Cogs

A friend of mine makes the most beautiful clocks in the world, completely from wood - as soon as his site is up, you'll re-mortgage your house and buy 20. Whilst he was going through his R&D stage, I knocked up a couple of programs to work out cog ratios and timings - the final result was Cogs3D, an OpenGL program that simulates cog trains and clocks. Windows only I'm afraid, but completely free (and with no warranties whatsoever). A zip file with the executable and some example files is avalable here. The program's pretty self-evident, but if you have any problems, feel free to contact me.