It is not possible to control the speeds of the drone unless you make use of speed controllers. The controllers facilitate you to control the current of the motors plus the voltage. That is how the controllers manage the drone speeds.
The first concern when you float your drone in the air, is the ability to control the speeds. It determines how you move the drone right, left, back or front.
It is important for a drone to use powerful motors. Brushless DC motors are used in the lightweight, powerful, cheap drones. However, the small drones should use small DC gear motors.
There are basic factors that affect the efficiency and performance of a motor, and that includes its design features, construction, among other things.
How do I choose a drone motor?
What is the size and weight of the drone you want to build? Do you want to use it for security ?That will help you to choose the right type of motor for the drone. To start off successfully, determine the frame you are going to use. It will help you restrict the size of the motor or propeller you will use.
There are some frames that you will buy that will come with the recommendations of the motors you can use, and what to look for. Below are some of the things to consider:
- The ratio of thrust to weight
First check the weight of the drone. Ensure that your drones can give 50% more thrust than the weight of your drone. The total weight should include all the components of the quadcopter. Calculate the weight of the frame, motors, ESC, LiPo battery, FC, GoPro, among others.
You do not necessarily have to work with accurate figures, estimates will do. An overestimate would be okay, but be careful not to underestimate. An underestimate would mean that the drone would struggle to take off. Above the total estimated weight that you come up with, add extra 10-20 grams. It will help to compensate for the weight of stuff such as electrical wires, zip ties and buzzer among others.
There is a rule of the thumb that you should work with as you calculate the weight to thrust ratio. Ensure that the maximum thrust that all the motors produce, is in the minimum, double of the total calculated weight of the drone. Remember to have more than the required thrust.
If you are flying a drone that requires higher speeds, for example a racing drone, you will need to work with a higher power to weight ratio.
That explains why it is possible to come across ratios such 13:1, or 10:1. If your drone is meant for Acro flying, the recommended thrust to weight ratio is 5:1.
The weight to thrust calculation is not something that one should overlook. It is the factor that determines whether your drone has enough thrust that can enable the drone to maneuver in strong winds and aggressive flights.
The recommendation is to have a drone with 2:1 ratio, in terms of thrust to weight. The idea is to have a drone that can take extra weight for bigger batteries when you need to fly the drone much longer.
It is critical to know or determine how efficient the motor you choose for your drone will be efficient. To do this, divide the thrust, by the power used and have that in watts, or g/w. The higher the figure you get, the more efficient that motor will be.
The bigger the g/w answer is, the higher your copter will fly. Some motors will give you up to above 18, and that is a high level of efficiency.
When you have several motors with you, choose the most efficient of them, but as you may notice, the most efficient will also be the most expensive.
If you are however focusing on a motor for small copters, you may need to concentrate more on one that has high rpm. For example, you may notice a motor for a mini-quad has a motor with relatively poor efficiency.
Experts suggest that you get a motor whose efficiency level is about 7 or above that.
This is a measure of how capable a motor is, to shift between RPM values. The ability to shift is critical, because it what measures how responsive the drone will be in the air.
High torque value results to snappy drone response, because the higher the torque value, the faster it accepts the changes.
Higher torque value will enable the motor to run much heavier props, but the downside is that it will suck more current.
If you want to prop heavier propeller on a lower torque value, the motor will not successfully achieve This will eventually mean that your motor will not generate sufficient torque needed for spinning.
One disadvantage of connecting to motors that have high torque value is that they generate more oscillations which makes them very hard to tune.
- Pole count
There are two types of motors when you need to consider the pole count. The first type is the one that has a higher pole count. This type has two characteristics-it offers a higher torque value, while at the same time it demands a high voltage for its operations. Its RPM is also lower.
Experts suggest that if you go with the first category of motors, you then work with larger blades.
The second category has a lower pole count but produces a higher RPM. This goes well with smaller blades and serves where a smaller lift from the ground is suitable.
Why are brushless motors better for drones?
There are two types of motors when the consideration is the brushes the motors use: Brushed and brushless motors. The major difference between the two is the brush. What does that entail?
A brushless electric motor means that the motors are synchronically powered motors directly by electric power, with the use of an inverter.
On the other hand, a brushed motor means that the electric motor is internally commutated, and operates from a direct source of power.
What makes the brushless motor significant is because it does not require any physical commutator. This is what makes it a popular choice for aircrafts, computers and robotics.
The other advantages of the brushless motors include:
- Their torque to weight ratio is higher
- They have a higher efficiency
- Their operational and mechanical noise is much less
- Their lifespan is much longer, because they do not have erosion between the brush and the commutator.
- They are more reliable and require lesser maintenance.
- They eliminate ionization from the commutator.
- They almost completely eliminate the EMI, Electromagnetic interference.
How much does a drone motor cost
The price ranges of different drones depend on various factors.
Each variety of drone will cost you differently. If you are trying out the experience of flying out a drone, you can pick among the cheaper options.
If your option is a drone that comes with better features such a good camera, the cost will definitely be higher.
If you decide to make the drone by yourself, it will help you cut on the purchasing costs.
The cheapest drones are the types that fall under the toy drones. Those come at the range of $30 and you can have some in this category that come with a HD camera at the range of $50, and an example is Syma X5C.
You can also get the smallest drone in the world for only $45.
There are those copters that have better features and these will come at a higher price. An example is the Parrot Bebop which ranges about $400. It has a great efficiency and offers a smooth flight.
The DJ1Phantom version will provide a better aerial view when you need to use the drone for photography, and it will cost about $500.
Cheerson CX20 has a great efficient GoPro mount and you will get that at about $200.
The last category is the type of drones that professionals will opt for. The prices in this category are much higher.
The Walkera Tali is a great choice for those who are professional photographers.
You will get it at the range of $800 to $1400, and if you use it, you will experience the beauty of first person view from the higher ground.
It works for the keen enthusiastic person.
Another version of an excellent copter one cannot skip in that category is the Spreading Wings version. No copter gives you a smoother or a better experience with your flight as this version. This copter will cost you about $1500.
If you an enthusiastic and desire a copter with a 4k video camera, the DJ1T600 will serve you excellently. You will get it for about $3000.
If the feature you most desire is a copter that offers great efficiency, then DJ1Matrice will give you exactly that. You will get it for about $3300
When all is done, choose the motor that serves you well, and get the drone that meets your need.