Steve had posted something about moldable, tuneable magnets
at;
http://www.escribe.com/science/keelynet/m8024.html
As you can see in Johnson's 'Stonehenge' model, he simply
connects rectangular magnets to build the U shape in that
particular design. The patent shows crescent shaped rocker
magnets.
This subject has come up before....I had read a few years
ago where it was recommended to mix iron filings or powder
in a resin that had the desired shape, the combined strength
of the filings would function almost like a full magnet,
though I think you'd have to polarize them before the resin
set, so they were all facing with the same poles in a
preferred direction.
-----------------------
NASA has such a process;
http://www.nctn.hq.nasa.gov/innovation/Innovation54/show54.htm
-----------------------
AZ Industries offers formed magnets to your specs but I'll
bet they are expensive;
http://www.futuremag.net/magnete.htm
-----------------------
http://www.eskimo.com/~billb/neodemo.html
http://www.keelynet.com/interact/archive/00000974.htm
Hans von Lieven wrote:
>
> .........Can anyone point me in the right direction on where to get info on how to
> make magnets?
> I'm really looking for a way to build a Johnson PMM and see if/how well it
> works. But it requires some uniquely shaped magnets which your just not
> gona find off the shelf. 8)
>
> -Jerry (jasegler@mtco.com)
>
> I suppose you want to do this on the cheap jerry. Well there are some ways to do this, though they will not be as
> powerful as the ones specially made.
>
> The oldest way is to take a bar of soft iron and stroke it in one direction over and over with one of the poles of a
> strong magnet. This creates a fairly good magnet. You then bend the iron bar in the required shape. Do NOT use
> heat to shape the newly made magnet as the heat will destroy the magnetic field. Any additional shaping can be
> done by filing, taking care not to warm up the metal.
>
> The other way is to use a standard magnet and extend the poles with a specially shaped piece of a ferromagnetic
> material of some sort. You could even use iron filings held together with some resin or ground up ferrite
> reconstituted with some sort of thin glue etc. The magnetic field will extend through the added material giving you
> the required field characteristics.
>
> Hope to have been of some help
> Hans von Lieven
>
> -------------------------------------------------------------
> To leave this list, email <listserver@keelynet.com>
> with the body text: leave Interact
> list archives and on line subscription forms are at
> http://keelynet.com/interact/
> -------------------------------------------------------------
-- KeelyNet - From an Art to a Science Jerry W. Decker - http://www.keelynet.com/discussion archives http://www.escribe.com/science/keelynet/KeelyNet - PO BOX 870716 - Mesquite, TX 75187 - 214.324.8741------------------------------------------------------------- To leave this list, email <listserver@keelynet.com> with the body text: leave Interact list archives and on line subscription forms are at http://keelynet.com/interact/ -------------------------------------------------------------