Thread: magnetic motor problems (i know, not another one "groan"... lol)

Firstoff I just wanted to clarify that this a question that has plagued me for manyyears, and i do have a fairly decent grasp of physics ( My original major atuniversity was mechanical engineering before I ended up transferring tobusiness, so i never got past first year physics). I understand the laws ofconservation of energy and thermodynamics and i abandon this project many yearsago. But there are some details that haunt me to this day and i'd like to findsome closure.

Many years ago, when i was 17 I had an idea for a motor that ran off of aconfiguration of permenent magnets, having never heard of perpetual motionmachines i wasn't aware of the problems with this idea. After a lot ofexperimentation and trial and error i built a prototype from wood and largeceramic speaker magnets cut into 3 equal sized sections making six sections in totalwith one ceramic magnet positioned between them attached to a central driveshaft. The concept was akin to a magnetic rail gun curved back in on itself, usingvery particular alignments of the poles. As you can guess it didn't work!.. Bigsurprise right!... lol... I realized that the magnetic fields from each sectionwere interacting, so they were not acting as isolated sections which wasintegral to the concept. Being young and not knowing any better i tried to finda way to make each section act independently, and eventually i found a way. itseemed a ferrous iron plate placed between each section effectively (I don’tknow if it did, but it behaved as though it had) isolated and amplified the force acting on themagnet attached to the drive shaft. The effect was stark and it had asubstantial amount of torque. The next step for me was to design a system thatwould move these metal plates out of the way to allow the magnet to pass andthen return to place. This was about this time that i started at university,and it was this device that inspired me to major in engineering. However I quicklyabandon the project after learning that it essentially would violate the lawsof thermodynamics.

But to this day it haunts me. I've never found an answer that satisfactorilyexplains my observations, and explains exactly why it wouldn't work. Although idon't doubt that there is a reason that it won't, because if it did it would bea perpetual motion machine, Thereby creating energy from nothing, which isparamount to creating matter from nothing...

So I’m looking for the mechanism that explains why this won't work. Duringobservation it really looked like it did work. There was large amounts oftorque.. it easily traversed the gaps and spun freely under its own power. Themagnetic fields acted as though each section was independent. And I had foundthat I could counterbalance the iron doors so that they were very easy to slidein and out of the gaps between each section. (on a side note the doors seemedto become polarized themselves in such a way that it actually improved thepower of the unit rather than just isolating each section) Everything seemedvery promising.

The only thing i can think is that the magnets are actually demagnetizing as itruns and are therefore giving up the energy used to create them. Any insight?

I really appreciate your time in responding to this.
Maybe i can finally put this out of my mind once and for all.

Thanks a bunch
Mike

The forward motion (to insert) the ferrous iron create an eddy current (on the surface of ferrous iron) which cancel the magnetic force of the speaker magnets. The source of energy is in that 'insertion' action.

thanksmsafawn, that definitely answers some questions... still leaves some others.Just to clarify how this worked imagine a 10" speaker magnet cut into 3'sand glued to a mdf platform so that it is still a perfect circle with a smallgap between each section (about the width of the ceramic cutting blade used tocut the magnet in 3's. The north side is glued to the wood and the south sideis facing up, and above it is another identical speaker magnet, with its northglued to an identical platform so it's south is facing the other south. Thesmaller rectangular magnet the is attached to the drive shaft is positionedsuch that it's north and south run perpendicular to the north and south of thespeaker magnets. (the following were my observations) Now if an iron plate isplaced at the opening to one of these gaps it is pulled into the gap so that itis centered in the gap. yes if the drive shaft arm is not held it would give akick to the drive shaft. but even if you held it and let everything come to restit would begin spinning the moment u let it go. (found out the hard way that uneed to get your fingers out of the way. had a broken drive shaft arm and ablack and blue fingernail from that lesson).

