I heed the advise of not going too big on the drone as a first timer.

I have chosen a 450mm frame size, negotiating between being small and large quad. This frame has the following recommended components:
a) 22-28mm motors with 800-1200Kv
b) 15-30Amp ESC (recommend 30A OPTO)
c) 8x4-10x4.5 Props (2CW and 2CCW)
d) Multi-Rotor control board (recommend KK2.1)
e) 1500-2200mAH 3s 11.1v Lipoly battery

based on the frame I figured I can work on 9x4 props (within recommended range by frame), I will aim for two blade as these are said to be more efficient than three blade. I can then have room to enlarge if motor selection issues are encountered.

I have a weight of 1210g, thus total thrust of 3630g. this meas each motor should give 907.5g

So the challenge i meet now is that the motor thrust data tables I am looking at are all around 5-6 in efficiency. these are cobra motors so far im looking at. These are cobra motors, 6 of these that I am looking at. I start with the propeller, then the thrust, then I end with the efficiency of the motor.

  1. Please advise if I am on track, as I need to select the best motor-propeller combination, with an efficient motor?

  2. A 10-inch prop gives me lesser thrust (approx 726g), with efficiency of 7.05. A 9-inch prop gives me 1068g of thrust, but at 5.41 efficiency? This is for the same motor. This scenario is what makes me ask the above question (1.)

:slightly_smiling_face:


#8

Hi, I think you are worried to a good start but I suggest you change the following.

1- don’t use kk2.1, rather go for an apm2.8 if you want something cheap, reason is APM gives you alot more functionality such as GPS return to home and auto hover.
2- I suggest you use a bigger battery if you can, maybe a 3000mAh with a lower C rating of about 15 to keep it light.

As for your questions I suggest you read this guide How to choose the right motor for your multicopter drone as it answers your questions about motors… but I think you are on the right track :slight_smile: