The definition of a spectrophotometer is an instrument used to measure the intensity of wavelengths in a spectrum of light. An example of spectrophotometer is how an ink manufacturer would figure out how much of one color is present in an ink.
This is a fidgetspinner made from 3mm HDF, a small ballbearing from a 3d printer, and 3 steel balls from a bigger ballbearing. It is made for assembly without glue.
Remember to change the center hole for your bearing size.