# How does prop pitch affect RPM?

Table of Contents

## How does prop pitch affect RPM?

Increasing the pitch will decrease engine rpms and decreasing the pitch will increase engine rpms. As a general rule, a two-inch increase in pitch will result in a reduction of 300 to 400 rpm. Conversely, a two-inch decrease in pitch will result in an increase of 300 to 400 rpm.

## How do I choose a motor and prop for my RC plane?

The kv of your motor is the number of revolutions per minute it will spin per volt. The lower the kv, the stronger the motor and as a result, you will want a larger propeller for maximum thrust. Often slower motors will also result in slower flying planes, a big plus for your first hobby grade rc plane.

**What is the rpm of a plane propeller?**

An airplane׳s engines often run faster than its propellers. For example, on one airplane, the most efficient engine speed is 3,000 RPM, while the most efficient propeller speed is about 1,500 RPM.

**What pitch prop is faster?**

The lower the prop pitch, the better your hole-shot. However, this comes at a price: top speed. The lower pitch makes the engine reach maximum rpm at slower speeds. Conversely, a higher pitch will deliver greater top speeds, but slower acceleration.

### How do you size a RC plane motor?

Electric motor power is stated in watts. 750 watts = 1 horsepower. An easy way to estimate power needs for RC hobby applications is to use 100 watts per pound for sport flying, 150 for aggressive aerobatics, 200 watts per pound for 3D flying.

### How do you calculate propeller RPM?

To convert feet per second to MPH multiply by 0.681818. If you have a propeller speed reduction unit (PSRU) divide your gear ratio (i.e. 2.58) into the maximum engine RPM (i.e. 6800 rpm) to determine your propeller RPM (i.e. 2636 propeller RPM).

**How does propeller pitch affect thrust?**

In general, a high-pitch propeller produces more thrust, torque, and power for a given advanced ratio compared to a low-pitch propeller. Increasing propeller pitch also increased the range of the propeller region, i.e., the large region of positive thrust and torque.

**Does prop diameter affect RPM?**

A prop’s two dimensions each affect performance in different ways. For every inch of change in prop diameter the RPM varies by about 500 RPMs (up or down) and every inch of pitch changes the RPM by approximately 150 to 200 RPM.

#### How much thrust does an RC plane need?

For example if a particular airplane weighs 50 ozs and has a lift to drag ratio of 20:1 (L/D of the whole airplane) the minimum thrust required for that airplane to remain flying is only 2.5ozs (5% of the weight). A 350 ton Boeing 747 requires less than 10% of its weight in thrust to maintain cruise speed.