This flash animation is a modified version of Ferguson's Parodox. It is modified for 2D visulization of a 3D mechanism.
Here is a simplified version of the Ferguson's paradox: Three wheels on the same axis mesh with one thick wheel. Turn the thick wheel (green). One of the thin wheels goes forward (purple), one backwards (yellow), and one goes no way at all (blue).
To better visualize the paradox in 2D, in this animation the thick wheel (green) and the arm split to three peaces and distributed 120 degrees apart. To visualize actual device collapse 3 arms and 3 green wheels to one.
When you observe the animation, you will notice that only the green wheels are rotating and the other outer wheels not rotating at all. However if you click Dials On/Off button you will see dials attached to outer wheel. You will also notice that dial of blue wheel is not rotating, while yellow dial rotating counterclockwise and purple clockwise. This is accomplished by hawing outer blue disk have 32 teeth as the sun wheel, purple has 31 and the yellow has 33 teeth's. The green wheel has 24 teeth's but this number is not important for the operation of this device.
Gears are drawn by using Gear Draw program.