Monthly Archives: March 2013

Tech terms

Pitch – the theoretical distance in inches that a propeller moves forward in one revolution. Think of a screw in wood. If you increase the angle of the threads, it will move further into the wood in one turn. Diameter – the diameter in inches of the circle that the blade tips will cut. Or, the distance […]

Should I go from a three blade to a four blade prop?

If you look at a propeller from behind, and visualize a circle that the blade tips would draw, you will see that the blade of a 3 blade prop covers about 50 -55% of the circle. (This is called diameter area ratio, or DAR). You can add thrust within this drive circle by increasing that […]

Do composite and aluminum props flex?

Of course! All propellers flex. What is often missed is that flex is a good characteristic. For example, if a prop flexed under the load of acceleration, it would actually be reducing its pitch, which in turn would produce a faster acceleration. A problem would occur only if the prop failed to return to its […]