Selecting Materials for Magnetic Shielding

<...purpose is to decrease resistance between two magnets repelling eachother when in close proximity...>

So long as it isn't for an over-unity energy device then that's OK.

as ive been told an over-unity device is impossible, so why youd bring it up idk.... but what if it were for such a contraption? would you deny me such information based on your bias that i am destined to fail? would the incandescent lightbulb have been produced if tom believed there were devils in the wires. of coarse but it would have been a major setbak for several years.

so... can you point me in the right direction of a dense material that re-directs magnetic flux or will i be forced to wind up my motor with a giant spring?

A dense material that redirects magnetic flux is iron, or one of it's analogues. There are no magnetic field insulators in the ordinary sense of the word. A simple work through of Maxwell's equations will show that to be the case.

and there is nothing else as effective as iron? no liquid, or poor metal, anything that isnt as strongly attracted to magnets. for instance a piece of titanium or alluminum or nickel with iron impurities in it. I dont require full saturation. the material needs to move while exposed to magnetism, iron does not move well at all while in the pressance of a magnetic field, which is why im trying to avoid it.

OR.... should i just place a thin coil of copper encased in Al between the two magnets, and use a 3rd magnetic field to block the apposing magnets during the time they are in close proximity, id like to not resort to electromagnets if it can be avoided.

its my last step in a greater efficiency gizmo... electro magnets are my fall back, but a 75% shielding substance would work even better.

I suppose, in a sense, I misspoke when I said there are no magnetic field insulators. I imagine you might have been asking about a magnetic flux insulator? That would be a different story and air makes a very good one.

But, anyway, aluminum moves when exposed to a time-varying magnetic field. Titanium really does not more than a skinch. Many nickel alloys move a lot. But, I thought you were trying to shield something.

I too tried this but it seems it does not exist, yet. I suppose otherwise electric motors could be built lot lighter (not piezzo-motors). Currently magnetic energy storing materials are pretty heavy and all seem have iron in them.

There are a lot of materials which can exhibit magnetic properties when current flows in them but being attracted by a magnetic field as much as metals with Fe in them I really do not know.

If you ever find something relevant let me know because I would be very interested myself!

Which is moving - the magnetic field or the shield and how fast? Can there be a phase shift?

mu Metal is an alternative to iron but is very expensive, Google it and you should find products such as CRT shields which I have used with some degree of success.

As far as I know there are no purely non metallic materials; unless some one has re-done the Maxwell equations lately

Try imaginarium or unobtanium. They are perfect for your project...

I don't claim to understand what you're trying to do here, but, I do think that all the claims that it's not possible are wrong. Take an old hard disk drive apart: the two magnets which are used along with a coil to control the position of the read write head are incredibly strong and are glued to pieces of metal which seem to do exactly what you need. I always believed they were mu metal, but, don't know what that means.

The hard drive. This material does a very good job of distorting the field of the magnet but is also very attracted to the magnet. If you can find a source for this material please let me know. nick@dogflag.net

Thanks! I completely failed to notice that he was hoping to achieve this with a material that was not itself affected by the magnets.

thank you all, I received a good chuckle with the imaginarium shtik...

Two magnets, one stationary. Magnet on the right is moving towards the unknown material in the middle. either iron, mu-metal, or some sort of magnetic shielding. ideally it is oblivious to the magnet on the other side of said material. soon as the moving magnet approaches within a few Cm's of the material, the material needs to move, upward works best. this then exposes both magnets to each other, they repel, the stationary magnet does not move, the other travels away.

This is what my purpose of this information will be used for. Iron is extremely attracted to magnets, making it difficult to remove from a magnets vicinity quickly. If i can not find a material with less magnetic attraction with similar shielding capabilities I will revert to plan B and place an electro magnet between the two. when turned on the magnets will attract to the middle, when turned off they will feel the like poles and repel.

those of you whom claim to be far more intelligent then me, tell me I'm wrong. I will gladly admit defeat and revise my gizmo. I am a scientist and try to hold no bias.

