Powerful Automatic Tennis ball launcher – 30-35 meters!

• Complete project folder with .STL files, parts list, wiring diagram, build instructions and Arduino code

• Project electronic cost estimate: €85 or $95

Designed and printed this powerful and automatic tennis ball launcher for our overly active German Shepherd. Because he has enough space to run around here it could be quite a bit of a powerful ball launcher. And that's what it has become! The GIF in the Pictures shows the first test. (Without housing still) That was about 10-12 meters but after a few minor adjustments it now shoots consistently about 30-35 meters. Parts list with internet links, electrical diagrams and Arduino code are all in the folder. If you still run into problems during the build, you can always me via my e-mail. I added my email address in the top line of the Arduino code.

• Housing:

I made the housing from 5mm white foam board in combination with white duct tape. Cheap, easy to work with, light, strong and also a neat finish! The .STEP file of the housing is also in the folder if you need my dimensions.

• Tennis Ball launcher Parts list

Electronics:
1x MG996R Servo
1x Arduino Nano
1x XT60 connector set
2x Brushless motor 5010 – 360KV
2x ESC 30A, 4S

Bearings:
2x Bearing 625ZZ

Screws:
11x Screw M3x10mm
12x Screw M3x20mm
8x Screw M3x30mm
8x Screw M4x20mm
2x Screw M5x25mm
24x Screw M6x30mm

Threaded inserts:
31x M3 brass threaded insert
8x M4 brass threaded Insert

Materials for housing (Optional):
2x Foamboard 5mm, 1000x700mm
1x Roll Duct-tape white, width 50mm

Arduino Code:

#include

// Define the pins for the ESCs and ball stopper servo
const int esc1Pin = 9;
const int esc2Pin = 10;
const int servoPin = 6;
const int sensorPin = 7;

// Create Servo objects for the ESCs and ball stopper
Servo esc1;
Servo esc2;
Servo ballStopper;

void setup() {
// Attach the ESCs and servo to the corresponding pins
esc1.attach(esc1Pin);
esc2.attach(esc2Pin);
ballStopper.attach(servoPin);

// Initialize the ball stopper servo to the initial position
ballStopper.write(0); // Adjust this value as needed to match your setup

// Initialize Serial Monitor for debugging
Serial.begin(9600);

// Setup the sensor pin
pinMode(sensorPin, INPUT);
}

void loop() {
// Read the sensor value
int sensorValue = digitalRead(sensorPin);

// If the sensor is triggered, launch the ball
if (sensorValue == HIGH) {
// Generate a random delay between 5 and 15 seconds
int randomDelay = random(5000, 15001);
delay(randomDelay);

// Launch the ball after the delay
launchBall();

}

// Short delay before the next loop iteration
delay(100);
}

void launchBall() {
// Start the flywheel motors
esc1.writeMicroseconds(2000); // Adjust this value for your ESCs
esc2.writeMicroseconds(2000); // Adjust this value for your ESCs

// Wait for the flywheels to reach full speed
delay(2000); // Adjust this delay as needed for your setup

// Release the ball using the ball stopper servo
ballStopper.write(90); // Adjust this value to release the ball
delay(500); // Wait for the ball to launch
ballStopper.write(0); // Reset the ball stopper

// Stop the flywheel motors
esc1.writeMicroseconds(1000); // Adjust this value for your ESCs
esc2.writeMicroseconds(1000); // Adjust this value for your ESCs
}

I recommend printing all parts with a 0.8mm nozzle, at least 3 walls, 3 top layers, 3 bottom layers and 20% cubic infill. If you want to print with a 0.4mm nozzle, stick to 6 walls, 5 bottom layers, 6 top layers and 30% cubic infill.