For a guy like me, it doesn’t get any better than this. Prototyping threaded nuts (to convert radial to linear motion), prototyping software, and printing parts all in one video.
This is demonstrating the creation of nuts to be adhered to the paralleled platforms. As the threaded rod is turned by the stepper motor, the nut moves up and down the rod. The nut is connected to each platform and that platform moves linearly. This is the method used to turn radial into linear motions. Other popular systems use toothed belts, similar to the radiator of a car or a bicycle, but that system requires a constant tension and is prone to wear and to break when exposed in an open environment. In this application, the less moving parts the better.