Here’s a neat way to show kids how the parts work and move in a very simple automaton (e.g. moving machines like cuckoo clocks), with no fancy equipment required!
To start, place a plastic cup over cardboard and trace four times to make four circles. Use hot glue to make two stacks of 2 circles, then poke a sewer up through the center of each pair. The cardboard circles are the “cams” and the skewer is the axle.
Next, poke a hole in the top of a shoebox, as well as one in each side. Widen the holes so they are big enough for cut pieces of a plastic straw to fit through; use a little hot glue to secure the straw in the holes.
Slide the skewers through the straws; they should be able to spin freely.
Arrange the cams such that the lower one holds up the top one. When you spin the horizontal bottom skewer, the top cam spins! I only got a few second of video, but it was neat for the kids to see this in motion!
For a little fun, we added a “monster” on top. A little green marker, wiggle eyes, and a jagged mouth turned a simple paper cup into a scary creature.