# Magnetic "shielding"

Hi, I'm working on a project, interested in your opinion
Need a material for magnetic "shielding"

There must be no repulsion or attraction between M1 and S since non of them is stationary and it would affect the motion. There will be a ferromagnetic material behind S that cannot be affected by the magnet until S opens.
S should be 0.5mm thick with an opening of 1 mm

I don't think I could use diamagnetic materials since the distance between M1 and S should be 0.1 to 0.2 mm and there might be some repulsion effect.

It needs to be like in picture 2 with no repulsion/attraction between M and S
The magnetic flux must reach the recuperator (ferromagnetic so it will attract it, while S open)
Do not propose electromagnets - can't use electricity on this one

Symmetry777

mfb
Mentor
There must be no repulsion or attraction between M1 and S since non of them is stationary and it would affect the motion.
I don't think this is possible. To act as shielding, S has to be influenced by the magnetic field, and this will always lead to forces.
Mu-metal is a common material for shielding, but then the geometry should be different.
Superconductors are (up to some field strength) ideal diamagnets and therefore great shields, but then you get a force between shield and magnet as well.

Symmetry777
So, in my device I need to control the magnetic flux of a permanent magnet using the kinetic force of the device, the permanent magnet will be in motion but it's flux can only access the recuperator once it's at 1mm of it, so my solution was to put something between them that would open once the magnet is close enough and close once it distances it again.
One of the conditions was not to use electricity. Otherwise it would be too easy
I'll figure out something

mfb
Mentor
What do you want to achieve with that setup? There could be alternative options with a different design.

I could use an electromagnet and the problem would be resolved but one of the conditions is not to use electricity, so I'm stuck with a permanent magnet
I just need to control it's flux, when the rec. will receive it and when not. So I only have some kinetic force to achieve this.
Shielding was the first thing to come to my mind but I just started working on it and it seemed a little problematic so I started this post.
If you have any ideas I welcome them

Low-Q
Gold Member
Magnetism is not possible to shield as you want it to. You must apply energy to do so. A coil around a permanent magnet could make an opposite magnetic field. If it WAS possible to do it the way you want it to, everyone could make themself a motor that is "powered" by controlling the force between permanent magnets without energy supply.

And as you sure know, energy cannot be created from nothing. Only transfer from one form to another.

Vidar

berkeman
Mentor

(Looks like we Mentors are piling on in this thread...) :-)

Thread re-opened for now. If we find out you are trying to get help with a PMM or over-unity device, this thread will be closed for good.

mfb
Mentor
@MXM13: See X-Y-question. What is the problem you want to solve with that concept?

By the way:
Until yesterday, every physicist was laughing at this engine and its inventor, Roger Shawyer.
And we still do.

Edit: Sorry berkeman, didn't see your post.

Low-Q
Baluncore