I'd like to share this link to an article that I submitted to Am. J. Phys. this week.
http://arxiv.org/abs/1408.3047
In the article I discuss some simulations run on EJS. They are based on a very simple system that is a "first cousin" of Foucault's pendulum.
I believe that this is a direct and interesting way to understand the rate of precession :)
Abstract: "This article aims to answer the question, "What is the simplest system that embodies the essence of Foucault's pendulum?" We study a very elementary idealized system that exhibits a precession behavior analogous to the classic pendulum. The system consists of a particle without inertial mass, constrained to an inclined plane that rotates about a vertical axis. Insights gained from this analysis are used to understand the rate of precession in a straightforward way".
