Using Geometry to Design Simple Machines

Using Geometry to Design Simple Machines


Daniel D. Frey
Robert Noyce Career Development Professor
Of Mechanical Engineering and Engineering Systems
Massachusetts Institute of Technology
Cambridge, Massachusetts 02139 USA

Lesson Feedback


This video is meant to be a fun, hands-on session that gets students to think hard about how machines work. It teaches them the connection between the geometry that they study and the kinematics that engineers use -- explaining that kinematics is simply geometry in motion. In this lesson, geometry will be used in a way that students are not used to. The prerequisite here is a familiarity with the geometry of triangles and circles. This interactive learning video could be completed in an approximately one-hour class session or it could be presented over two class sessions, allowing more class time for students to engage in hands-on activities. Materials necessary for the hands-on activities include two options: pegboard, nails/screws and a small saw; or colored construction paper, thumbtacks and scissors. Some in-class activities for the breaks between the video segments include: exploring the role of geometry in a slider-crank mechanism; determining at which point to locate a joint or bearing in a mechanism; recognizing useful mechanisms in the students’ communities that employ the same guided motion they have been studying.

Instructor Biography

Dr. Frey’s research concerns robust design of engineering systems. Robust design is a set of engineering practices whose aim is to ensure that engineering systems function despite variations due to manufacture, wear, deterioration, and environmental conditions. Click here to read full bio.

Additional Online Resources

Math Open Reference: Circle through 3 Points
This shows how to construct a circle that passes through three given points.

Open Stax: Simple Machine Elements
A lesson on simple machine elements presented by Connexions of Rice University

Carnegie Mellon University: Introduction to Mechanisms
An Introduction to Mechanisms developed by educators at Carnegie Mellon University