As I stated in a previous post, I now use Google SketchUp for my 3D CAD drawings and renderings. I prefer this medium versus some of the others because:
1. Its free.
2. Does not require much in computer resources (doesnt bog down my comp)
3. Large community of help files and movies
4. Can be converted to other file formats
5. Has excellent add-ons that are again free.
One add-on in particular, Sketchy Physics, is one that I particularly enjoy. This add-on enables animations on the Google SketchUp renderings with a wide range of versatility and interactive control without having to consult a software and graphics engineer. Not only can the movement of levers, wheels, and gears be animated into complex machines but also magnets and floating objects. These objects can then be added to an interactive environment to test multiple object collision and gravity. In addition, interactive controls can be added to change motor speed and direction or adapted to enable steering. Or objects can be dragged and dropped to see possible scenarios. If you have a decent movie screen capture software, a screen capture of the animation can be utilized to showcase the 3D rendering in action. Sketchy Physic Examples
Now dont get me wrong, there are plenty of examples in gif (graphic interchange format) and Flash that are excellent for illustration tools for instructional purposes. But the majority of the examples only show and do not have any interaction. Sketchy Physics bridges this gap by providing an easy method of animation control for an average user with basic drawing skills without having to learn an entire programming language or graphic programming interface like Flash or Java (which is usually in the realm of software graphic engineers).
Examples of Mechanical Animations using Flash or gif