A simple 2 axis 3D scanner was one of the introductory projects for Olin College's Principles of Engineering
course I took during my sophomore year. This resulted in the use of two servos and an IR sensor to create pan/tilt mechanism.
A full write up of the process can be found here.
There existed plans to extend the capabilities to a 3D shell using a rotatary base controlled by a stepper motor but time constraints
of the class meant this did not come to fruition.
Heatmap of a cardboard cutout "Z"
3D point plot of a cardboard cutout "Z"
The Physical Scanner
Schematic of the final scanner