An often conceptually difficult topic learned in early engineering courses is known as the angle of twist. The angle of twist is necessary for two reasons: to analyze reactions along a shaft where traditional equilibrium equations do not suffice, and in designing a shaft when twisting is restricted. In this project, the purpose is to design and build a device that will be an aid in classroom demonstrations of the concept and applications of the angle of twist. The prototype of this device is designed to test foam shafts of a certain length and with a constant applied torque. The device will need to support, hold, and twist foam shafts while providing precise measurements of the applied torque and the resulting angle of twist. Two markers will be put in place before twisting. The shaft will be fixed at one end, where one marker will be in place, and twisted at the opposite end where the mobile marker will be used to determine the angle between the two. It must be durable to withstand regular classroom handling and have an appropriate interface for students of varying levels of proficiency in the topic. Its design must also be inexpensive and replicable so that it can be built and used within a low classroom budget. Students will be able to calculate, measure, and observe the applications of polar moment of inertia, angle of twist, and torque using the measurements from the apparatus. From the measurements, the shear modulus of the shaft material will be experimentally determined, allowing for an active learning experience of this key concept.An often conceptually difficult topic learned in early engineering courses is known as the angle of twist. The angle of twist is necessary for two reasons: to analyze reactions along a shaft where traditional equilibrium equations do not suffice, and in designing a shaft when twisting is restricted. In this project, the purpose is to design and build a device that will be an aid in classroom demonstrations of the concept and applications of the angle of twist. The prototype of this device is designed to test foam shafts of a certain length and with a constant applied torque. The device will need to support, hold, and twist foam shafts while providing precise measurements of the applied torque and the resulting angle of twist. Two markers will be put in place before twisting. The shaft will be fixed at one end, where one marker will be in place, and twisted at the opposite end where the mobile marker will be used to determine the angle between the two. It must be durable to withstand regular classroom handling and have an appropriate interface to be used by students of varying levels of proficiency in the topic. Its design must also be inexpensive and replicable so that it can be built and used within a low classroom budget. Students will be able to calculate, measure, and observe the applications of polar moment of inertia, angle of twist, and torque using the measurements from the apparatus. From the measurements, the shear modulus of the shaft material will be experimentally determined, allowing for an active learning experience of this key concept.