Here is some additional information about the 8 foot windmills.
The wheel on the 8 foot model is 22 inches in diameter.
The windmill is 8 feet high from the ground to the top of the wheel.
At the top of the tower is a mast head. There is a pivot which is a 1/2 inch steel bent 90 degrees. One end goes into the mast head the other end is where the wheel is mounted. The tail attaches to the pivot.
The wheel is hand balanced at the factory. It has ball bearings on the front and back of the wheel. There is a grease zerk on the wheel so the bearings can be greased.
It is 30 inches from the center of the pivot to the trailing edge of the tail. It is 7 inches from the center of the pivot point to the end on the shaft where the wheel attaches. The windmill will need to be located at least 32 inches from obstacles such as trees, buildings and so on. This is measured from the center of the tower.