Wheel and Axle Lesson

ACTIVITY HEADER

 

 

 

Name of Activity Wheel and Axle Lesson
Author STOMP
Keywords Simple Machines, Wheel and Axle, NXT
Subject NXTs, Simple Machines
Grade Level 5, 6, 7, 8
Time 2 Hours Total
Brief Description Students work in groups to build a vehicle using NXT kits that includes a wheel and axle and has to be able to hold a ball. To discourage everyone from using a basic car design, their designs cannot have exactly four wheels. Once their design is complete (including motors and the NXT brick), each group learns how to use on brick programming to make their vehicle move the ball across their workspace.
Lesson Objectives: Improved understanding of the wheel and axle as a simple machine. Students gain skill building with NXT kits and using on brick programming.
Materials Needed: -NXT kits (1 per group)
-extra Legos
Preparation and Set Up: Consider bringing extra Legos for groups to build with, prepare to talk about the project in terms of the Engineering Design Process and simple machines.
Necessary Background None
Procedure
  1. Introduce the project by talking about the importance of the wheel and axle as a simple machine.
  2. Tell them the objective: to make a vehicle that can’t have exactly four wheels, includes the NXT brick and motors, and is capable of carrying the NXT ball across their workspace.
  3. Explain the project in terms of the Engineering Design Process, discuss which steps would be best to focus on for this project.
    • We drew the entire Engineering Design Process on the board and went over each step, asking them how they though the steps fit into this activity. At the end of the discussion we decided that the most important steps for this activity would probably be developing/ sketching solutions, prototyping, and communicating with other group members.
  4. Separate students into groups of 3-5.
    •  Most teachers already have some method of grouping students, or know which students shouldn’t be in a group together.
  5.  Give them the rest of the first hour to sketch a design and then build it.
    • Make sure each group includes motors and the NXT brick into their design.
  6.  If the lesson is taking place over two, one-hour blocks leave 5-10 minutes at the end of the first block for cleanup.
  7. Once a group has their vehicle fully assembled, show them how to make it move using on brick programming.
    • Make sure each member of the group gets a chance to try programming, and show them how to do things like change direction, turn, and loop through a set of instructions.
  8. If any of the groups finish early, show them how to add sensors and change the on brick program to respond to sensor input.
  9. Leave 15 minutes for each group to demonstrate their finished vehicle and clean up.
Umbrella Unit/Curriculum (if applicable) Simple Machines

Relay Race

ACTIVITY HEADER

 

 

 

Name of Activity Relay Race
Author STOMP
Keywords vehicles, steep ramp, relay, team, course, cars, gears, weight, weight distribution, friction, power, accuracy, wheel, axle, speed
Subject NXTs
Grade Level 4, 5, 6, 7, 8, 9+
Time 2 Hours Total
Brief Description Students will build two types of vehicles, one that is good for going fast on a flat surface and one that is good for climbing a steep ramp. Students will work together to create a relay team of 2 cars that must complete a course with a flat area and a steep ramp.
Lesson Objectives: To learn about gearing and how it can help with climbing ramps.
To learn complex programming that includes Bluetooth for communication between NXTs.
Materials Needed: Poster board, cardboard, wood or foam core for a ramp sloped about approx. 30 degrees from the horizontal.
NXTs or RCXs
Gears
Assorted building materials.
Computer running ROBOLAB or MINDSTORMS
Preparation and Set Up: Setup the relay course.
Set up a flat track that is five feet long with a start and finish and set up the ramp.
Collect necessary materials.
Arrange students into groups of 4.
Distribute the necessary materials.
Necessary Background One of the important things about robots is their ability to communicate to each other. Robots are often limited in their capabilities because it is too difficult to construct multi-tasking robots. For this reason, many different specialized robots are constructed, and then these robots are programmed to communicate to each other. For example, a certain Mars rover may specialize in searching for rock, while another may specialize in drilling rock. These two rovers can work together by sending signals to each other, in the same way we communicate, yet simpler. The following activity incorporates specialized robots that can communicate to each other to complete different sections of a single task: a relay race with different terrain.

CONCEPTS:
Building

Mechanical advantage of gears
- Small gear on motor, larger gear on wheel and axle for more torque to drive up the ramp
- Large gear on motor, small gear on wheel and axle for more speed to drive across the floor

Weight distribution of vehicle
- More weight on the front of the ramp vehicle
- Less weight for the entire floor vehicle

Friction
- Wide wheels for more contact surface area on the ramp vehicle
- Narrow wheels for less contact surface area on the floor vehicle
- Spacing between wheels and sides of vehicle so that the wheels rotate without rubbing

Power
- Large diameter wheels in the front of the ramp vehicle
- Ramp vehicle should be short in length

Accuracy
- Long floor vehicles with four wheels to ensure that the vehicle travels as straight as possible towards the stationary ramp vehicle

