||pulley, wheel, beam, axle, wall, driver, follower, tension, bushing
||K, 1, 2, 3
||1 Hour Total
||- 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.
||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.
||- 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’.
||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.
- Introduce pulleys
- explain what a pulley is, show some example pictures of pulleys and how they are useful
- Show students the pieces they will be using to build their LEGO pulley (pulley wheel, band).
- Point out the different sized wheels and bands.
- Demonstrate to the class what they will be doing, by constructing an example pulley wheel in front of the class.
- Show the students how your pulley works and ask students to explain how one pulley moves the other pulley.
- 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).
- Ask the students to observe which pulley moves faster when teh small pulley is the driver and when the big pulley is the driver.
- Tell the stuents that they will each build their own pulley wall consisting of 2-pulley wheels (one driver and one follower).
- 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.
- 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).
- Give students hints about how to connect two pulley walls together with an extra beam and pulley band.
- When students are finished have students fill out the ‘Engineer’s Final Report’ and have them label the driver and the follower pulley wheels.
- 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
|Sample Image 2
|Sample Image 3