Please, any suggestions and criticism is encouraged.

Outisde a dog a book is mans best friend, Inside a dog is too dark to read- Groucho Marx

You're the smartest bloke I ever encountered in this field. I asked you a few questions before but now I can see your concern and frankly over 4 years ago this is exactly the trap I got into and came to a halt since.

the Mu metal is more for electro-static shielding that you can find on the CRTs of just about every test equipment as they use for deflection that principle as opposed to TV CRTs which use electro-magnetic.

I forgot the reasons and specs about its use but I am almost dead sure you will never be able to use it like that.

Magnetic shielding is always done with iron based metal that is heavy and obviously attracted by magnet. Good shielding is about being able to dissipate all the energy of the magnet i.e. shunt it by the metal shield, or cancel it out by an electro-magnet you're talking about which again require energy. (Definitely not the best method to create the perpetual motion with!!! Just joking.)

thank you very kindly, even if im forced to use electro magnets, the input would still be half of the output... now before anyone throws a science book at me and reports quantum heressy, because soon as i turn off the electro magnet the two magnets would repel, say the magnets have 90 lbs of force exertion... a relatively small amount of electricity would be required to attract the magnet with an electro magnet, giving me motion in one direction, then like a pendulum when power ceases, the magnets repel and give me the other half of the power in the opposite direction untill the electromagnet is turned back on pulling it back. not free energy, but cheaper. at least 200% output. the expense would then be in replacing over heated wires and other instruments of long periods of use. if a proper shield would be in place then i could make it completely free.

Pay attention to marcot - he speaks the truth.

Back to the discussion, however. You asked about a shield that worked similarly to an insulator. And, I don't think there is such a thing for a magnetic field. The effective passive shields for magnetic fields are magnetic conductors, not insulators.

The key to seeing this problem is understanding that you will create a strain in the magnetic field as you shield one of the magnets. Without getting too long-winded, that strain will be non-conservative. The area of the on/off cycle will represent work and will exceed whatever you get out of the pendulum.

Get a horseshoe magnet. Now shield the poles by putting a keeper across them. Now unshield one of them by sliding the keeper. Notice how much effort it takes. That's your problem.

yes ive known this to be the problem long before i even suggested it. I have a couple solutions but they take precision that im working on. id like a nickel iron alloy, or something similar that allows 10% of the magnetism through, that way the magnets do not get close enough to the iron shield to connect.

I plan to use a lever attached to the sheet of iron, and use the force of the magnet pulling itselft toward the piece of iron to push the lever and this would pull the iron shield up and away from direct contact with both magnets.

if the force of the magnetic attraction to the iron shield is too strong and i can not find a slightly less magnetic alloy of iron or other substance, i will implement electro magnets, making it a pulse motor.

either way, i have the means to create renewable energy, so far not commercialy viable, but it has its benefits so far as a light source when im up late at night tinkering.

which has a more fluid distribution of mechanical energy? gears, chains, or belts, perhaps a mix?

could condensed air or a gas also work to help shield either the iron or the magnets themselves.

The force from a permanent magnet being attracted to a piece of iron cannot be enough to push the iron further away. There is no available energy in a magnet, so the only energy it ever has is a potential energy of position which has to be provided by an outside agency. With that potential energy, a magnet can do one-time work but cannot cycle through and repeat.

ok, so ill have to add energy just to move the shield, maybe a large spring or a tiny solenoid.

I thought of using a gentle spring operating in its linear range but still came to a halt at the time because the shield issue. However, with some further ideas I might have been able to come up with the desired result but I had to put it aside.

By varying the thickness of the shield or the distance between it and the magnets can also help!

Can you explain this over heated wires?

What level of energy you talking about?

