How do quadcopters work? – Series – Introduction

quadcopter series, introduction how do quadcopters work

I’m in the process of building a quad.  It’s a modest quad, but it is bigger than the Cheerson.

Because this is a new hobby for me, I’m having to learn a lot of it from scratch.  There is a lot of great information about quadcopters on the internet. Some of it- like Oscar Liang’s blog and Bruce Simpson’s Youtube channel (RC Model Reviews) – is comprehensive and helpful.

But most of it is scattered about in forums and Youtube videos.  Because of this, I’ve decided to kick off this blog with a series about how quadcopters work. You can think of it as my personal notes as I teach myself this hobby. It is definitely a beginner series but I hope it will be useful for a wide range of  people.


Quadcopters are complicated machines. As I’ve been trying to piece together how they work, I see 3 different systems working together.

Power Conversion System

power system, battery, esc, motor, propeller

I’m an engineer, not an artist.

First is the power conversion system. The power system consists of the propellers, the motors, the motor speed controllers (ESC’s) and the battery.

Why is it called the power conversion system? Because this system starts as chemical energy stored in the battery and is converted to electricity.  The motor then converts the electrical energy into mechanical rotation.  This rotation produces thrust via the propellers.

Mechanical System

The second system is the mechanical.  Every part of the quadcopter is part of this system because every part of the quadcopter has mechanical properties.  For example, the overall weight of the quadcopter depends on each component and can greatly affect performance and flight time.

The one component that stands out in the mechanical system is the frame.  While not the most exciting component, the frame is one of the most important components.  Once you pick your frame, you’ve set limits on the size of your quadcopter, how big the props can be, how heavy it can be and what sorts of accessories you can put on it.

Control System

The last system is the control system. control system, transmitter, flight controller, sensors The control system consists of the transmitter that you use to give commands and the flight controller that converts those commands into instructions for the ESC’s.  The control system not only takes commands from the transmitter but also incorporates feedback via various sensors.  This feedback allows better user control, greater stability, and robustness to disturbances.  All the parts of the control system work together and talk to each other using various RC protocols.

Wrapping Up

As I said above, this series is meant for beginners.  That doesn’t mean I won’t go into details on each of the parts.  I just hope to make this understandable even if you have no clue how quadcopters work.

I haven’t planned it all out yet but I would anticipate 12 to 15 posts that explore all the topics I briefly described above.  I hope to publish 1 about once a week.

The next post in the series covers the basics of propellers.


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Do you have any questions for me?  Have I forgot something?  Leave me a comment below.


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