Is this "insertion" energy conserved as potential energy in thesystem until the plate is removed? That would make some sense if that was thecase as i never did finish making this device, so i never did get around tocreating a cam system to move these plates as necessary, although i did placethem on a track (a grove in the wood) and counter balance them with a spring sothe force pulling them in remained small but constantly inward. It seemed to beproducing a lot of power but that could very well just be an illusion ofperception as i was still moving these doors out of the way by hand (i actuallyonly had one moveable door in place.. couldn't move my hands fast enough tomove each door as it past the other gaps, so during experimentation the othergaps were just resistance points.)
I’veoften suspected that both the observed effect and reason that it actually won’twork lies with these doors.
Is this "insertion" energy conserved as potential energy in the system until the plate is removed? That would make some sense if that was the case as i never did finish makeing this device, so i never did get around to creating a cam system to move these plates as nessesary, although i did place them on a trak (a grove in the wood) and counter balance them with a spring so the force pulling them in remaind small but constently inward. It seemd to be producing alot of power but that could very well just be an illusion of perception as i was still moving these doors out of the way by hand (i actually onlly had one moveable door in place.. couldn't move my hands fast enough to move each door as it past the other gaps, so during experimention the other gaps were just resistance points.)

I assume one could build a "motor" as you describe, in principle. Ignoring the refinement of moving the motors in and out, there are two ways energy will be lost: on is friction in the bearings, the other is currents induced by moving through the magnetic fields (this will be dissipated as heat). This loss of energy will cause the rotor to slow down and stop. Any attempt to extract useful work will just make it slow down even quicker.

You could reduce the friction by using some sort of magnetic suspension and running the thing in a vacuum. You could reduce eddy currents by a suitable choice of materials - perhaps superconductors would be required. But again any attempt to extract energy would cause it to stop.

Actually, I am not convinced that having the magnets in you system makes much practical difference. It is a bit like those pendulum "executive toys" with multiple magnets in the base. The magnets make the pendulum move around randomly but the pendulum will only swing for as long as it would have done without the magnets.

Your rotor will be getting equal pushes and pulls from the magnets.

Adding your mechanism to move the magnets in and out just adds another source of friction so any extra efficiency gained will be lost!

I just want to clarify again that i have no delusions that this device would actually work... energy is either potential or kinetic... and if you change potential to kenetic it is no longer potential, and if use that kenetic energy to draw energy out of the system the energy is gone from the system, so the idea of a device that can continue spining forever under load is rediculous.
just want to understand what i was looking at.

Thanks Strange.

I had considered that.. however, unlike the executive toys the force that arrose from it's arrangment automaticly started it spinning as there was no natural point of rest, (god i wish i had recorded this thing on video or something.. all i have is old drawings now) but it didn't need a "kick start". it simply had to be assembled. once assembled i just let go of the drive shaft arm and it took off...

Originally Posted by mikeransom

I just want to clarify again that i have no delusions that this device would actually work

Phew! That's a relief (given some of the posts you get on science sites!)

Originally Posted by mikeransom

unlike the executive toys the force that arrose from it's arrangment automaticly started it spinning as there was no natural point of rest, (god i wish i had recorded this thing on video or something.. all i have is old drawings now) but it didn't need a "kick start". it simply had to be assembled. once assembled i just let go of the drive shaft arm and it took off...

Interesting. Sounds like it didn't have a stable point of rest and was sufficiently low friction that the initial "fall" towards the nearest magnet was enough to kick start it.

Does anyone know if this set up would de-magnatize the magnets? I have a strong suspision that what i was oberving is the magnets acting as a kind of "battery" all be it a very innefitiant one, and that if it ran for any length of time the ceramic would become de-magnatized.

Haven't read anything about magnetism behaving as energy reservoir yet. This mechanism doesn't exist. Magnetic field only provide potential-field for object inside that field to convert its own energy into other form of energy, the potential-field doesn't store any of the object's energy... and couldn't feed the object with energy either.

Magnet-bar will reverse polarity when subjected to a strong opposite magnetic field (refer to: "magnetic Hysteresis") and will loose magnetism altogether when heated or dropped (for iron bar magnets). It shouldn't loose magnetism when contacting with other similar magnets...