You can email me privately if you like and can vent ourselves on this topic.

free energy motor work

does anyone have specs on "Aerogel" ? i cant find too much info on it. i doubt it can serve my purpose but im curious. its silicon dioxide i think, theres also seagel

pressurized mercury, or mercury gas, good conductor with low electron affinity, any suggestions how i could test any possible magnetic shielding it might posses.

how well would ferrofluid and murcury mix, would it be like oil and water or water and salt.

naw, i think seagel is still a mere lab experiment and hasnt been made readily available, could be wrong tho, but it might be overkill. for a room temperature motor Aerogel might even be overkill.

By chance would anyone know a rating system of magnet strengths? for example how many windings and volts are required to match the strength of an average permanent magnet. im sure its measured in ohms. it would be nice if I could find a way to match the strength of an electro magnet to the surface area of a permanent magnet.

While what you are attempting to do with permanent magnets basically can't be done.

There is still hope.

Nicolov Tesla patented a method of winding magnetic coils in which the inductance and capacitance of the coil could be controlled by the method of winding. You will have to do your own research but basicly the method is today known as a bifillar wind or caduces coil. With modern electronic switching you can do some amazing things with this, win bets with people like those in this forum and possibly produce some useful results in terms of high efficiency battery operated motors. Tesla did, he drove a battery powered car around town for a couple weeks once. Nothing left of the battery when he was done though, sigh...

If your stuck on magnetic motors Penderov's design is easily reproducable and demonstrated to work. No on off switch though, sigh...

If you want to research or study magnetic flux switching devices then you need to be aware that the fly in the soup for your approach, and most others, is called the Lentz effect. Lentz effects are created by eddy currents or induced currents in motors and transformers and such.

Because they are induced there is a slight time lag between the formation of the driving flux, the induced currents, and the reactance or Lentz flux and the reactance or Lentz currents. This time lag can be exploited by various means including magnetic flux switching devices, although I am not aware of any like what you propose that have actually worked.

Bottom line is, no free lunch served at this cafateria.

Research like this did lead the Japanese to develop the extremely high efficiency motors that we all use in portable drills and such. They were apparently less impeded by the prejudice of their collegues and went ahead and did what western engineers are incapable of because they are still certain it can't be done.

Same for variable speed controllers for industrial motors. The japanese dominate because they have a superior understanding of both theory and practice. So, don't be too discouraged by anything you read here, keep asking questions, even if others think you are dumb to do so, and if you do discover something, first try and figure out why it works, then try and use it to produce something useful.

As for Maxwell's equations, the ones that TVP45 mentions. The ones in common use today were actually developed by Heavyside and are not Maxwell's. Maxwell's original equations are in qauternion form and actually can produce subtly different solutions to some problems than Heavysides, particularly in modelling magnetics. You do not seem to be inclind toward heavy math so you may prefer to continue to experiment more than calculate, but, still do the research and if you ever want to be able to explain your results, assuming you obtain some, you will have to study the theory as well.

Best wishes,

Mr. Gee

"As for Maxwell's equations, the ones that TVP45 mentions. The ones in common use today were actually developed by Heavyside and are not Maxwell's. Maxwell's original equations are in qauternion form and actually can produce subtly different solutions to some problems than Heavysides, particularly in modelling magnetics. You do not seem to be inclind toward heavy math so you may prefer to continue to experiment more than calculate, but, still do the research and if you ever want to be able to explain your results, assuming you obtain some, you will have to study the theory as well."

Dadburn! What a fool I've been! Imagine my folly in believing some old goof like John David Jackson when I could have learned the true truth from Mr. Gee. Next I'll probably find out Newton never wrote Newton's laws? Or that James I didn't write the Bible. Will wonders never cease?

BTW, the gentleman's name was Heaviside.

My apologies.

Mr. Gee

Mine, too.

Quite some time ago I was involved in some exotic research that demonstrated a shielding effect from polyethylene plastic. The shielding was NOT specifically magnetic, but it was a very strong and measurable effect none the less. Since I can not state positively that this material will not work in your application I can a do say, it might be worth a try.