Calculating Electromagnetic Force between Two Magnets for Disc Holding

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Calculating the electromagnetic force between two magnets is complex and depends on specific details of the setup, including material constants and geometry. A rough example suggests that 1 kAmpere of current can exert 1 kNewton of force, but accurate calculations require detailed modeling and possibly numerical simulations. Online calculators may not provide reliable estimates due to the intricacies involved. Measuring force through a small model and scaling results is recommended, especially when dealing with high currents that generate significant heat. Using permanent magnets alongside electromagnets can be a practical solution for holding metallic discs together while allowing for easy swapping.
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hello

I want to calculate the force exerted between two electromagnets, based on their current

I want to hold two metallic discs together, how much force can I exert between them with electromagnetism?

is this something simple?

any hint?

thanks!
 
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Those calculations are complicated, and the result will depend on many details of the setup.
 
mfb said:
Those calculations are complicated, and the result will depend on many details of the setup.
can you give me an example at least?
for example electrical current 1kAmpere is required to exert a force of 1kNewton
isn't there an online calculator, simulator to play with?
 
Last edited:
physior said:
for example electrical current 1kAmpere is required to exert a force of 1kNewton
If it would be that easy it would not be complicated. You'll need a detailed 3D model of your setup, various material constants, probably numerical simulations in two or three dimensions and so on.
There is no way to even make a rough approximation without knowing how your setup looks like, and that's not something you can feed into an online tool in general.

It can be easier to just measure it.
 
physior said:
can you give me an example at least?
for example electrical current 1kAmpere is required to exert a force of 1kNewton
isn't there an online calculator, simulator to play with?
Build a small model, take measurements, then scale it up. If it will involve large currents for long durations, then heating of the electromagnet is going to be a major factor.

An alternative might be to use powerful permanent magnets to hold things together long term, with an electromagnet to briefly oppose the field of the Neodymium Magnets so the discs can be swapped in/out. Try to avoid mechanically jarring permanent magnets, that can eventually weaken them, I believe. It might be feasible to slowly power down the electromagnet so that it cushions any slamming together of the neodymiums. :)

Is this along the lines of a thought experiment, or do you have a real-world problem to solve?
 
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