The stepper motor will rotate a chuck and an external device will take measurements based on the chuck's position. The measurement data will go back to the SBC via a serial cable.

The motor behind it all is a geared stepper motor, and there are a set of printed parts to complete the model. It’s recommended to use PETG, and nylon for the gears, but it would work in PLA ...

You have a project that needs something to move. Should you use a stepper motor or a servo motor? [Matthias] has an opinion, and you can hear his thoughts in the video below.