Creating Large Permanent Magnets

[Danny B.]

For the science fair project my partner and I intend to pursue this year we need several extremely long strips of permanent magnets of decent strength. However, days of online database searching has revealed little more than the general materials that would be needed and places to buy small rare earth metal magnets. I was hoping that one of you may be able to help answer a couple of my questions, or at least point me in the right direction.

- Where can I find quality magnetic literature?
- With whom could I converse that is highly knowledgeable about magnets?
- How would I go about the creation of large Permanent Magnets?
- And any other information/sources/comments that you may have.

Again, the creation of the magnets is not the point of the project, but will serve as a base for the project as it evolves into something much more complex.

Any and all help is appreciated [:

[deleted-71588]

How would I go about the creation of large Permanent Magnets?

Manufacturing permanent magnets is a little bit of science and a lot of art that has to do with mastering trade offs to produce something with the appropriate mix of properties. What dimension do you need to be large? What orientation do you need the magnetic field in with respect to the magnetic material? For example, if you take two permanent bar magnets that are 2 inches long and have something like 1/4 inch x 1/2 inch faces and you put the North pole of one against the South pole of the other so it makes a four inch long magnet, the external magnetic field is spread out into more volume so the relative field strength doesn't increase much and may actually decrease. If you try to put the two north ends and the two south ends togeter, they repel each other. If you think about magnetizing a 1/2 inch square x 4 inch long magnet from a single piece of stock, the same forces that repelled the two like ends will actually occur to some degree and prevent the manufacturer strong magnets. If the manufacture of the magnets is not the primary investigational area of your project, why do you want/need to go to the trouble of manufacturering the magnets you need. Doing a great science fair project in a reasonable amount of time means you have to focus on where you spend your tim so I'd suggest this would be an area of make vs buy that needs to go to the "bye" cataegory.

[Danny B.]

What dimension do you need to be large?

Theoretically? Enough to grid a city's streets.
Literally? Roughly five foot strips with a height and width of an inch or so. Although, this is just a rough estimate. I have yet to do any kind of measuring on what kind of force magnets of varying sizes can have, or an equation that would help me calculate it.

... and you put the North pole of one against the South pole of the other... the external magnetic field is spread out into more volume...

To clarify, the volume of the magnetic field increases, but the strength it has is more than likely weakened?

If the manufacture of the magnets is not the primary investigational area of your project, why do you want/need to go to the trouble of manufacturing the magnets you need.

Too add width to our project. While it is unlikely that knowing how the magnets are manufactured (unless we are forced to make them) will play a big part in our project's success, it could potentially provide a future place of improvement or help to answer a judge's question. At the very least, it aids in the understanding of our project's lesser parts and helps to cover all of our bases.

Doing a great science fair project in a reasonable amount of time means you have to focus on where you spend your time...

I completely agree! My partner and I have branched off into separate research avenues. He is currently finding information that's absolutely necessary to our project's core while I branch off on related tangents. We intend to compare results next week, converse, switch roles, and then evaluate our position at the end of that two week time line.

[deleted-71417]

Hi,

You asked in your original post where you could find people knowledgable in Magnetism. One place is the IEEE Magnetics Society. They have local chapters around the country who might be useful to you. Here is a link to their website:

http://www.ieeemagnetics.org/

It may be useful to check out the Links of Interest link on the bottom left of the website - it leads to names of experts, webpages of interest, and other goodies.

This is a fascinating field - have fun exploring it!

Barrett L. Tomlinson

[deleted-71588]

Theoretically? Enough to grid a city's streets.
Literally? Roughly five foot strips with a height and width of an inch or so. Although, this is just a rough estimate. I have yet to do any kind of measuring on what kind of force magnets of varying sizes can have, or an equation that would help me calculate it.

You need to rethink this aspect. I doubt you really need large magnets for things of that scale. Think about it, the earth itself is one huge magnet, no one point it its magnetic field is very strong, but its field is huge. I suspect what you really want is a large number of smaller magnets arranged so you get a magnetic field appropriate for whatever you are really trying to do with it.

[deleted-71447]

Hi Danny B,
I just wanted to add to excellent advice already given - it would be very helpful if you would describe the basics of your project. For example, what is the scientific question or engineering challenge that you are trying to address?
We can certainly provide technical advice about magnets, but I think you will find many more benefits to your project if the experts are able to understand and advise you with regards to your overall plans.
Thanks,
Chris

[Danny B.]

One place is the IEEE Magnetics Society. They have local chapters around the country who might be useful to you. Here is a link to their website:

Thank You! If this is the topic that we decide to do our project on, and we currently intend to, than this site could prove very valuable [:

I suspect what you really want is a large number of smaller magnets arranged so you get a magnetic field appropriate for whatever you are really trying to do with it.

You are more than likely right. The specifications I provided are based on my limited experience and knowledge of magnets and their properties.

it would be very helpful if you would describe the basics of your project.

To begin with, I'm not entirely sure that this idea is even plausible, but here is what we are attempting to accomplish. A new method of transportation, heavily reliant on magnets, that results in high energy efficiency.

Originally, we were thinking that a flat magnetic field would need to be created over a city's streets, and that strong magnets in the shape of a square or rectangle could be fitted to new vehicles and pivoted to direct propulsion; other ideas running off on similar tangents.

Sorry for not being more specific to begin with.


** Edit **

Such as combining the MagneTruck idea with that of MagLevs to create a frictionless propulsion system (small amounts of electrical energy most likely being necessary.)

[deleted-71447]

I'm not entirely sure that this idea is even plausible, but here is what we are attempting to accomplish. A new method of transportation, heavily reliant on magnets, that results in high energy efficiency.

OK, thanks for the information. It might not be feasible to develop a truly "new" method of transportation for a science fair project, but there is certainly no harm in starting out with that goal in mind, researching the topic, and seeing where it leads you.
Students have asked previously in these forums about maglev. If you enter "maglev" into the search box at the top right of the forum you'll find these topics as well as the links and advice that were provided previously.
http://www.sciencebuddies.com/science-f ... search.php

Good luck!
Chris