Learning Goals 3 min
By the end of this lesson you will be able to:
- Build the Ferris Wheel with its Medium Motor in port A.
- Run the wheel at a slow, steady speed so the seats turn smoothly.
- Add a play beep (60) for (0.2) seconds to signal "ride starting" before the wheel moves.
Meet the Model — the Ferris Wheel 6 min
What is a Ferris wheel?
A Ferris wheel is a giant upright wheel with seats — called gondolas — hanging from its rim. It turns slowly to lift riders high for the view, then brings them back down. George Ferris built the first one in 1893 for a great fair in Chicago.
The science behind it
The whole wheel turns around one central axle, called the hub. Thin spokes link the hub to the rim and share the load, like a bicycle wheel. Each seat hangs from a pivot, so gravity keeps it level — you stay upright even at the top. A slow, steady speed makes boarding safe and the ride smooth.
Where you meet it
Ferris wheels turn at theme parks, funfairs and the pasar malam. The biggest are "observation wheels" built for sightseeing. The Singapore Flyer is one. So was the 60-metre Eye on Malaysia, which once turned beside Titiwangsa Lake in Kuala Lumpur.
What we'll build
We'll build a motorised Ferris wheel. One Medium Motor on port A turns the wheel through a gear, with four seats on the rim. Then we program it to give a warning beep and spin slowly and smoothly — just like the real ride.
Warm-Up 4 min
You can set motor speed now. A Ferris wheel needs a slow one, so the seats do not fling about.
Quick-fire puzzle
Kavya runs this on the Ferris Wheel. What do you hear, and then what do you see?
when program starts :: events hat play beep (60) for (0.2) seconds :: sound [A v] set speed to (25) % :: motors [A v] start motor [clockwise v] :: motors
Reveal the answer
First a short beep — the "ride starting" signal. Then the wheel begins turning slowly at 25% speed, and keeps turning (there is no stop block yet). Sound first, motion second.
New Concept — sound as feedback 10 min
The Brick has a speaker. A sound is the robot's way of saying "I am about to do something" — like a lift that dings before the doors close.
Blocks reference
| Block | Category | What it does |
|---|---|---|
play beep (60) for (0.2) seconds :: sound | Sound | Plays a single short beep through the Brick's speaker. |
play sound [Communication / Hello v] until done :: sound | Sound | Plays a built-in sound clip you pick from a list. |
[A v] set speed to (25) % :: motors | Motors | Sets a slow, smooth speed for the wheel. |
Order matters
Blocks run top to bottom, one after another. Put the play beep (60) for (0.2) seconds before the motor block if you want the warning to come first.
Why it matters
Fairground rides, microwaves and reversing lorries all beep before they act. Sound is the simplest feedback a robot can give. It is also a handy way to check your program reached a certain line.
Build & Program — the Ferris Wheel 17 min
Part A — Build
Build the Ferris Wheel. A Medium Motor turns the wheel through a gear; four seats hang from the rim.
Components & ports: EV3 Brick · Medium Motor → port A.
- Build the wheel rim and clip the four seats so they swing freely.
- Mount the wheel on a central axle held by the tower frame.
- Attach the Medium Motor to drive the axle through a gear; plug it into port A.
- Spin the wheel by hand to check the seats stay level.
Part B — Program
Beep to warn riders, then turn the wheel slowly for a set ride length.
- Drag in the hat that starts the program:
when program starts :: events hat
- Add the ride-starting beep:
play beep (60) for (0.2) seconds :: sound
- Set a slow, smooth speed:
[A v] set speed to (25) % :: motors
- Turn the wheel for one full ride:
[A v] run [clockwise v] for (5) [rotations v] :: motors
when program starts :: events hat play beep (60) for (0.2) seconds :: sound [A v] set speed to (25) % :: motors [A v] run [clockwise v] for (5) [rotations v] :: motors
Expected behaviour: the Brick beeps, the wheel turns slowly and smoothly for five rotations, and stops itself — one full ride.
What changed: for the first time the robot gives you feedback (the beep) before it moves.
Try It Yourself — three small builds 11 min
Goal: A longer ride at the same gentle speed — 12 rotations.
when program starts :: events hat play beep (60) for (0.2) seconds :: sound [A v] set speed to (25) % :: motors [A v] run [clockwise v] for (12) [rotations v] :: motors
Goal: Beep at the start and the end, so riders know the ride is over.
when program starts :: events hat play beep (60) for (0.2) seconds :: sound [A v] set speed to (25) % :: motors [A v] run [clockwise v] for (8) [rotations v] :: motors play beep (60) for (0.2) seconds :: sound
Goal: Nurul wants a louder "all aboard" clip instead of a plain beep. Use a play sound [Communication / Hello v] until done block at the start, then run the ride.
when program starts :: events hat play sound [Communication / Hello v] until done :: sound [A v] set speed to (25) % :: motors [A v] run [clockwise v] for (8) [rotations v] :: motors
Mini-Challenge — the two-stop ride 6 min
Combine today's beep with last lesson's speed control. Make the wheel run, pause to let riders off, then run again — with a beep before each move.
It works if:
- A beep sounds before each of the two rides.
- The wheel pauses for 2 seconds in the middle.
Recap 2 min
You added sound feedback. play beep (60) for (0.2) seconds plays a short signal through the Brick's speaker, and blocks run top to bottom — so a beep before the motor warns riders first. A slow speed keeps the ride smooth.
- play beep (block)
- Plays a beep of a chosen pitch for a set number of seconds — the simplest sound feedback.
- play sound (block)
- Plays a built-in sound clip chosen from a list.
- Feedback
- A signal — sound, light or screen — that tells you what the robot is doing.
Homework 1 min
Ride designer. Pick a ride speed and length you think feels realistic. Add a beep at the start and end.
Bring back next class: a screenshot of your program and a one-line note on why you chose that speed.
Heads up for next class: EV3-L1-05 builds the Apache Helicopter and shows pictures and text on the Brick screen.