Name of Activity Tug-O-War
Author Kara Miranda
Keywords gear, gear ratios, build, machine, tug-o-war, competition, prototype, Engineering Design Process, torque
Subject NXTs
Grade Level 4, 5, 6, 7, 8, 9+
Time 3 Hours Total
Brief Description Students will use their knowledge about gears and gear ratios to build a machine that will play tug-o-war against another classmate’s.
Lesson Objectives: To apply building techniques and knowledge about gears to an activity challenge.
Materials Needed:
RCX or NXT LEGO kits

Assortment of extra LEGO pieces, especially gears and beams
Engineer’s Planning Sheet

Preparation and Set Up:
Collect necessary materials
Photocopy worksheets
Arrange students into groups of 2
Decide how you will distribute extra pieces
Write design requirements on the board
Necessary Background Review gears, gear ratios, and torque.

Engineering Design Process

Gear ratio

    • Tell students that in this challenge they will be playing tug-o-war by building a machine that can provide enough torque to pull on another machine doing the same thing. String will be tied between the two, and a machine will have to pull the other over a line of tape in order to win.
    • Make sure to review how gears work, gear ratios, and using gears for torque vs. speed. Also explain the engineering design process.
    • Tell students the requirements for their tug-o-war contenders. Examples of requirements are:
    •       Must use gears
    •       Must have a sensor
    • Allow the class to brainstorm different ideas for their machines. Have them plan out and draw their design on the engineering planning sheet.
    • Distribute materials and have students start building. You may have to assist students with tying string to their machine.
    • After the students finish building, pair up machines and tie them to either end of a string, making sure the middle of the string is right above the tape on the ground, and that both machines are equidistant from the tape.
    • Have the students start their machines. Whoever’s machine gets pulled over the line first, loses.
  • After the students finish, review the activity with the class. Have them share their ideas, ask groups to explain what the hardest part of the challenge was, etc.
Extensions: Have students add more gears
Make a classwide tug-o-war competition. Whose is the “strongest”?
Allow those who lose to redesign and compete against each other again
Reference 1
Share →

Leave a Reply

Tufts Student Teacher Outreach Mentorship Program • 200 Boston Ave. • Suite G810 • Medford, MA • 617-627-5888

Switch to our mobile site

Disclaimer | Non-Discrimination | Privacy | Terms for Creating and Maintaining Sites