Lalbritton's "Ideal Harmonic Transformer" is a 3D printed mechanism for calculating sines and cosines: "
It is a thing to hold, enjoy turning the crank, and look at. If you can't find your calculator, and need to know the sine or cosine of an angle real quick, you can dial in the angle and read off of the Scotch Yokes. It also works in reverse."
Ideal Harmonic Transformer by lalbritton