Tutorial: scaling a custom RC Hovercraft


To build a custom RC hovercraft, the first step is to determine the scale of your model and the power it will require.
If you’re new to hovercrafts, I recommend checking out this page — it covers some useful theory to get you started.


Let’s say you want to build an RC hovercraft modeled after a real recreation hovercraft with the following specifications:

Dimensions: 3 meters long, 1.8 meters wide, 1.5 meters high
Total weight: 260 kilograms (180 kg dry weight, 10 kg of fuel, and 70 kg for the pilot)
A single engine with 30 horsepower

1 – Determine the Scale of Your RC Model

To create a compact RC hovercraft, let’s set its length to 50 cm.

Starting from the original length of 3 meters, the scale of the RC model is: 3 meters ÷ 0.5 meters = 6

So, the scale is 1:6. Based on this scale: Width = 1.8 meters ÷ 6 = 30 cm - Height = 1.5 meters ÷ 6 = 25 cm




2 – Calculate the Power Required for Your RC Model

First, convert the engine power from horsepower to watts.

Since 1 horsepower = 736 watts, 30 horsepower = 30 × 736 = 22,080 watts

Next, calculate the cube of the scale factor: 6 × 6 × 6 = 216

Divide the original power by this number to get the model’s required power: 22,080 ÷ 216 = 102 watts




3 – Determine the Maximum Weight of Your RC Model

Similarly, divide the original weight by the cube of the scale factor: 260 kg ÷ 216 ≈ 1.2 kg

This is a relatively heavy weight, allowing you to install two LIPO batteries on your model.



Final specifications for your RC hovercraft:

Dimensions: Length: 50 cm, Width: 30 cm, Height: 25 cm
Maximum weight: 1.2 kilograms
Power: 102 watts



Just for fun, let’s compare these results with the specifications of our Formula 3 model:

Dimensions: Length: 50 cm, Width: 25 cm, Height: 23 cm
Weight: exactly 1 kilogram
Power at maximum speed: 170 watts (measured using a clamp ammeter: 17 amps × 7.2 volts)


Now you can have fun running another set of calculations using Formula 1 hovercraft specifications: 180 horsepower, 3.5 meters long, and 350 kg.