A traditional weathervane comes in two sections. The lower-half of a traditional weathervane is fixed and this is the section where the four points of the compass are aligned to their correct most accurate positions. The upper section of a traditional weathervane is the part of the vane that rotates and indicates the exact wind direction. The upper section can be any ornament as you wish, and the decorations often reflect the building the weathervane is atop.
A weathervane ornament not only can display an animal or a gesture, but it can reveal a lot about you as an individual. A weathercock is also a weathervane, it just has a replication of a rooster as its decorations. The only rule with the upper section of a weathervane, is that the greatest amount of mass is to be on one side of the spindle, in other words, the weathervane has to have unequal weights on either side of the spindle. The inequality of the weathervanes weight, causes resistance for the oncoming wind, therefore forces the section with greater mass to the back and forces the pointer (the lighter end) to face the wind. For example, if the weathervane is pointing towards ‘N’, it means that the wind is indeed coming from the northern direction.
Most people wonder if it is possible to hand make a weathervane themselves. There are only two basic rules that must be followed when designing your own weather vane. Number one is that the ornament must have “equal area” on either side of the center. And the other rule is that the ornament must have “unequal mass” on either side of the center. So yes it is possible to create your own weathervane but all in all, it may be extremely hard work.