Edward Somerset, Sixth Earl and Second Marquis of Worcester (1601-1667) published in 1663 the book A Century of Inventions.  Somerset was a prominent public figure, interested in science, mechanics and mathematics, and made useful suggestions and improvements for them, especially for the use of steam as a motive power.  He has some claim to being the inventor of the steam engine.

In the 56th article of his book, he describes a perpetual motion wheel.  The original edition of A Century of Inventions does not have an image of the described machine.  The image frequently published as Somerset's overbalanced wheel was published by Desaguliers and dates from 1720.  The sketch does not reveal much, for it does not show more than a large enclosed wheel with a relatively small axle connected to a rope for lifting weights and performing other mechanical work. Somerset's description reveals these facts:

"To provide and make that all the weights of the descending side of a wheel, shall be perpetually farther from the center, than those of the mounting side, and yet equal in number and heft to one side as the other.  A most incredible thing, if not seen; but tried before the late King (of blessed memory) in the Tower by my directions, two extraordinary ambassadors accompanying his Majesty, and the Duke of Richmond, and Duke of Hamilton, with most of the Court attending him.  The wheel was fourteen feet over, and had forty weights of fifty pounds apiece.  Sir William Balfore, then Lieutenant of the Tower, can justify it, with several others.  They all saw, that no sooner these great weights passed the diameter line of the lower side, but they hung a foot farther from the center; nor no sooner passed the diameter line of the upper side, but they hung a foot nearer. Be pleased to judge of the consequence."

Larry McCart created this design for a gravity motor on December 13, 2005.  With a chain of 36 gravity-controlled panels (each panel weighing 100 pounds) there would be about 1800 pounds on the right side and about 1200 pounds on the left side, resulting in a net pull of about 600 pounds moving at a speed of about 10 miles per hour, enough force to push a full-size car to a speed of 60 miles per hour assuming a 6:1 gear ratio.  Gravity devices would be used to open and close the panels, gravity devices that would be independent of the other part of the system.  Instead of two wheels, there would be one gear on the compressed side, and the panels would roll on ball bearings on metal tracks.

If the prototype gravity motor for the design in picture 1 did work, how could a gravity motor be started or stopped?  Pictures 2 and 3 show an idea by Larry McCart as to how this can be done.  A prototype gravity motor for the design in picture 3 would have roller units all the way around and connected.  Picture 2 shows how three of the roller units would look.  A rod would connect each roller unit to a movable center shaft.  The center shaft would be in the center for neutral, to the left for forward, and to the right for reverse.

Picture 1 - clockwise rotation

Picture 2 - counter clockwise rotation

Picture 3 shows a design by Larry McCart for a roller unit that would have an outside part and an inside part so that the force required to open or close a roller unit with a rod can be minimized.  For example, at the top of the circle the outside part of the roller unit would be pushing the track roller bearings out and the inside part of the roller unit would be pushing the track roller bearings in.  If the two opposing forces are balanced correctly, the rod force required to open or close a roller bearing unit can be minimized.

Picture 3 - clockwise rotation

Picture 4 shows a design by Larry McCart for a roller unit that would have a weight attached to the opposite leg of a roller unit that would assist the rod (attached to the other leg) in opening and closing the roller unit.  Regarding the roller unit on the right side in picture 4, the weight would push the top leg out, and the rod would pull the bottom leg out.  Regarding the roller unit on the left side in picture 4, the weight would push the bottom leg in, and the rod would push the top leg in.  The design in picture 4 probably would provide more power when the center shaft was in the forward position because of additional pull caused by the weights and because the rods probably would push and pull with less force, but probably would not be practical for putting the motor in reverse if the the center shaft were moved to the reverse position.

Picture 4 - counter clockwise rotation

Picture 5 shows a design by Larry McCart that is better for holding things in place as the panels and the inner circle turn.  The panels would be connected to the inner circle at just one point.  The outer circle would be stationary except for moving to the right side for forward, to the center for neutral, and to the left side for reverse.

