Why use three separate motors, if you can do with one?!
A three-axis stepper motor with concentric output shafts has been developed at RaM. It is intended to be an efficient alternative to three conventional (single-axis) stepper motors and can serve as the main actuation method in suitable applications. Video: https://youtu.be/ObSEM4sE0pg
Your task is to investigate which types of (cool, interesting) applications are suitable for actuation by such a motor, choose one particular application and build a prototype driven by it. For example, a previous student developed a screw-drive in-pipe robot (SDIR) with two different driving types. Another student developed a 3 DOF parallel manipulator which could launch a ping pong ball. A different idea is to investigate a variable-impedance actuator (VIA).
After building your prototype you evaluate it with experiments, analyze the results and draw conclusions. Is the motor suitable for your application, or a piece of junk? Let's find out!