Interestingly, that link takes me to a Gmail error page; however, a Google search found it. There are several versions to choose from, but it's a rather nicely done bit of work, whichever you choose. The fellow has done his homework on getting the lines right, but I think he needs to spend more time coordinating the parts he mentions with the diagram and the model. sorry, but I've been in directorial mode for the last several weeks, and we're getting down to the nit-picking stage.

Thanks for bringing this to my attention. I enjoyed it.