Keep them like you show them here: ((((((())))))
You want them to be stored such that they are attracted to each other and either touching or have an easily magnetizable path (soft iron) between the attracting poles. That's the purpose of the magnetic keeper, to provide a magnetic path, or magnetic circuit, between the poles that are attracted to one another. Storing magnets in isolation is the next best case, and the absolute worst case is to store magnets in a repelling orientation.
I store my extra TJet magnets exactly as shown above and found that those old PC expansion slot blanking plates are the perfect size to sit them on to further enhance the magnetic circuit. It's all about closing as many of the magnetic circuits as possible.
Since we're doing lo-fi graphics ... here's the simplified model of the theory behind this. It's all related to "free poles" and I'm not talking the Lech Wałęsa type. You can conceptualize any magnetizable material as being made up of a series of tiny particles with north (N) and south (S) poles. When these poles are all oriented along magnetic lines you have a magnet. When they are not oriented or are random you do not have a magnet. When you have magnetizable material that can be permanently locked into a magnetic orientation you have a permanent magnet. How "permanent" this is depends on a number of things, and one of those things is "free poles."
Let's look at a pair of TJet magnets:
Magnet 1: (NS-NS-NS-NS-NS-NS(
Magnet 2: )NS-NS-NS-NS-NS-NS)
In your slot car motor the magnets are aligned like this with the parentheses being the magnet faces and backs:
(NS-NS-NS-NS-NS-NS( <armature> )NS-NS-NS-NS-NS-NS)
The NS pairs are the tiny magnetic particles inside the thickness of the magnet. Notice that inside the magnet every polarity pole has a mate of the opposite polarity right next to it, but on the face and back of the magnet there is either a N or a S pole by itself. These unmated poles are the free poles. The polarity of the free poles determines the polarity at the face of the magnet.
So what does this mean to magnet storage? Basically, if you look inside the magnet the internal particles all have an opposite polarity pole on both sides of them. This keeps them pretty much locked into that orientation. They have little reason to want to change their orientation. The free poles on the other hand are only locked in on one side. They can be swayed to change their orientation. One way to keep them from changing is to produce a mate for them. By placing an easily magnetizable material or "keeper" between them, a material whose internal particles can be magnetically aligned by the adjacent permanent magnet, the free poles now have mates on both sides and are now "locked in" to their magnetic orientation.
______Magnet 1__________Keeper_________Magnet 2_______
(NS-NS-NS-NS-NS-NS( [NS-NS-NS-NS] )NS-NS-NS-NS-NS-NS)
So that's the theory behind magnetic keepers. As shown above you'll still have free poles on the backs of the magnets, which is why placing them both on a magnetizable plate helps even more because it creates other paths and eliminates more free poles. If you have several sets of magnets then nesting them together helps as well as long as it does not create any mechanical stress due to the shape of the magnet that can break the magnet. If you try to nest a TJet magnet with a very strong neo magnet it may very well snap the TJet magnet in half. I learned the hard way.
I store my traction magnets stacked in a magnetically attracting orientation on big neo magnets. This seems to keep them at or near their peak but I have no illusions of this substituting for a good zapping. Be careful though, I have seen ceramics nearly demagnetized by monster neos. Never try to force magnets together in a repulsive orientation, never.
I hope this makes sense.
Last edited by AfxToo; 09-12-2010 at 01:15 PM.