The piston engine is modeled in the Planar Mechanics library using only revolute and prismatic joints, making it a completely planar model. The flywheel has an initial angular velocity of -2.5 rad/s in order to demonstrate the movement of the engine.

The bottom‐left animation shows the system from a two‐dimensional point of view. The bottom‐right animation shows the same system, but in three dimensions. In other words, we have taken a completely planar model and used Mathematica graphics to illustrate it in a higher dimension. The top plot illustrates how the stored rotational energy changes as the piston moves.