Procedure
  1. Introduce the activity and tell students that two people in their group will build and program a car to travel as fast as possible on a flat surface, and the other two people will be building a programming a car to drive up a ramp.
  2. Allow students to build their cars. Remind students that gears might help them build a car that can climb a ramp.
  3. Have students program their vehicles.
    1. The first vehicle must travel 5 feet to the base of a ramp and then stop. The students should use time to stop their robot, or use a light sensor if the course is marked with tape.
    2. When the first vehicle stops, it must send a message to the second vehicle (a number). This will trigger the second vehicle to start climbing the ramp.
    3. The second vehicle should start climbing the ramp when it receives the message from the first vehicle.
    4. Communication between RCXs/NXTs may be tricky.
      1. Use the ‘send mail’ and ‘wait for mail’ icons on the floor and ramp vehicle, respectively.
      2. Each group should send a different number so as to avoid confusion between RCXs and NXTs.
      3. Zero the receiving mailbox at the beginning of the program.
      4. Press run on both robots before starting the relay.
  4. Allow students to test their cars and rebuild/reprogram accordingly.
  5. At the end of class gather the students together. Have each team run their cars and time how long the relay takes from start to finish.
  6. Talk about what designs and programs worked the best and how you could improve upon each teams work.
Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/Team-up-for-a-Relay.doc

Bicycle Unit: Engineering the Wheel

ACTIVITY HEADER

 

 

 

 

Name of Activity Bicycle Unit: Engineering the Wheel
Author STOMP
Keywords bikes, force, friction, rolling, ramp, travel, wheel, tire, LEGO
Subject LEGO Building
Grade Level 4, 5, 6
Time 1 Hour Total
Brief Description Using bikes as an example, students will examine the force of friction. They will apply their knowledge to build an object that rolls down a ramp and travels as far as possible.
Lesson Objectives: - To experiment with wheel sizes, shapes, and materials.
- To learn about the affect of friction on bike tire design.
- To practice teamwork and competition.
Materials Needed: - Ramp (made of wood, cardboard, foamcore etc.) that is approximately 25 cm high at the top.
- Tape lines to mark where to start measuring distance.
- Ruler.
- ‘Ramp Roller Challenge’ and ‘Tire Chart’ Worksheets.
- Homemade LEGO kits (consisting of different types of wheels, axles, bushings, beams, bricks and weighted bricks).
OR:
- Other materials that cars could be constructed out of:
– Wood, cardboard, straws, old containers, art supplies, blocks, etc.
Preparation and Set Up: - Create kits to make cars with.
- Make a ramp that is about 25 cm high and mark starting point on ramp and start point for measuring distance at the bottom of the ramp.
- Photocopy a ‘Tire Chart’ worksheet for each student.
- Photocopy a ‘Ramp Roller Challenge’ Worksheet for each student.

- Arrange students in pairs.
- Distribute materials.
Necessary Background Wheels must respond to a lot of forces. Riders weight, Bumps and dips, Weight of the frame, Wheel itself.
Friction is a force that affects the wheels of a bike because tires are the part of the bike in contact with the road. Friction is the force that appears when two things rub together (rub your hands – makes heat). The smoother two objects sliding against each other are, the less friction there is. Microscopic ridges are what interact with each other when any two objects meet. If a wheel had no friction it would not be able to move a bike; it would just spin in one place. However, too much friction causes a rolling wheel to slow down, and makes it harder to pedal.

Vocabulary:
Friction
Force

Procedure Part 1:

  1. Show students two different bike tires; one from a mountain bike and the other from a road bike (pictures are fine, the real thing is better).
  2. Have each student fill out the ‘Tire Chart’ worksheet attached to this document to examine the properties of each wheel and the reason that property is there.
    1. E.g., MOUNTAIN BIKE WHEEL - Property: wide tires, Reason for Property: More surface area on the ground for better stability
  3. Discuss, as a class, the different forces on tires and the design features that account for these forces.

Part 2:

  1. Have students build an object that will travel the farthest once it rolls down a ramp.
  2. Remind the students that you used the word “object” because they do not have to design anything that resembles a car.
  3. Once students have built their original design, let the students test their design on the ramp.
    1. Students should record their results on the ‘Ramp Roller’ worksheet: the distance traveled from the bottom of the ramp, and the design changes that they make.
  4. Have students redesign or make changes to their original design and retest.
  5. Students get a total of three trials.
  6. When everyone has finished bring the class together for  class discussion.
    1. Talk about different factors that affected the distance the cars traveled.
    2. Talk about how weight might have affected their cars.
      1. Tell students that, for some of their designs, adding weight did not help because it added friction to the place that the axle went through the beam. The more mass on the car the more friction there would be between the wheel’s axle and the hole that supported the rest of the car.
    3. Compare different designs.
      1. Which design was the best?
      2. How could other designs be improved?
    4. Review how friction affected designs, and point out all the different places that friction had an effect on a vehicles performance for each model.
Reference 1 http://sites.tufts.edu/stompactivitydatabase/files/formidable/bicycle1.pdf
Reference 2 http://sites.tufts.edu/stompactivitydatabase/files/formidable/bicycle2.pdf
Reference 3 http://sites.tufts.edu/stompactivitydatabase/files/formidable/bicycle3.pdf

Pulley Wall

ACTIVITY HEADER

 

 

 

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.

Procedure
  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

Switch to our mobile site