Have you been trying to shop for propellers - either online or at a hobby shop - and got confused of the numbering used to denote the size of the propellers? You see things like "10 x 4.5 CW", or "8055 CCW".
What do these numbers mean?
It's actually quite simple once you figure it out.
The first number denotes the diameter of the prop (length from tip-to-tip).
The second number denotes the pitch of the prop. Here, the pitch is denoted as a length, not a angle. Let's see how that works.
Let's take a 10 x 4.5 prop as an example:
This maybe denoted by either "10 x 4.5" or "1045". Both these numbering schemes means the same thing. e.g. 8055 = 8 x 5.5
The following diagram illustrates how the two numbers work.
Now, it should be noted that the pitch number is the distance the propeller moves in an 'ideal' scenario. On a practical scenario, due to the characteristics of air, and various other factors, the actual distance a prop moves when rotating will be different than what the pitch number denotes.
A higher pitch prop will give a lot of acceleration to your aircraft, and will give a higher top speed. But it would put a lot of load on your motor (or engine). You should consider the load your motor can handle, power consumption, and the heat generation when going for a higher pitch prop.
A lower pitch prop would be slower. But it would put less strain on your motors.
What about the 'CW' and 'CCW' denotation?
CW is 'Clockwise', which means the prop will move forward when rotated clockwise.
CCW is 'Counterclockwise', The prop will move forward when rotated counterclockwise.
Hope this clears out any confusion you had when buying props.
Related posts:
What is the meaning of the numbers on Brushless Motors?
What do these numbers mean?
 |
| A 8 x 4.5 CW and CCW Propeller Set |
It's actually quite simple once you figure it out.
The first number denotes the diameter of the prop (length from tip-to-tip).
The second number denotes the pitch of the prop. Here, the pitch is denoted as a length, not a angle. Let's see how that works.
Let's take a 10 x 4.5 prop as an example:
- The diameter of the prop would be 10 inches.
- The pitch of the prop would be 4.5 inches. It means, on an ideal situation, one rotation of the prop would pull it 4.5 inches forward.
This maybe denoted by either "10 x 4.5" or "1045". Both these numbering schemes means the same thing. e.g. 8055 = 8 x 5.5
The following diagram illustrates how the two numbers work.
 |
| The length and pitch of a prop |
Now, it should be noted that the pitch number is the distance the propeller moves in an 'ideal' scenario. On a practical scenario, due to the characteristics of air, and various other factors, the actual distance a prop moves when rotating will be different than what the pitch number denotes.
A higher pitch prop will give a lot of acceleration to your aircraft, and will give a higher top speed. But it would put a lot of load on your motor (or engine). You should consider the load your motor can handle, power consumption, and the heat generation when going for a higher pitch prop.
A lower pitch prop would be slower. But it would put less strain on your motors.
What about the 'CW' and 'CCW' denotation?
CW is 'Clockwise', which means the prop will move forward when rotated clockwise.
CCW is 'Counterclockwise', The prop will move forward when rotated counterclockwise.
Hope this clears out any confusion you had when buying props.
Related posts:
What is the meaning of the numbers on Brushless Motors?
Thanks for this. I've been looking for a clear explanation of exactly what the "pitch" designation is and you've provided it perfectly.
ReplyDelete