For several years, summer students at Princeton have worked to create mechanical differential analyzers out of K’Nex. Currently, the university has 3 differential analyzers and 1 mechanical integrator (shown above).
While the differential analyzers are almost entirely built from the standard K’Nex parts, several pieces had to be 3d printed in order to make the machines run smoothly. These pieces were all drawn in Creo Parametric and their part files are posted below.
Jack Monaco’s Mechanical Integrator – below – improvement to K’NEX integrator