This file prints a set of parts for making a simple automaton, or cranked machine. It is scaled for use with 1/4 inch (6.35 mm) dowel rods. It includes a crank with a knob, several cams, crankshaft arms, a pushrod connector, and some tight-fitting washers.

I created the parts with Tinkercad. I printed it on my Original Prusa i3 MK2.5 in PETG at .2mm layer heights, and it works well. I have not tried scaling it up for larger dowels, but I suspect it will work fine.

I don't know if my video will upload, but the parts can be seen in action out Youtube: https://youtu.be/e-Ed6KFVhrs