This article is from the Radio Control (R/C) Flying FAQ, by Shamim Mohamed email@example.com with numerous contributions by others.
Rare-earth magnets, of which the most common type is samarium cobalt, are
stronger for a given weight and volume than ferrite magnets. Perhaps an
even more important reason for getting a cobalt motor is that they also
have better brushes, bigger shafts, better bearings, are built more
carefully, and so on. For the serious electric flier, they are worth the