Picture 5 - clockwise rotation

Picture 6 shows a design by Larry McCart where the inside circle moves to one side or the other for forward or reverse.

Picture 6

Picture 7

Picture 8 shows a design by Larry McCart where the inside track moves left for clockwise rotation, and where weights causing leverage force (force not taken from panel rotation and force occurring because of gravity pull) have been added to reduce the amount of force taken from panel rotation to cause panels to change from narrow to wide and from wide to narrow.

Picture 8 - clockwise rotation

Picture 9 shows a design by Larry McCart where the inside track is moved to the left for clockwise rotation.  As can be seen in picture 9, the inside track does not need to move very far to the left to cause movement to occur.  In picture 9 a small movement of the inside track to the left results in a 6:11 force ratio.  If 600 pounds were on the left side, with a 6:11 force ratio a force of 1100 pounds would be on the right side, resulting in 500 pounds of dynamic force being available for generating electricity or powering a vehicle.  

Picture 9 - clockwise rotation

Designed by Donald Simanek and Hans-Peter Gramatke in November 2005, this GIF image shows the principle of overbalance.  In the GIF image a continuous coiled spring under some tension is supported by two gears connected by a timing-belt, the whole thing arranged so that in the GIF image there is more weight on the right side.  Read more about it

Drawing a design for a gravity motor on paper is one thing; actually getting a prototype made is something else.  In the past it is possible that an inventor created a design for a gravity motor that would have paved the way for mass production of powerful and pollution-free gravity motors -- if a prototype gravity motor had been made to prove that the inventor's design was practical.  In the USA many individuals can afford to buy their own equipment for making a prototype.

A big lathe probably is the most important item needed.  Larry McCart bought a vertical lathe on Ebay for about $2,600.  The lathe weighs 33,000 pounds, and has a 48 1/2 inch chuck and a 54 inch swing.  The machine was said to be in good working condition when it was replaced by a CNC lathe about two years ago.  The machine was located near Sacramento, California, and the shipping cost was about $300.  A 44,000-pound-capacity crane was used to lift the machine off the truck and to gently set the machine down in a patio area located inside one of the buildings at Larry's manufacturing company.  Since three machines were unloaded from the truck by the crane, the crane cost for the 33,000 pound lathe was about $300.  Larry has 3 CNC milling machines and 10 CNC lathes at this location; and 3 manual milling machines, 15 manual lathes, and excellent welding equipment.

Why are gravity motors not in general use today for producing electricity and for powering cars and trucks?  Is it a conspiracy of the oil companies as some believe?  The answer is no.  Larry is part of the American Oil Industry as the number one producer of some of the parts used in oil well pumps, and Larry is aware of the moral, honest, socially responsible behavior of those who run the American Oil Industry.  American oil companies have been active in a number of alternative energy areas including wind energy, solar energy, and hydro-electric energy.  American oil companies are well-positioned to develop, promote, and profit from better ways of providing energy, and are leaders in bringing new technology to the nation for providing energy.

Larry believes the primary reason for gravity motors not being in general use today is because an individual has not led America to a better way of providing energy.  Henry Ford is the individual who led America to a better transportation system, and Bill Gates is the individual who led America to a better information system.

Current-day activity regarding gravity motors generally is more of a search

for gravity motor technology developed in previous centuries before the invention of the steam engine.  Based on manufacturing technology of the time, some of the best individuals created gravity motors that worked, but that were impractical because of the weight-to-power ratio.  For example, one of Bessler's wheels was 12 feet in diameter and weighed about 2000 pounds, and converted static force to about one horse power of dynamic force.  Working but impractical gravity motors of previous centuries were based on the leverage principle (weights at varying distances from the center going around the center of a circle).

Using a design of a rectangular path for a train of devices that change in weight per linear foot depending on the width of the track during the course of their movement in open air, Larry McCart has suggested that static force can be converted to useful dynamic force.  Vertical track like in the drawings or horizontal track like roller coaster track can be used; Larry believes horizontal track would be better.  Gravity motors in development at Larry's research and development center in Bakersfield, California, should lead to gravity motors useful for powering vehicles.