Musicboxes

http://whitneymusicbox.org/

rotating cylinders a la astrolabes

spherical astrolabe

calculate n-times rotation / min. of various diameters

public class SpinningBox : MonoBehaviour {
 
    public float yawDegreesPerSecond = 10.0f;
 
    // Update is called once per frame
    void Update () {
        Vector3 localEulers = transform.localEulerAngles;
        localEulers.y += yawDegreesPerSecond * Time.deltaTime;
        transform.localEulerAngles = localEulers;
    }