Quadcopter Design – The Basics



Quad copter is not an unknown form of technology anymore. Almost everyone who has an interest in technology knows what it is and what are its benefits.

In this blog post, you will learn:

Quadcopter Design

quadcopter design

If you happen to be someone who is immensely interested in quadcopter design, then know that it takes a lot of time and effort and is not an easy job in any way. If you get afraid of the programming and the mathematics it includes, but carry a good budget with you, then you can go for a pre-built kit. It’s usually assembled in minutes and is then ready to fly. But you are missing out on the fun that comes with the development of a quadcopter.

A bit of introduction to what quadcopters are: They are symmetrical vehicles that come with four rotor (equally sized) placed at the end of four equal sized rods. The use of the multiple rotors allows the greater thrust for the craft.


1- It is an unpiloted aircraft that is flown autonomously depending on the pre-programmed flight plans.

2- Used in numerous civil applications, for instance: aerial photography.

Purpose And Goals

1- Quadcopter have been a great assistant for the unmanned flights all across the globe in terms of hardware and software.

2- The importance of the unmanned flights is very crucial when it comes to the insurgencies at the time. Also, the VTOL (Vertical Take-off and Landing) crafts are attracting the whole world in terms of their vertical flights.

3- Quadcopters are used for military applications in the missions that pose danger to manned aircrafts.

So we can summarize the overall goals in these points:

  1.       The Achievement of Autonomous Take off and Landing.
  2.       Streamline the Mechanical Construction/ Weight
  3.       Use of continuous updated technology.

Having briefly described the Quadcopter’s applications and purpose, we now move on to the basic building of the quadcopter:

How To Build A Quadcopter – Choosing Hardware

hardware quadcopter

QuadCopter is basically a helicopter with four rotors, which also makes it called ‘Quadrotor’ . Its unique design allows a stable firm platform making it ideal for aerial photography or tasks such as surveillance and for research like UAV. The size of Quadcopters vary from as small as a CD to something like one meter in width.
Usually, the regular helicopters we see have a one big rotor to cover for the lifting power coupled with a tail rotor to cover the aerodynamic torque that’s generated by the bigger rotor. But for the quadrotor, the all 4 rotors work together in order to produce an upward thrust where each rotor bears the 1/4 of the weight. So basically, the movement of the quadcopter is actually controlled by the thrusts produced by each rotor.

Digging In The Hardware:

Rotors are aligned in square position i.e two positioned on opposite sides are for clockwise direction while the other two work for the anti-clockwise direction. So the question is, why not they all are in the same direction? Because if they would be, the craft would work like a regular helicopter without the tail rotor (in terms of spinning). Yaw is induced by unbalanced aerodynamic torques.
Here’s the trick behind the quadcopter’s same direction flying:

The aerodynamic torque that belongs to the first rotors pair cancels out the torque the second pair produced (rotating in the opposite direction), so this is how the four rotors apply equal thrust resulting in the same direction. 

How It Maintains Balance

Quadcopter maintains balance by continuously acquiring measurements from sensors and adjusting each rotor’s speed to maintain the body level; these measurements are calculated by a control system embedded in.
There are 4 controllable degrees of freedom:

  1. Yaw
  2. Roll
  3. Pitch
  4. Altitude

The above mentioned degrees of freedom are controlled through the adjustment of each rotor’s thrusts.

  • Yaw: Yaw is controlled by increasing the regular rotating motors’ speed.
  •  Roll: Left and Right Tilt. Roll is controlled usually by increasing one motor’s speed while lowering the speed on the opposite one.
  • Pitch: Up and Down Movement Just Like Nodding. Pitch is controlled using the second set of motors but in the way same as roll.

You can understand this in a way that to roll or pitch, we decrease the thrust on one rotor while increasing the other rotor’s equal amount speed. This way, the quadcopter tilts, and when it does so, it causes the force vector to split in horizontal and vertical component.

Latest Quadcopters in 2016:

There are a lot of quadcopters already in the market, but we have compiled the latest ones here:

1- The Eyes Drone 954 Quadcopter

2- MJX X400

3- TRC01

4- DJI Phantom 3

5- Mini Drone 4CH

So now we come to the end of design basics. And we are sure you would definitely want to read our Complete drone guide 2016!

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