I'm sure most of you are familiar with the CAD program called "Interactive Physics". http://www.interactivephysics.com/ . I started using this program a couple months ago. I have been, for fun, playing with some theories that I have thought up over the past 15 or so years. I started out by creating some of the typical Perpetual Motion Machines of yesteryear, just to watch them fail for myself, of course, they did fail, quickly. I then started modifying them and adding some of my theories, trying out some of my ideas, and somehow I was able to create a machine that actually works, on the computer anyway. It starts, speeds up and runs contiuously under its own weight. It is very slow, so I doubt it would have any useful application in real life. I thought that maybe friction was not being taken into account, so I added resistance to it, and it still works. Has a working computer model ever been made? If so has that model been built only to fail in real life? What am I overlooking here? Please help me make this machine fail so I can stop wasting my time, or I might be forced to actually build a real life model, and I just don't have the time!