2D Frame Legible Font Creator - Version 5.3.19 With 2D Frame Legible Font Creator you will be able to simulate the non-linear behaviour of a pendulum bob swinging back and forth attached to a spring. It is relatively straightforward to write down the Equations of Motion for this system using the formula for the acceleration of a particle in Cylindrical Polar co-ordinates. If the parameters you choose are too drastic, this model goes spectacularly haywire. .