Quote from: Fred Flintstone on February 13, 2009, 11:11:03 AM
TinselKoala ~ I ask this in all seriousness. Do you think there is any way that a gravity wheel could work?  Obviously not with the same old "put a weight here and there and a few levers". I mean something with ingredients other than weight and gravity - something that has momentum, inertia, centrifugal forces, etc, that when working together cause the movement?  Personally, I feel that it is possible but all those pursuing gravity wheels are typically repeating the same mistakes over and over just like you said. I for one enjoy your critiques because it saves me time building something that is bound for failure.  I remember you took the time to build Mondrasek's gravity/magnet wheel so you must have had a slight hope it would work....or maybe you were just proving that it wouldn't. 

I actually don't.
Unless a way is found to put the wheel in a non-uniform field, and even then probably not. The root of my disbelief has to do with the "nature" of gravity. It seems that many people believe it's a force, but it isn't. It's an acceleration. Gravity doesn't "flow" any more than a road goes somewhere. It simply is, and masses can move along gravitational gradients, like cars move along a road. You can no more extract energy from gravity, in the usual sense and in a uniform field region, than you can get a "journey" out of a road. I know the analogy isn't perfect, so don't bother picking it apart. But consider the exact equivalence of gravity and "ordinary" acceleration. You prove the identity every time you ride in a car, because the accelerations from the car's motion (slowing down, speeding up, going around curves, etc.) add smoothly and completely with the acceleration of gravity according to the rules of vector mathematics, with nothing left out or left over. Now, it's clear to most people that you can't get "free energy" out of accelerations due to motion...I think.
So for a "gravity" wheel to work, there must be something, that is usually conserved, made to change. Like charge, or mass, or the gravitational constant. Changing moment arms or paths, in a cyclical manner, isn't going to do it. Losses can be made very small, but unless there's some change in a normally-conserved quantity the losses will cause the system to stop.

@sloth

TinselKoala pointed out the main problem. So, no go....
Actually, your modifications (ramps) to the original (at least 500 years old  curved compartments rolling ball wheel) is making things even worse... Why?

Think about:
-Most of the weights are (most of the time) "resting" on the inclined ramps, so they mostly don't contribute much to the wheel's rotation...
-the combined center of mass for all the weights is always below the axle...
-the "scissors effect" (many weights are "caught" between the curved path/ramp "jaws") - a lot of friction...

Can you explain which way this wheel is supposed to rotate? I see both ccw/cw arrows...

Anyway, if you'd build it, you would see for yourself...
Due to many flaws, it would probably not be moving at all....Just IMHO, of course....
Cheers!

Spinner,

Thank you for your analysis. It was much more informative than TinselKoala's canned answers, senseless belittling, and juvenile self-glorification.

To answer your question about the arrows, they represent which direction each weight should be pushing the wheel. Most of them are directed counterclockwise. Two of them push the wheel clockwise, and one has no effect either way in its current position.

The idea is that the wheel clearly has more weights pushing counterclockwise than clockwise. In a simple universe you'd think that alone would make it spin. However, the devil is in the details. My biggest worry about the design has always been that the weight of the counterclockwise weights will be lost by resting on the ramps like you said, but since I'm not a physicist I don't know how to calculate that loss. Hence me asking for help.

I suspect the problem of friction caused by the weights jamming against the spokes could possibly be lessened by using a rolling pin shaped weight with wheels at the end that rest on ramps outside of the wheel with the rolling pin sticking through the space between the spokes. If the wheels can spin independent of the rolling pin segment that makes contact with the spokes it shouldn't jam as much. If the surface of the spoke were to have a sliding track that moves with the rolling pin when it presses against it you might be able to reduce the jamming even more. Neither modification will completely eliminate friction. In fact, they may produce more friction just in a different way. 

So the situation is like this. You've got 9 weights resting on ramps pushing counterclockwise against the full weight of 2-3 weights pushing clockwise + friction + the weight of the wheel (which we'll assume is made out of as light of a material as possible). Without relying on vague, canned answers, it would be interesting to know how many resting weights equal one free weight and how much friction would have to be reduced to make the design more viable.

Any nonjudgmental suggestions are welcome.

Hi, sloth!
Thanks for the good words...  But..
My post was just a small addition to TinselKoala's.

He pointed out the main problem to you... Although you may think his post is a "senseless belittling", it still is correct.


Gravity wheels  are a long known subject. So, it's almost impossible to expect a nonjudgmental suggestions / answers...

Sorry to say, but I don't see anything which would make your concept workable.
Anyway, good luck!

Sincerely!

The ramps just add more losses.