Originally Posted by msafwan

Haven't read anything about magnetism behaving as energy reservoir yet. This mechanism doesn't exist. Magnetic field only provide potential-field for object inside that field to convert its own energy into other form of energy, the potential-field doesn't store any of the object's energy... and couldn't feed the object with energy either.

Magnet-bar will reverse polarity when subjected to a strong opposite magnetic field (refer to: "magnetic Hysteresis") and will loose magnetism altogether when heated or dropped (for iron bar magnets). It shouldn't loose magnetism when contacting with other similar magnets...

Thanks again msafwan; I do appreciate the input. That makes sense to me as well though as the the generated kinetic energy should come from the potential of the the two magnets within each others magnetic field as a relation to how far down the gradient the magnets can move before reaching a neutral position where the forces are balanced and work can no longer be completed. Like gravity, each object should retain the strength of its own field regardless of what other objects interacted with that field. I find that there is a common misconception that a gravitational or magnetic field is in and of itself a "energy field" of sorts that can be added to or taken away from, a bit of a logical fallacy if my understanding is correct (and it very well might be). Hmm.. the problem of what i observed still haunts me to this day... You were very right that it is the fall to lower potential that starts the motion.. just not quite sure why it seemed to continue to run.. i'm sure it must be that the energy does stem from the eddy current of the insertion of the metal plates, at this point i can't think of what else was causing this effect, and that the small amount off energy needed to cam these doors would be more than the energy that placing them creates. I might just build this thing again for shits and giggles... might be the only way to get a firm grasp on what was going on.

on a side note.. I know that there are answers for this thought experiment, and i'm hoping someone on here can answer. Just thinking about the nature of potential energy lets say there is a kieser belt object that gets bumped by another kieser belt object so that it is ejected at an angle out into space with a new velocity. The asteroid caries on through space with a constant velocity in a new vector conserving the energy of the initial impact. at some very distant time in the future, by chance it crosses paths with another asteroid that had been ejected from it's own solar system under similar circumstances. initially the two objects were so far apart and so unrelated in anyway that there was no interaction between either of them, and they were isolated systems as they traveled through space. however, chance put them on a collision course and after several million years their gravitational fields begin to interact and they seem to "gain" potential energy as they begin accelerating together, eventually colliding and amalgamating their mass and gravitational field strength. once amalgamated they should have a gravitational field equal to the sum of the 2 individual masses. so where did the potential energy come from, and (easier to answer, heat, sound ect) where did it go? does the energy mass system loose some mass in this process?? is there a provision in GR or SR for this? (i'm sure i'm just missing something very obvious here)

not trying to prove anything wrong here.. just the way my mind works, i can't help but look for examples that don't fit with my understanding of the way the universe works. Kinda like makeing sure i'm not wrong in my understanding. so that the truth as i understand it is as close to actual reality as is possible

Thanks again
Mike R

There is no mass missing in those scenario, but the scenario contain one inherent inaccuracy which may trick you to think there's new energy coming into the system. Here's what should happen:

An asteroid moving outside Sun's gravitational-well moving at an arbitraty CONSTANT speed "A", which by chance happen to "collide" into a gravitational-well of the Sun, which then gain speed as it goes into the gravitational-well, and then collide with a stable asteroid orbiting inside the gravitational-well, (assuming 100% Elastic collision) which propel outward the dormant asteroid into outward trajectory toward outside the gravitational-well, which travel at a DECREASING speed until it reach the border, and travel at a CONSTANT speed "A minus B" or "A plus B" or "A" (depend on collision angle)... which somehow collide with other "free" asteroid floating in space... causing the asteroid to melt (assuming 0% Elastic collision, 100% energy conversion) and amalgamate into 1 giant asteroid.

Where did the energy came from? from the first asteroid... ("An asteroid...")
Where did that asteroid get the CONSTANT speed "A"? from the Big-Bang...
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If 2 object collide with each other under an attactive forces: 2 things happen: it'll "stick" together and release energy, or it'll "bounce" like a pendulum bouncing on each other's balls ( Newton's Cradle - Incredible Science - YouTube :Newton's pendulum vid).