The grey heavy gear is the force. Refer to my other posts of an explanation on a model I have been interested in that happens to make a model of the trigonometric function co secant. I have two seperate tensions under the force of mg from the grey gear. The gear rolls in order to find equilibrium, and as it rolls towards its equilibrium state, it causes a difference in the tensions because of their varying angles it makes directly beneath the rolling weight. As it rolls towards equilibrium in an attempt to make both angles equal, it causes an unbalance of forces. Those unbalances gives one of the tensions a higher tension, causing it to tug on the other will with more force. As it tugs on the other wheel, it pushes the machine forward. The spinning weight is locked in place until it starts to gain angular momentum due to the equilibrium unbalance. Every time that weight seeks equilibrium, the redirects the downward force into a series of gears that yank the device forward again. It seems as though it cannot properly reach equilibrium so its forced to roll. Every time it rolls, it pushes tension on the chain which varies in angles due to the difference in diameter of the gears. I'm attempting to send gravity into a forward motion and have done a good bit of mathematics on this general concept without even gears or wheels involved. Please view my other topics if your interested. The attempt is using gravity to make a vehicle that could transport anything along a flat surface. Notice the machine does not move forward if suspended in the air.