Rewind your Mind

As your school or library discards old videocassettes, consider using them in a simple engineering lesson before recycling the materials in them.


  • Old video cassettes
  • Set of screwdrivers

Assemble your students into teams and examine the video cassettes. They can predict how many individual parts are involved in its operation. Similarly, they may estimate the length of the tape. Once the prediction and estimate is complete, allow students to disassemble the cassettes, recording and sketching the components as they work through the process. As a thinking exercise, ask them to propose alternative materials that could have been used in place of the original. Perhaps they will propose greener options. As they work, see how they are able to process, manipulate, disassemble and keep track of the tiny and delicate structures.

I provide a bin for them to store the parts if they want to return to the project at a later time. Also, a film canister provides a convenient place to store the screws, spindles and smaller components.

Ask the teams to re-assemble the videocassettes, invite comments on the efficiency of the design and materials science involved with each component. If possible, ask each team to reveal the approximate date of manufacture for their cassette and the number of parts contained in it. Plot the date vs number of parts for each team’s cassette and try to identify a pattern in this data. If you have several classes completing this activity, aggregate the data for all of them into one graph.