Torsion Testing Rig

I designed this testing rig as a TA for a graduate-level mechanical design course at Carnegie Mellon University. The rig applies 200 Nm of pure torsion (no bending, axial, or shear forces) to test the strength of students' parts.

I designed the testing rig to minimize cost and fabrication time, while being able to handle loads over 200 Nm. As such, most of the parts of my rig consist of 80/20 and other readily available components. My design implements long lever arms to generate a high moment without resorting to a dangerous amount of weight and the central spine incorporates a hollow-tube design which is simple to construct yet still withstands large torques. The 200 Nm load was generated by hanging a 40 lb weight off the end of the steel handle, which itself accounts for part of the load. Bronze bushings reduce friction and ensure the load is transmitted to the students' parts.