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 Posted: Mon May 15, 2006 5:54 am
Cynthia_Rosenweiss But what does it do? Your design looks an awful lot like a Perpetual Motion Machine. By "pedals" do you mean that you're going to link the magnets at the centre to bike pedals? In that case, are you trying to generate electricity from using the bike? That's impossible to do with the above design. Or to use the magnets to transmit the motive power to the wheels? In that case, there is already an invention that does that - the bicycle chain. As for the design aspects, the "repel" magnets face the "pedal" magnets directly, but the attraction forces operate perpendicularly. You would do better to make the central part the stator, with strong magnets, and the four corner magnets the weak ones. Make sure that the corner magnets are in rotatable mountings, and are geared so that when one end of a stator magnet is repulsed by like poles, the other end is attracted by opposite poles. (That is, when the rotor has gone through 1/4 of its cycle, each corner magnet in the rotor flips by 180 degrees) As the rotor spins, the internal gearing would align the rotor magnets automatically. That would make a better design (at least in the abstract), but if your idea is that of a PMM, then the improvements that I just suggested won't help you achieve perpetual motion any more than your original concept does. I don't think this thing is meant to do anything useful at the moment but spin. And if you flipped the internal magnets that would reverse the rotation. If you look on the pic (I'm sorry I really can't seen the thumbnail so I'll post a larger one) then you see that in the top lefthand corner the small manget's negative side is attracted to the top lefthand corner's positivive side. Once given a push (for it cannot act on its own) the negative will move towards the positive (and the positive away from the positive) and once it reaches its midpoint its velocity (which was given by its initial push) should be enough (or rather you have to make it enough) so that it passes this point and the magnet moves on to the second quadrant (or if you want in an x and y coordinate in the fourth quadrant) at which point it's positive repels the positive and the negative attracts the next outer positive magnet and the rod keeps spinning clockwise.  We don't know if it'll work, thought I think it's a good idea. Bruce lee is going to make one, I might make one, not until the end of the week though. We shall see...
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Posted: Mon May 15, 2006 4:46 pm
poweroutage I don't think this thing is meant to do anything useful at the moment but spin. And if you flipped the internal magnets that would reverse the rotation. Well, I'm not proposing flipping them in that way. Only to make it so that both corner magnets have a line-of-sight bead on the smaller magnets, instead of only one, and the other being perpendicular. Quote: If you look on the pic (I'm sorry I really can't seen the thumbnail so I'll post a larger one) then you see that in the top lefthand corner the small manget's negative side is attracted to the top lefthand corner's positivive side. Once given a push (for it cannot act on its own) the negative will move towards the positive (and the positive away from the positive) and once it reaches its midpoint its velocity (which was given by its initial push) should be enough (or rather you have to make it enough) so that it passes this point and the magnet moves on to the second quadrant (or if you want in an x and y coordinate in the fourth quadrant) at which point it's positive repels the positive and the negative attracts the next outer positive magnet and the rod keeps spinning clockwise. We don't know if it'll work, thought I think it's a good idea. Bruce lee is going to make one, I might make one, not until the end of the week though. We shall see... I still think he's come up with a PMM concept....
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Posted: Tue May 16, 2006 1:07 am
poweroutage I don't think this thing is meant to do anything useful at the moment but spin. Quote: But my fear with this project is that it wont spin fast enough or strong enough for its intended design, which is for a small helicopter. Tho i read something about Gears helping with Tourqe, or strength. If you need a clearer out look on things, let me know please, i would like to try and get this to work. So intended for use as an engine to power a helicopter rotor. However, you would really want some ways of, say, controlling it i.e. turning it on and off. If you still wanted to know about gears, let me recommend http://science.howstuffworks.com/gear.htmAnd finally, let me just mention, conservation of energy.
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Posted: Tue May 16, 2006 2:03 pm
Ah. So it is a perpetual motion machine, in that if left alone the machine would not stop spinning.
Okay. So it theoretically might not violate conservation laws in itself. The energy needed to get it going would be provided by pulling the rotor out of equilibrium.
Now all you have to do is worry about the thing which causes all perpetual motion machines to fail: friction and inefficient energy conversion. Your machine depends on having enough kinetic energy to get it across the equilibrium point on momentum alone. With friction constantly removing energy, this will not last forever.
Even if you're just trying to get it to spin, there will be energy loss from friction. Thus energy needs to come from somewhere, be it from outside or from the magnets themselves, which would cause them to demagnetize.
On the other hand, depending on how well you build it, it could be a good idea for a motor that is only supposed to spin for a short while, although rather pointless as there are cheaper, more efficient ways to build such motors.
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Posted: Wed May 17, 2006 4:28 am
Haha and at last, i didnt intend on turning it off, just to give me something to stare at with extream bordem.
Tho i have never heard of magnets De-magnitizing, course im not that far along in school and so...
Cynthia, Yes, bruce_lee meant for this to be a PMM. Thats what this intire thread is about, course creating electricity wouldnt be a bad idea with this... but alas, im drifting from topic.
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Posted: Thu May 18, 2006 7:36 pm
Dryfolius Haha and at last, i didnt intend on turning it off, just to give me something to stare at with extream bordem. Tho i have never heard of magnets De-magnitizing, course im not that far along in school and so... Cynthia, Yes, bruce_lee meant for this to be a PMM. Thats what this intire thread is about, course creating electricity wouldnt be a bad idea with this... but alas, im drifting from topic. Um...the reason people keep bringing up the whole PMM thing is that PMMs are impossible. They're a violation of thermodynamics in that they assume 100% efficient energy conversion and 0 energy leakage, both of which are violations of the 2nd law of thermodynamics. Unless you constantly add energy, which you are not doing by design, or find some way to channel the entropy, which you're not doing because it's much too difficult, this machine will run out of energy eventually. Thus what you're doing is futile. As for magnets demagnetizing, it actually makes a lot of sense if you think about it: magnets are made of tiny magnetic domains that, in a magnet, all point in the same direction. Entropy tries to get them to go in different directions because that is more chaotic; only the stored energy inside a magnet keeps them pointed in the same direction. Once you start eating at that energy, which is what your machine would do, the entropy wins and the domains go in different directions, which, since the domains are now interfering destructively instead of constructively, demagnetizes your magnet.
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Posted: Tue Mar 13, 2007 8:35 am
THe diagram neglects the - poles on the outer magnets, which will prevent the magnetic field lines from tracing a circular path (which is what you need if you want this to work. If you let this system go from rest, it would move 45 degrees counterclockwise, till the magnets were as close as possible to a pair of cylendar magnets, and stop. [edit]-Whoah? This thread is OLD! oops
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Posted: Tue Sep 15, 2009 5:41 pm
I think a device like that could yield some use. However only by the fact that it isn't a perpetual energy device, but rather a low energy input device.
Even if the energy isn't perpetual, it could be a lot more productive to have a hand crank design where a single "push" could rotate the object say 100 times. So no it's impossible to have a constantly spinning device due to the loss of energy and the dispersion of it, however I think it could be a very good energy recycling unit, though I have no math nor experimenting to prove this...
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