When it comes to building a multicopter, there are other components that are important to ensure a successful flight! By focusing on each key component and exploring the basic tips below, you’re going to have a much better chance of making that first flight a success!
You need to choose the right prop in-line with the manufacturer’s specifications sheet for your motors. This is to ensure you’re operating the multicopter most efficiently. If your prop is smaller than the manufacturer’s guidelines, it will affect performance; too big or too much pitch, you may burn the ESCs and/or motors out.
A good motor manufacturer will provide you with a data sheet outlining thrust values on different props and voltage ratings. This will assist you in making the right choice when it comes to not only choosing your props; the right battery too!
Additionally, it is important that you learn how to balance a prop because this is the main source of vibration for multicopters. Vibration can cause unpredictable flying characteristics and loss of control in some instances. It can also reduce the lifespan of your motors and decrease efficiency.
You will notice that there are many props to choose from including forms and materials. In addition, there is a great deal of information that can be discussed on this topic – we will stick to the basics to get you started.
The length of a prop is important because it’s one of the contributing factors to generating lift. The length is determined by measuring from one end of the prop to the other in total for two blade props. For three and four blade props, the length is determined by doubling your measurement of a single blade.
Can your selected prop fit on your multicopter without hitting other props or the airframe? Most airframes come with a recommendation as to how large of a prop can fit.
It’s important to choose the right prop center diameter or ensure your prop comes with spacers allowing it to fit your motor.
The pitch of a prop is the second determining factor when it comes to generating lift. You need to make sure you have the right pitch in-line with motor manufacturer’s guidelines to ensure sufficient lift is generated in the most economical way.
You will notice most props ship in pairs of Clockwise (CW) and Counter-Clockwise (CCW). This is particularly important to multicopters because some motors spin in opposite directions which allows the multicopter to use centrifugal force to turn the multicopter on the yaw axis.
Propellers on multicopters are mostly made of plastic or carbon fibre. We’re not going into much detail on this as both have their benefits. You will notice that there is a significant price difference between the two.
Carbon fibre is lighter and more rigid than plastic. This can provide a much smoother flight. However, it’s quite costly.
Plastic is much more affordable but generally tends to be more work to balance a prop, given the manufacturing process*. When starting out, you will crash more often so a plastic prop is perfectly fine!
Airframes come in all shapes and sizes. After conducting research, based on your overall objective, you will find a better idea as to how big the multirotor will be. 350 size (350mm from motor centre to motor centre) through to 550 size is most common.
Written by Thomas