Lesson 2 of 6 · 8 min · +90 XP
How robots move
- Tell DC motors, servos, and steppers apart
- Explain when each motor type is the right pick
Every millimetre of robot movement is something an engineer had to design. Movement isn't free — it costs power, time, and precision.
The component that turns electricity into motion is called an actuator. The most common kind is the motor.
Three motors that run the world
DC motor — spins fast and cheaply. ₹50–₹500 on Amazon.in. Used in toys, drones, vacuum cleaners.
Servo motor — knows its exact angle. Tell it "go to 90°" and it goes. ₹80–₹400 for hobby servos. Used in robotic arms, RC cars, camera gimbals.
Stepper motor — moves in tiny precise steps. Used in 3D printers, CNC machines, anything that needs millimetre-accurate motion.
A simple rule
- Need speed and cheap? DC motor.
- Need precise position? Servo or stepper.
- Need force at slow speed? Add a gearbox.
This is the first design decision in any robot project. Get it wrong and nothing else works.
You're building a robot arm that needs to hold its position at 60° accurately. Which motor type fits best?