### What is a propeller of drone?

A propeller is a blade. When it is installed on a drone, the lift generated by rapid rotation will bring the drone into the air. The propeller is one of the power systems of the drone. It is generally made of plastic, and some high-end propellers are made of carbon fiber.

In general, hard and light propellers are better than heavy and curved ones. Some drones are equipped with a special propeller, and you can press it gently into the drone. This is especially useful for novices, because novices may not know the proper torque when tightening the propellers.

### What does the propeller model mean?

Propeller has its mode. For example: 1045, the first two digits represent the diameter of the propeller (in inches, 1 inch = 25.4mm), and the last two digits represent the pitch of the propeller.

For example, the 1045 paddle is 10 inches in length (10 * 2.54 = 25.4cm), and the pitch is 4.5mm; the 1245 paddle is equivalent, and the 8045 paddle is 8 inches (8 * 2.54 = 20.32cm) in length, and the pitch is 4.5mm; other analogies

### How to distinguish between CCW and CW paddles?

The Propeller Direction: CW and CCW

When installing, be sure to remember that regardless of the CCW and CW paddles, the worded side is upwards (the rounded side of the blades must be consistent with the motor rotation direction).

You can also use the lettering on the blades to distinguish between CCW and CW propellers, for example: the words L and R are engraved on the blades, “L” stands for CW paddle, and “R” stands for CCW paddle. Of course, different propeller manufacturers use lettering to distinguish CCW and CW propellers.

### Why do we need CCW and CW paddles?

In order to offset the spin of the propeller in four-axis flight, the rotation direction of the separated propellers is different (as shown below), so CCW and CW propellers are required.

### Choose a two-blade or three-blade paddle?

As the name suggests, a two-bladed paddle is a paddle with two blade , and a three-bladed paddle is three. Generally, two-bladed paddles are commonly used for quad, and three-bladed paddles can be used for small-size quad. Propellers with the same diameter and the same pitch of three blades are significantly more efficient than those of two blades.

In addition, the efficiency of the asymmetrically arranged propeller is higher than that of the symmetrically arranged propeller. The maximum number of blades is 7 blades, which is a relatively advanced propeller. On models above x450, three-bladed propellers are rarely used, because the larger the size, the more difficult it is for the blades of the three-bladed propeller to perform dynamic balancing.

### How to calculate the required propeller diameter?

The diameter of the propeller is determined by the straight line distance between two adjacent axes, which is the distance of the AB line in the figure, and the distance of the AB line is just the maximum diameter of the propeller.

To find the distance of AB in a triangle, use the cosine theorem.

AB² = AC² + BC²-2AC * BC cosβ

Example: A quad frame with a wheelbase of 450mm.

AB² = AC² + BC²-2AC * BC cosβ

AB² = 225² + 225²-2x225x225x0

AB² = 318.20mm = 12.5 inches

Therefore, the maximum propeller diameter obtained is 12.5 inches.

The actual propeller diameter cannot be exactly equal to this value, otherwise the two propellers will fight.

Most of the propeller diameter specifications are integers. It can be known that the maximum propeller diameter supported by this rack can be selected to 12 inches.

If it is to obtain the maximum flight time, try to use the largest diameter propeller supported by the frame.

### Tips

Although the propeller is durable, it is also fragile, so do not place it in a place where it is easily damaged.