Visionary

Yes I did read the second line on that post. I think regardless of the direction of the field, the eddy currents would tend to oppose the change Look here. The magnet is attracted to the ferromagnetic surface, The black arrow represents the force applied to move it around the surface. The green arrow represents the eddy currents induced to oppose the change I think? It's like sliding a magnet over a copper plate it you do it quite fast, you'd feel a repulsive force I guess? Well, I knew that. In fact, it could be less when lubricant is applied! Much much more less. But the issue now is with Eddy currents. Btw, Thanks for all your help!

Could you explain that point a bit more? And what machine do you mean?

When sliding a magnet rapidly around a ferromagnetic's surface eddy currents are generated since all ferromagnetic materials are all conductors. I agree, by increasing the resistance we reduce the eddy currents, My idea is having small air gaps in the ferromagnetic surface. By doing so, it reduces the eddy currents significantly, thus having a low induction force.

What do you all think? Is it possible to have a ferromagnetic material that is shaped like what's above, and not generate the eddy currents? I want to figure out methods to reduce the eddy currents, any suggestions?

I'd like to make the eddy currents really low, in fact, a value near zero. So I think by having such a ferromagnetic material shield like so: The eddy currents decrease so it would not be a problem. However, the magnetic force decreased due to the change. It could be possibly increased by increasing thickness or the diameter?

Well I was more interesting in knowing the magnitude of the induction force in comparison of the attraction force between a magnet and a steel plate for example, but now... After knowing its possible to reduce such a force by creating air gaps so that the eddy currents would have to pass through small tiny gaps of air, since air has a very large resistance the eddy currents are reduced's substantially regardless of how fast that movement was. So the attraction force now, could be x while the eddy current's induction force is less than x due to the air gaps. I'm trying to reduce the eddy currents between a magnet+ferromagnetic materials without increasing heat as you all know that would cause a huge damp to the magnetic properties of such materials.

It's strange how you can have both magnetic attraction and eddy currents at the same time while sliding a magnet around a ferromagnetic surface, I assume the force can never ever be close to the pull force not even 1% of it. Since it's force is the function of the "change" of the magnetic field. Also, Faraday's law of induction is used to calculate the eddy currents?

Good point Studiot, What about the eddy currents generated to oppose the change in the magnetic field when sliding a magnet off a steel plate?

Greetings, I noticed that it takes less force to slide a magnet off a magnetic object(magnet/ferromagnetic material) than directly pulling it off? The force needed to pull the magnet off could be 10LB while the force applied sliding the magnet off is 1 or less LB, only force countering the applied force is friction not magnetic... Why is that? I even noticed that only at the edge, there is a stronger force, but not as strong as the direct pull force.

Larger coil area same current. Thus, equal magnetic field strength + flux density. It's possible to increase the core size to decrease the quick saturation at the same applied current + field + flux density. Only thing that changed now... The rate of saturation change is much slower.

Well, in case of the electromagnet using a Mu-metal core is great, but the only problem was saturation. I suggested increasing the thickness or area of the core in order for it to handle more of the applied external magnetic field of the coil to create a higher total magnetic field. If we made the coil bigger but with the same current(I)...There is more area for the flux lines to pass through before saturating, and more electron spins for it to be aligned, causing a greater total magnetic field to be created by those aligned electrons + the magnetic field of the coil. So there is possibly an advantage, lowering the saturation rate for it to handle the applied magnetic field, and possibly increasing the magnetic flux lines due to the presence of more domain's(i.e electron spins) possibly not differently. So now I guess the saturation issue is solved .

No no no... Changing the area allows more FLUX from the external field to pass. A source. Turn's out... When they use Mu-metal shields its important to increase length and thickness why is that? Well, to allow more of the external magnetic field to penetrate the material. Assuming that if a materiel saturates rapidly because of all the moments being alined... Increasing the "size" would mean more moments have to be alined which means, a higher saturation. I read multiple resource that deal with magnetic fields, when using a certain ferromagnet to shield/test a field. The material has to withstand the magnetic field fully(i.e covers its total flux's). Hope that made sense.

By increasing the area we allow more flux to pass, I don't understand how increasing the total size of the Mu-metal will not solve the saturation problem. I understand that making the coil bigger( thicker wire or more turns) and I is the same hence B is the same. In reality, there is a limit to everything. In all electromagnets there has to be a limit. The limit of how much current we can apply is fine with me, the point that I'm emphasizing, is the fact the magnetic field from the coil is amplified by the thousands with a core. If Mu-metal is the core its could potentially increase the magnetic field by the ten's of thousands. "The saturation point is the flux density at which the material can not contain any more magnetic flux. Steel saturates around 22,000 Gauss, while MuMetal saturates at about 8,000 Gauss." I think the larger the material the more flux lines it should contain. Only if the surface area where the flux lines penetrate is increase, only then can the saturation change. Just got to solve the saturation problem and Mu-Metal could be used in stronger magnetic fields. Relative permeability: 20,000+ I have got to use this! It can amplify a magnetic field x20,000 times! What are the best known cores?

I know that it's a problem, but never understood why... Even if it did saturate really quick whys is it a problem? By increasing the size of the core maybe it can withstand a greater external field without saturating quickly, also by limiting external B of course it could help too. Mu-metal's permeability is above the thousands, in fact! Could be in the tens of thousands, adding its B + External B = a total B far more greater than Ext.B which is amazing, mu® is very very high that's why I'm trying to create a possible way to use Mu-metal cores,is it impossible? Or possible but very complicated?

It would probably be very very expensive. You're better off putting a human with a diamagnetic material, or a superconductor and do some awesome things

Um... Anyone has an idea about this?

Can Mu-Metal be used as a core for an electromagnet? It has a very very high relative permeability, good advantage! And other wonderful properties, what problems could it cause if ti was indeed a core for an electromagnet? Unfortunately, it saturates a very low fields, how can this be solved? By increasing the size maybe? V.