Robert Burke, the author of the ‘Precision Modelling PDF Guide‘, has published an interesting article on the modeling and rigging of a mechanical guide.
Robert writes:
I have been working on this model for some time now and rather than repeating the usual step by step tutorials I have decided instead to write a brief article. The article will detail the process and a few of the techniques used to get to get from the first idea to construct a complex mechanical model that could be animated, to the finished excavator.
Link
