This is an ellipse trammel machine with a motorized wheel to drive the operating shaft.

I used a couple of bearings for the shuttles and curtain tracks for the tracks. It is crude but fun to watch for a few minutes anyway.

This is often called a bullsh** grinder or "do nothing" machine. But I prefer to call it the Love Machine. Two people revolving around each other are in a relationship powered by love (the motor). But when the power stops, the relationship grinds to a halt. So we need to keep the batteries charged.