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the overbalanced wheel

 
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in one of my many cruising youtube sessions I came across (again) perpetual motion type machines (which I have seen many forms of) and ran across the concept of the overbalanced wheel. Today I found this idea which is close to something that I think would work, to turn gravity into motion that can be harnessed as electrical energy, the idea being that the force created is much in excess to friction and any forces required internal to the machine. This idea uses hydraulics to swing arms to create the overbalanced wheel. Figuring someone better than I at geometry could come up with a linkage to get the arms to oscillate in the right way to get this to work without hydraulics.



 
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This idea dates back to the 8th century. But it doesn't work.

The Shifting-Mass Overbalanced Wheel -- Why It Isn't Perpetual Motion


Overbalanced wheels are of little interest to the physicist, for physicists understand, from many well-established laws and many lines of argument, that even if there were such a thing as perpetual motion, this is certainly not the way to achieve it.

All of these wheels use geometric design or mechanical devices to shift mass to a larger radius from the wheel's axle.

...

Perpetual motion wheels are invariably cyclic, that is, all motions of the wheel and its parts are repeated exactly during each complete revolution. So if a weight moves to a larger radius once per cycle, it must also be pulled back to the original radius later during the cycle. The work done in changing the radius by a certain amount from large to small is equal and opposite to the work done in changing the radius by the same amount from small to large. We gain no net energy per cycle.

Now imagine such a rotation in a vertical plane, so that gravity can play a role. Since the wheel's motion is cyclic, and the motion of the mass is cyclic, the work done on the mass by gravity as the mass moves down is of equal size to the work it does against gravity moving back up. There's no gain in net energy per cycle.

One of the most fundamental and well-tested facts of physics is that forces combine by vector addition. [This is sometimes called the "superposition principle" of force.] When two forces act on a body simultaneously, the net effect on the body is simply the vector sum of the forces. From this follows the result that when two forces do work on a body, the net work done on that body is the same as the work done by the vector sum of those forces.

We have seen that the radially shifting mass alone does no net work on the wheel during each cycle. We have also seen that gravitational force does no net work on the wheel or the mass during each cycle. So the two processes acting together will do no net work on the wheel during each cycle.

This is an outline of the reasons why physicists understand that all overbalanced wheels, no matter how ingeniously constructed, can never provide more energy than they were given initially. In fact, the situation is even worse, for the more ingenious and complex is the mechanism for maintaining the overbalance, the more poorly the wheel will perform due to mechanical inefficiency.

 
John Master
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This is an element I am figuring would need to be incorporated to make something like this feasible. Gravity pulls objects toward earth, finding another free/constant/natural force that acts in the opposite direction (in this case buoyancy) to raise the object would eliminate the need for the wheel to lift it's own weight back up on the up stroke. I also don't think anything like this could be successful on a desk model size scale as the length of the stroke will determine a lot about how well it would work. Perhaps what I am envisioning is not exactly an "overbalanced wheel" but more of a "gravity harvester" of sorts. With a waterwheel you have a free supply of "objects" falling in the form of water. Trying to find a solution for people like me who don't live by a river or whose river has no head to benefit from.




 
John Master
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pretty much every version of an "overbalanced wheel" I have seen on youtube either doesn't work or has a motor hidden in the base, some more cleverly than others.
 
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They don't just "not work", they can't work, because they would require energy to come out of nothing. If there is no energy input (and gravity is not an input by itself), there can be no output. Lots of people have tried to out-clever themselves and get something for nothing, but plausible-sounding logic has a way of running into reality.
 
Glenn Herbert
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The buoyancy effect in that video does not come free; unless you have a source of new water to feed into the weight at the top and drain the weight at the bottom, you will have to pump the air into the weight, which will push that amount of water up. You are either using water power or some pump power, and if you calculate the energy required for pumping or coming from water falling, you will find that it is a bit more than the energy you get from the weight going down.
 
Glenn Herbert
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I don't mean to tell you what you are not allowed to try, but physics is not a matter of opinion; there are laws which have been found to be universally applicable in our frame of reference, in spite of many thousands of intelligent people trying to circumvent them.
 
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Yeah the link that Dan posted pretty much says it all. It ain't going to work. If it could then we would also have perpetually bouncing balls going all over the place. Now that sounds fun.
 
Zach Muller
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I actually do believe "something from nothing" could happen apparently, but no laws of physics would be broken. Humans would come to understand the fundamentals of physical life on a quantum level.
 
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John Master wrote:Perhaps what I am envisioning is not exactly an "overbalanced wheel" but more of a "gravity harvester" of sorts. With a waterwheel you have a free supply of "objects" falling in the form of water. Trying to find a solution for people like me who don't live by a river or whose river has no head to benefit from.


Unfortunately, there is only one type of gravity harvester that actually works, but the good news is that they work so well that all the energy we have on the earth comes from gravity harvesters.
 
John Master
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i am not saying to break laws of physics, I am trying to say, combine two opposing natural physical elements into a machine that produces usable energy from them. one thing you find is the farther you take an inverted cup under water the harder it pushes back up. I am going to tinker tonight with ideas more along the lines of the second video and less of the first video. I get what you are saying about the overbalanced wheel not working as most people present it.
 
Glenn Herbert
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Have fun playing, but keep in the back of your mind that such devices which do not harvest actually moving mass or energy cannot ever work.
 
Dan Boone
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I probably screwed up by responding to this thread, and it's now fairly clear to me that I didn't do a good job in my response of leaving room for other people's ideas, which is one of the goals here at Permies. I did try to "be nice" (another rule here) but how nice could I actually have been when I was delivering what amounted to a flat verdict that the proposed idea can't work? John, I apologize for that.

However, the thread needs to be locked. Because my failure illustrates what happens over and over in these perpetual-motion type threads. The "here are the physics" people and the "I think I see a way" people always wind up in hardened opposition (not leaving room for each other's ideas) and then being nice swiftly becomes a casualty. If you squint you can already see the sarcasm and dismissive phrasings starting to creep into the thread. It's time to close it. Thanks for understanding!
 
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