There are plenty of do-it-yourself drone projects on the Internet in this day and age. Some have been made in competition with models made by companies, some in competition against other like-minded technical contestants and some just to see if their ideas of a drone can match or exceed companies in some way, usually in airtime.
There are a few decisions you have to make in order to build a drone:
Building the Frame
Are you interested in building your own drone? If you want to build your own drone, you first have to decide on the type of frame you want to use.
There are drones that have three arms (tri-copters), four arms (quadcopters), six arms (hex copters), and eight arms (octocopters). All of these drones have their arms attached to a single motor.
The second decision you will have to make is the material you want to use for your drone. You can use wood, which is a cheap material and easy to replace when a part is damaged.
The downside to using wood is that the grain has to be free from twists and warps. Carbon fiber is a common option for the DIY hobbyist because it is lightweight and tough.
The downside to using this material is the obstruction of the RF signals you will be using, so you need to be aware how you take care not to block the signals that you will need.
Another issue is the affordability of carbon fiber. It is not the most inexpensive material on the market. Printed Circuit Board (PCB) is a material that can be considered and shares the same type of structure as fiberglass.
Plastic is a good material to use for a drone. Often it is used for the landing gear and covers. G10 is a fiberglass that is sold as a pre-cured sheet and is less expensive than carbon fiber, making it a more desirable material to use.
Aluminum is easy to work with, inexpensive and is easy to find. It is not as light as carbon fiber, but the other attributes may override the weight aspect.
The decision of size is important. You can decide to build a ‘nano’ drone, which can fit in the palm of your hand or decide to build a ‘mega’ drone that needs to be transported on the back of a truck. A good size for a drone to begin such a project is about the size of a sheet of paper or slightly smaller.
Finding the Right Motor
The motor is the main part of the drone. It should give the UAV a constant continuous thrust for a stable lift from the ground when attached to the propellers.
A motor that does not give a continuous thrust will not be stable. An RC motor is an electrical motor made of a magnet (in the bell) and coils of wire that brush (or move) against each other, making a magnetic field, producing electricity.
These motors have a short life span because they wear out quickly. The brushless motor is set up in reverse the brush motor and has a longer lifespan as well as a longer airtime.
The best way to explain the Inrunner motor is to remember that the revolutions occur inside the chamber.
The Outrunner is then the motor that the revolutions occur outside the core. The KV Rating of a motor tells you how fast the motor is able to spin at a certain voltage.
A low KV is good for stable flight, but if you plan on acrobatics from your UAV you will need a high rated KV motor.
Propellers are different from helicopter blades, blades should not be used for UAVs simply because their slim structure and design will not support the UAV.
Propellers on a drone are directly attached to the motor and will spin when the motor is engaged. Smaller propellers on drones are easier to control in speed and are used for acrobatics.
Larger propeller drones are harder to control but have a more stable flight, which makes them more suitable for videos. The types of material that propellers can be made of are similar to the body, but there are a few materials that seem to be used most often.
Plastic is the most popular choice because of the cost. Another reason is the sturdiness of plastic. You can also use wood for propellers. They are sturdy but they can cost due to the complex machining required.
The high-quality material used by UAV enthusiasts is carbon fiber. This material is very hard to break but it will be top dollar to purchase.
Attaching your propellers to your motors may seem simple; you should be aware of and think about ahead of time. No one likes to have to wait to finish a project. Sometimes, not always, propellers come with specialized adapter rings.
It is in your best interest to order these adapter rings for extra security that you will have some, should your propellers not come equipped with any.
If the ‘bore’ of your propeller is too large, you will need these adapters. You can also use a prop saver. This o-ring holds your propeller to the shaft of your motor. It has its drawbacks.
The o-ring can break, it can cause vibrations that could affect the performance of the UAV or the propeller will not sit as low on the shaft of the motor. Another idea you may want to consider is the prop guard.
This will help prevent damage to your propellers in the event of crashes by minimizing damage to the propellers.
The drawbacks of a prop guard are that they will add weight to the AUV, they are not going to work for a major collision and they will most likely add vibration to the AUV that could affect its performance.
The Electronic Speed Controller
The electronic speed control (ESC) controls the flight of the drone. Meaning the ESC controls the direction and speed of the motor. It should also be able to control the highest current that the motors are going to utilize.
The best battery to use for a UAV is the Lithium Polymer (Li-Po). They are pricey but the battery itself has the power needed to execute proper drone lift off. The reasons they are the best
Power means sustainability. In this case, the power that this battery gives off can give your drone a longer length of airtime. The voltage of a battery needs to match the motor, otherwise, there will be problems such as blown motors, or burned out batteries.
The Flight Controller. The flight controller is the brains of the UAV (not to be mixed up with the electronic speed control).
This part includes all of the microprocessors, sensors, and output and input pins. The flight controller makes it possible to operate and navigate your UAV through the air.
Putting the Drone Together
This is the fun part of the project. You know what everything is and what it does, now it is time to put it all together.
Assemble the frame so that the motors will sit at the end of each arm. Make sure that your electronics will fit in the center snugly so that there is nothing that will cause the UAV to vibrate or shift when you get it off the ground, or worse, get tangled up because it was not secured properly.
Connect your USC to each motor and add your propellers securely. Make sure they are snug on the shafts of the motors. Remember to stand back a few feet. A safe distance would probably be four or more feet away.
Remember to try one direction at a time until you are comfortable with how much control you have over your drone. There is no learning curve here, just take your time. You built this drone so there is no hurry to crash it and have to make repairs right away.
Make it hop and fly small distances. You will have it in the air and enjoying a flight in no time at all!