Originally Posted by Andrew S
Is there a specific magnet you need to get? Or just the biggest one you can find?
Here is some FACTS about your rotors.
Neodymium (more precisely Neodymium-Iron-Boron) magnets are the strongest permanent magnets in the world.
What are neodymium magnets made from and how are they made?
Neodymium magnets are actually composed of neodymium, iron and boron (they are also referred to as NIB or NdFeB magnets). The powdered mixture is pressed under great pressure into molds. The material is then sintered (heated under a vacuum), cooled, and then ground or sliced into the desired shape. Coatings are then applied if required. Finally, the blank magnets are magnetized by exposing them to a very powerful magnetic field in excess of 30 KOe.
Can I make a magnet that I already have any stronger?
No, once a magnet is fully magnetized (saturated), it cannot be made any stronger. (New)
So, you can't make them stronger then they where new.
Does stacking magnets together make them stronger?
Yes, two or more magnets stacked together will behave exactly like a single magnet of the combined size.
This is what I use to recharge my rotors.
I combined 4 N42 Neo magnets (1''X3'') to form a block.
What does the "N rating", or grade, of the neodymium magnets mean?
The grade, or "N rating" of the magnet refers to the Maximum Energy Product of the material that the magnet is made from. It refers to the maximum strength that the material can be magnetized to. The grade of neodymium magnets is generally measured in units millions of Gauss Oersted (MGOe). A magnet of grade N42 has a Maximum Energy.
This info was cut a pasted from here: