Wall Follower





Name of Activity Wall Follower
Author Jay Clark
Keywords NXTs, car, wall, distance, loops, conditional loops, sensor, threshold
Subject NXTs
Grade Level 4, 5, 6, 7, 8, 9+
Time 1 Hour Total
Brief Description Students will program their NXT cars to follow the outer edge of the classroom by driving along the wall at a set distance away.
Lesson Objectives: Programming using loops and conditional loops
Determining and Implementing sensor thresholds
Materials Needed: Prebuilt NXT car with a sound sensor
Clear wall space
Computers with NXT Mindstorms software
Preparation and Set Up: Find a section of the room that has the most dynamic wall. -Maybe the wall juts out for a closet and back in again afterwards-

Clear this space for cars to run next to.

For any inside turns (turning to the right if the wall is on your left), place a strip of black tape a foot or so away from the wall for the extensions.

Necessary Background A wall follower activity is very similar to the line follower programmatically. Start close to the wall. Turn away from the wall until the distance sensor reads that you are too far, then drive back towards the wall until the distance sensor reads that you are too close. Loop.

There is a challenge in trying to get the car to make an outside turn. This involves playing with the distance away from the wall you set your car to follow, and how dramatically you have the car steer.

Inside turns cannot be made using the loop. Some other sensor must tell the car that an inside turn is approaching, and then the car must react by turning. Students may use a touch sensor, a light sensor, a sound sensor, or even another distance sensor (if they have one)

Vocabulary: Threshold – The sensor value that when breached, will trigger a wait for block or a conditional loop. (Some students have had a better time understanding it as a “benchmark”)

Procedure Introduction – 10 minutes Introduce/ Review loops with the students and why they are useful in programs.

  • Loops allow us to repeat a set of commands that would otherwise be tedious to program over and over.

Introduce the activity, and ask the students if they have an idea of what the program should look like. Activity – 40 minutes Allow students to make the mistake of not including any turns in their program. They will understand their mistake when trying to make the first outside turn. Clean up/ Wrap up – 10 minutes

  • What was easiest? What was hardest?
  •  What would you have done differently?
  •  What were some good ideas you saw that other groups came up with?
Extensions: In order to make inside turns, students will have to use a conditional loop and another sensor to warn them of the upcoming turn.
Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/c1.jpg
Reference 2 http://sites.tufts.edu/stompactivitydatabase/files/formidable/d.png

Things That Go Bump





Name of Activity Things That Go Bump
Author STOMP
Keywords design, construct, NXT, car, bump, wall, damage, touch sensors
Subject NXTs
Grade Level 4, 5, 6, 7, 8, 9+
Time 1 Hour Total
Brief Description In this activity, students will design and construct an NXT car that will stop when it
bumps into a wall to prevent damage to the car.
Lesson Objectives: - To learn to program with touch sensors.
- To create a safety device for an NXT car.
Materials Needed: - NXT Car.
- Assortment of LEGO pieces.
- Computer running NXT software.
Preparation and Set Up:
Set up computers running NXT software.

Arrange students in groups of two.
Distribute necessary material to students.

Necessary Background Vocabulary:
  1. Have students draw out the design for the bumper that they will attach to the front of their car
  2. Have students build an NXT car.
  3. Have students attach a bumper to their car attached to the touch sensor so that the car can respond when it drives into a wall.
  4. Wire the motors to the outputs and the sensors to the inputs of the NXT.
  5. Program the NXT vehicle:
    1. If using NXT MINDSTORMS software, program the car to stop when it hits a wall.
    2. Once students have program their car to stop when the touch sensor is pressed, have students program their car to back up and turn after the car hits a wall, before driving forward again. This program requires a loop.
Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/69_image_3.jpg
Reference 2 http://sites.tufts.edu/stompactivitydatabase/files/formidable/69_image_3.png
Reference 3 http://sites.tufts.edu/stompactivitydatabase/files/formidable/Bumper_car.doc

Build a Sturdy Wall





Name of Activity Build a Sturdy Wall
Author STOMP
Keywords sturdy, wall, tests, overlapping, drop test, flick test, plate, beam, brick, Simple Machines
Subject Simple Machines
Grade Level K, 1, 2, 3
Time 1 Hour Total
Brief Description Students will build a sturdy wall that can withstand two different tests.
Lesson Objectives: - To familiarize students with LEGO building strategies.
- To familiarize students with LEGO and engineering vocabulary.
- To introduce the Engineering Design Process to the students.
Materials Needed: - LEGO Simple Machines kits or homemade LEGO building kits.
- Engineer’s ‘Final Report’ Worksheet.
Preparation and Set Up: - Arrange students in pairs.
- Distribute LEGO Simple Machines Kits.
Necessary Background Vocabulary:
Drop Test
Flick Test


  • Introduce the LEGO pieces students will be using in this lesson.
  • Discuss how to describe LEGO pieces (e.g. a 2 x 4 brick is a brick that is 2 studs across and 4 studs long)
  • Write the pieces that were introduced and tell the students that they are only allow to use and take out those three piece types.
  • Explain the challenge and using steps of the Engineering Design Process:
  1. Create: The task for the day is to build a sturdy wall.
    1. Give building tips and talk about sturdy building. For example, overlapping bricks and beas are stronger than non-overlapping bricks and beams, three plates is the same height as one brick. Talk about overlapping bricks at corners of buildings
  2. Test: Each wall must pass two tests:
    1. Flick Tests - Wall cannot fall apart or fall over when gently pushed.
    2. Drop Test - Wall cannot fall apart when dropped from the knee.
  3. Redesign: Have students think about why their design might have broke and what they can do differently to change it.
  4. Share: 
    1. Have students fill out their ‘Engineer’s Final Report’ Worksheet (some students may need help).
    2. If there is time have students come together to share their wall designs and discuss what made their designs sturdy. Compare the students’ walls to the walls in the classroom/other buildings.
Extensions or Modifications: - Have students build a 2-sided wall (the two walls should be connected with overlapping beams/bricks/plates).
- Have students build a 4-sided sturdy house.
Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/wall1.pdf
Reference 2 http://sites.tufts.edu/stompactivitydatabase/files/formidable/wall2.pdf

Pulley Wall





Name ofActivity Pulley Wall
Author STOMP
Keywords pulley, wheel, beam, axle, wall, driver, follower, tension, bushing
Subject Simple Machines
Grade Level K, 1, 2, 3
Time 1 Hour Total
Lesson Objectives: - Introduce students to pulleys and how pulleys work.
- Teach students new LEGO pieces (pulley wheel, pulley band).
- Show students how pulleys can be useful in engineering and elsewhere.
Brief Description Each student will build a 2-pulley wheel pulley using a beam, 2 pulley wheels, 2 axles, 2 bushings, and a pulley band. Each team of students will connect their pulley walls together so that one driver turns the other three pulley wheels.
Materials Needed: - LEGO Simple Machine Kit.
- ‘Engineer’s Final Report’ Worksheet.
Preparation and Set Up:
- Arrange students in pairs.

- Distribute LEGO Simple Machine Kits.
- Make copies of ‘Engineer’s Final Report’.

Necessary Background Pulleys consist of one or more wheels with a rope or band that wraps around the grove
on the circumference of the wheel. Pulleys are used in many different engineered designs.
A simple example is a well that has one pulley wheel and a rope, used to lift a bucket.
Other examples include, belt systems in cars, roping on sail boats, and in cranes.

Driver – the pulley wheel that is moved by a motor or person.
Follower – the pulley wheel that moves when the driver moves, a pulley system
can have more than one follower.
Tension – The tightness of the pulley band or rope.

  1. Introduce pulleys
    1. explain what a pulley is, show some example pictures of pulleys and how they are useful
    2. Show students the pieces they will be using to build their LEGO pulley (pulley wheel, band).
      1. Point out the different sized wheels and bands.
    3. Demonstrate to the class what they will be doing, by constructing an example pulley wheel in front of the class.
    4. Show the students how your pulley works and ask students to explain how one pulley moves the other pulley.
    5. Introduce the vocabulary and talk about the driver and follower (the one you turn is the driver and the one that turns as a result is the follower. The driver and follower can switch).
    6. Ask the students to observe which pulley moves faster when teh small pulley is the driver and when the big pulley is the driver.
    7. Tell the stuents that they will each build their own pulley wall consisting of 2-pulley wheels (one driver and one follower).
      1. If students have trouble show them how the tension of their pulley band may be affecting its performance, either too tight or too loose. This can be fixed by using different sized bands or moving the pulley wheels up and down the beam.
    8. Explain that once each student has constructed their own wall, they will attach their wall to their partner’s wall to make a long pulley with four pulley wheels (one driver and three followers).
    9. Give students hints about how to connect two pulley walls together with an extra beam and pulley band.
    10. When students are finished have students fill out the ‘Engineer’s Final Report’ and have them label the driver and the follower pulley wheels.
    11. Allow each group to demonstrate their pulley wall and how they work.
Extensions or Modifications: - Have students add a pulley wheel to make even longer pulley walls (teacher may need to supply extra wheels and bands).
- Let two groups work in a team of four to attach their pulley walls to make an 8 wheel wall.
Sample Image 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/11_image_1.png
Sample Image 2 http://sites.tufts.edu/stompactivitydatabase/files/formidable/11_image_2.png
Sample Image 3 http://sites.tufts.edu/stompactivitydatabase/files/formidable/pdf.png

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