Building a Crane System with an Arduino and TT DC Motor

Are you working on an Arduino project involving DC motors? Whether you're building a crane system, a robotic arm, or a conveyor belt, selecting the right motor is critical for success. One of the biggest challenges in motor selection is determining the required torque and power to ensure your motor operates efficiently and meets your application's requirements.

Here, we’ll walk you through how to calculate torque and power for your DC motor using a web-based DC Motor Calculator. We’ll also explain the equations used, provide practical examples, and show how you can integrate these calculations into your Arduino projects. By the end of this article, you’ll have all the tools you need to design efficient motor-driven systems.

Why Use a DC Motor Calculator?

When designing a motor-driven system, it’s essential to calculate parameters like torque , power , and efficiency to ensure the motor can handle the load. Without proper calculations, you risk underpowering your system or damaging your motor. Our DC Motor Torque and Power Calculator simplifies this process by allowing you to input key parameters such as:

• Load weight
• Desired speed
• Wheel radius
• Efficiency
• Voltage and current
• Gear ratio
• Friction coefficient

The calculator outputs the required torque and power, helping you select the right motor and optimize its performance.

Equations Used in the Calculator

The calculator uses two fundamental equations to determine torque and power:

1. Torque (Nm):

Where:

• $m$: Mass of the load (kg)
• $g$: Acceleration due to gravity ($9.81{\text{m/s}}^2$)
• $r$: Radius of the wheel or pulley (m)
• $\eta$: System efficiency (e.g., 0.8 for 80%)

2. Power (W):

Where:

• $\tau$: Torque (Nm)
• $\omega$: Angular velocity ($\text{rad/s}$)

Angular velocity can be calculated as:

These equations form the backbone of the calculator, ensuring accurate results for your motor requirements.

Example: Building a Crane System with an Arduino and TT DC Motor

Let’s say you want to build a crane system to lift small objects (e.g., a 200g weight) using a TT DC motor (3–6V) . The motor will drive a wheel (6.5 cm in diameter) attached to the crane’s pulley system. See the circuit diagram below.

Here’s how you can use the DC Motor Calculator to determine the necessary parameters. See the guide L298N motor driver with Arduino.

Step 1: Define Your Inputs

Before using the calculator, gather the necessary inputs:

1. Load Weight :

   • Object weight = 200g = 0.2 kg

2. Desired Speed :

   • Let’s assume the crane should lift the object at a speed of 0.1 m/s.

3. Wheel Radius :

   • Wheel diameter = 6.5 cm → Radius = 6.5 / 2 = 3.25 cm = 0.0325 m

4. Efficiency :

   • Assume the system efficiency is 80% (0.8).

5. Voltage and Current :

   • TT DC motor operates at 3–6V. Let’s assume 5V.
   • Typical stall current for a TT motor = 0.5A.

6. Gear Ratio :

   • If you’re using a gearbox, let’s assume a gear ratio of 1:50.

7. Friction Coefficient :

   • Assume a friction coefficient of 0.1 for simplicity.

Step 2: Perform Calculations

Using the inputs above, let’s calculate the required torque and power.

Torque Calculation

Substitute the values:

Power Calculation

First, calculate angular velocity:

Now calculate power:

Step 3: Use the DC Motor Calculator

Input the following values into the calculator:

• Load Weight: 0.2 kg
• Desired Speed: 0.1 m/s
• Wheel Radius: 0.0325 m
• Efficiency: 80%
• Voltage: 5V
• Current: 0.5A
• Gear Ratio: 1:50
• Friction Coefficient: 0.1

The calculator will output:

• Required Torque : ~0.08 Nm
• Required Power : ~0.25 Watts

Step 4: Integrate with Arduino

To control the motor, you can use an Arduino with a 10k potentiometer to adjust the speed dynamically. The potentiometer provides a PWM signal to the motor driver, allowing you to vary the motor speed(see controlling DC motor using PWM.). Additionally, you can add a push button to toggle the motor on and off.

Here’s a snippet of the Arduino code: 

// Pin Definitions
const int potPin = A0;      // Analog pin for the 10k POT
const int buttonPin = 2;    // Digital pin for the push button
const int in1 = 8;         // L298N IN1
const int in2 = 9;         // L298N IN2
const int ena = 10;        // L298N ENA (PWM)

// Variables
bool motorState = false;   // Tracks whether the motor is on or off
int lastButtonState = HIGH; // Previous state of the button (HIGH due to pull-up)
unsigned long lastDebounceTime = 0; // For debouncing
const unsigned long debounceDelay = 50; // Debounce delay

void setup() {
  // Set pin modes
  pinMode(potPin, INPUT);
  pinMode(buttonPin, INPUT_PULLUP); // Enable internal pull-up resistor
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(ena, OUTPUT);

  // Initial motor direction (forward)
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);

  // Start with the motor off
  digitalWrite(ena, LOW);
}

void loop() {
  // Read the button state
  int buttonState = digitalRead(buttonPin);

  // Debounce the button
  if (buttonState == LOW && lastButtonState == HIGH) { // LOW means button is pressed
    if ((millis() - lastDebounceTime) > debounceDelay) {
      // Toggle the motor state
      motorState = !motorState;
      lastDebounceTime = millis();
    }
  }

  // Update the last button state
  lastButtonState = buttonState;

  // Control the motor based on its state
  if (motorState) {
    // Read the POT value (0–1023)
    int potValue = analogRead(potPin);

    // Map the POT value to PWM range (0–255)
    int pwmValue = map(potValue, 0, 1023, 0, 255);

    // Apply the PWM signal to the motor
    analogWrite(ena, pwmValue);

    // Optional: Print values to Serial Monitor for debugging
    Serial.begin(9600);
    Serial.print("POT Value: ");
    Serial.print(potValue);
    Serial.print(" | PWM Value: ");
    Serial.println(pwmValue);
  } else {
    // Turn off the motor
    analogWrite(ena, 0);
  }

  delay(100); // Small delay for stability
}

This crane system demonstrates how to apply theoretical calculations to real-world projects. By using the DC Motor Calculator , you can save time and resources while ensuring your motor operates within safe limits. Whether you’re building a robotic arm, a conveyor belt, or a custom crane, this tool is invaluable for Arduino enthusiasts.