I opened up my hard drive and pulled out (among other things) the top and bottom braces for the reading arm.
Each bracket contains a really powerful neodymium affixed to its underside.
When the two undersides come within a few inches of eachother, they accelerate toward each other and are seemingly unstoppable.
However, when they are placed close together but back to back (i.e. the magnets on the underside do not face eachother) there is no attraction whatsoever!
Somehow the material the bracket is made of is completely shutting down the magnetic field. This is strange because I tried placing both magnets on different sides of metal boards, wood, plastic etc and they are always attracted. But back to back, even up close, there is no attraction.
How does this work? Why is this happening?