Remote-control Racing Hovercraft

• Overview

The giant, powerful hovercraft in the film Red Bronx have excited us for a long time. Recently, our university held a hovercraft competition. We made a remote control hovercraft and won the first place in the Time Trial. Our hovercraft is stable but flexible, with low cost and energy consumption. Below is a step-by-step instructions. With some basic Arduino knowledge, you can make a racing hovercraft within one day!

• Difficulty level

★★★★☆

• Age: 15 and above

• Time requirement

6 hours (without preparing the materials)

• Total cost

About $80

• Materials needed

See step 1

Get Materials

I.Electronic Components.

Arduino board (UNO)

Battery (7.4V)

Brush Motor*2 (Type 280 and 380) (22RMB and 30RMB)

Electronic Speed Controller (ESC) (45RMB)

Servo (MG90S) (20RMB)

Conversion Lines (15RMB and 10RMB)

Dupont Lines (4.1RMB and 5.3RMB)

Remote control (2.4GHz) and receiver (168RMB)

II. Mechanical Components.

Polystyrene blocks

Propeller*2 (5RMB and 4RMB)

Rudder pin *2 (0.6RMB*2)

Steering tie rod *2 (2RMB*2)

Foam glue (3.5RMB)

Insulating tape (3RMB)

& Double faced adhesive tape (1RMB)

Knife

Bench with resistance wire

Electric iron

• See the diagrams.

• Draw on the polystyrene blocks with a mark pen.

★Warning: Do NOT change the blocks’ shapes.

• Draw the 4 bottom boards.

The radius of the circles is 1 mm.

Block #1 (25mm)

Block #2 (15mm)

Block #3 and #4 (5mm)

Block #5 (15mm)

The circle’s size should be slightly larger than that of the lift propeller.

Block #6

The circle’s size is the same as that of the lift propeller.

• Draw the fan housing.

Block #7 (50mm)

The circle’s size is the same as that of the thrust propeller.

Block #8 (25mm)

The circle’s size is the same as that of the thrust propeller.

The rectangle’s size depends on the servo.

• Draw the 2 rudders.

Cut
the blocks

Block #9 and #10 (2mm)

• Set the bench and the resistance wire.

• Heat the resistance wire for 5 seconds.

• Place the block on the bench.

Push the block against the resistance wire to cut a rough contour.

• Cut along the lines that you have drawn.

Tips:

• Cut a straight line.

Fix a steel ruler along the line.

• Cut a part inside.

Cut a small hole inside the part to cut out.

Reset the resistance wire through the hole.

• Cut a circle.

Fix the center of the circle on the bench.

Rotate the block.

★Warning:

• Do NOT touch the heated resistance wire. It will burn your skin.

• Do NOT make the resistance wire too hot. It may damage the blocks.

• Wear a respirator. The block-cutting process produces poisonous gas.

• Stick block #2 inside block #1.

• Stick block #4 onto block #3.

• Stick block #3 onto block #2.

• Draw on a plastic film.

• Cut the piece out with a knife.

• Stick the film’s inward edge to block #2 with foam glue.

• Seal the joint of the film’s outward edge and the block #1 with hot melt glue.

•Fix the smaller motor (280) onto the smaller motor bracket.

• Fix the smaller thrust propeller onto the motor. (see step 9 III)

• Stick the motor bracket to block #6.

• Stick block #6 to block #5.

The lift propeller is in the hole of block #5.

• Power the lift propeller with the battery.

• Observe whether the shape of the air cushion is level and smooth.

• Feel whether air leaks at the joints of the films and the blocks.

★ Warning: Repeat step 5 and 6 until the hovercraft passes the air-tightness test. The hovercraft cannot function with air leakage.

• Fix block #9 and #10 onto the 2 rudder pins.

• Connect the two rudder pins with a rod.

• Connect one end of the other rod to the right rudder pin.

• Press the rudder into the gaps of block #7.

• Stick the servo onto block #8.

• Fix the larger motor (380) onto the motor bracket.

• Fix the thrust propeller onto the motor.

• Stick the motor bracket into block 8# with foam glue.

• Stick block #7 to #8.

• Connect the other end of the rod to the servo.

• Stick block #7 and #8 onto block #5.

• Install the Arduino software.

• Connect your Arduino board with your computer with the USB cable. Operate the software on your computer.

• A mark “check” shows up when you connect the Arduino board to your computer. Check whether you have installed the corresponding drive on your computer in a correct way.

• Upload your codes to the Arduino board.

• If you have uploaded the codes, the software will give the remark: “upload successfully”. If not try again.

The codes to control the hovercraft :

#include <Servo.h>

Servo myservo;

Servo rudderservo;

int ppm1 = 2;

int ppm2 = 3;

float spd,dir;

unsigned long rc1_PulseStartTicks,rc2_PulseStartTicks;

volatile int rc1_val, rc2_val;

void setup() {

Serial.begin(9600);

//PPM inputs from RC receiver

pinMode(ppm1, INPUT);

pinMode(ppm2, INPUT);

attachInterrupt(0, rc1, CHANGE);

attachInterrupt(1, rc2, CHANGE);

myservo.attach(5);

rudderservo.attach(6);

rudderservo.write(90);

}

void rc1()

{

// did the pin change to high or low?

if (digitalRead( ppm1 ) == HIGH)

rc1_PulseStartTicks = micros(); // store the current micros() value

else

rc1_val = micros() - rc1_PulseStartTicks;

}

void rc2()

{

// did the pin change to high or low?

if (digitalRead( ppm2 ) == HIGH)

rc2_PulseStartTicks = micros();

else

rc2_val = micros() - rc2_PulseStartTicks;

}

void loop() {

spd = map(rc1_val, 956, 1876, 10, 180);

dir= map(rc2_val, 1040, 1912, 60, 120);

Serial.print("channel 1: ");

Serial.print(rc1_val);

Serial.print(" ");

Serial.println(spd);

Serial.print(" ");

Serial.print("channel 2: ");

Serial.println(rc2_val);

Serial.println(dir);

Serial.println();

myservo.write(spd);

rudderservo.write(dir);

}

• Weld the 2 motors’ positive wires together, and weld their negative wires together.

• Connect the battery to the ESC.

• Connect the servo, ESC, and receiver to the Arduino board with Dupont lines.

★ Warning: Wrap all the joint points with the insulating tape.

• Connect the ESC to pin 5.

• Connect the servo to pin 6.

• Connect the receiver’s channel 1 to pin 2, and channel 3 to pin 3.

• Fix the ESC, the Arduino board, and the receiver onto block #5.

• Fix the battery onto block #6.

• Power the ESC and Arduino with 2 conversion lines

•Turn on the remote control.

•Power the hovercraft with the battery.

• Adjust the left lever to the lowest position to activate the receiver.

• Practice and have fun!