We are looking to create a fairly small 10-20lb electromagnet. What we need this to be able to do is create down force from a range of say 3-4 feet.So when holding the magnet at around 3 feet it could create 20+ pounds of pull towards the metal sheet below(for a total pull of 40+lbs assuming the magnet itself is 20lbs). Just curious if this would be possible in the scale that is needed. We could pretty easily do the reverse and have the electromagnet at the bottom and the metal being pulled to the magnet but this is just not as practical for our project.

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Nathalie Foster · Accepted Answer

The size of a magnetic field is on the order of the size of the magnet that creates it. You can focus the field so that it comes out one side of the magnet, but once the field emerges into air it will immediately spread out in order to minimize its energy. For example, it&#039;s impossible to make a magnetic jet that throws a magnetic field like a hose.All that said, you only specified the weight of the electromagnet, not its size. So, if you had a large (but light) coil, several feet in diameter, you might be able to get a significant magnetic field at a distance of 3 feet. Doesn&#039;t seem likely to me that you&#039;d get a 20 pound pull from it, though.

We are looking to create a fairly small 10-20lb electromagnet.What need to down from range 3-4 feet.

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