Principles
There are several different types of top. What they all share in common is the ability to stand upright while spinning. This gyroscopic stability requires that the top be symmetrical and that the pivot point create as little friction as possible.
The string-powered wooden models that were popular in the 1950s are now difficult to find. Unless you have a lathe or are a master-carver, they are also difficult to fabricate.
The finger-powered top consists of a circular disk with a section of dowel rod for the pivot is easy and quick to build.
How to Build It (The Easy Way)
If you have an old compact disc (CD) lying around, use a fine-tooth saw to cut a four-inch section of 5/8-inch dowel rod. Shape one end to a blunt point. Stick the point of the dowel rod into the hole in the CD and slide it up about three-quarters of an inch. It should be a tight fit and may require some sanding to get the CD in position.
Give the top a test spin. If it wobbles, make sure the CD is perpendicular to the dowel and that the point on your dowel is centered.
Once you have it properly adjusted, use epoxy to glue it in place.
How to Build It (The Less Easy Way)
If you don̵7;t have a CD that you wouldn̵7;t mind losing, an excellently balanced disk can be made with a hole-saw and your power drill. A hole-saw is a drill attachment that makes circular holes in wood. It is most often used for drilling holes for doorknobs in new doors. The coincidental result is that the circular wood plug that comes out of that hole has a one-quarter inch hole in the exact center. This makes what would otherwise be waste wood into a great disk for making a top.
Use your hole-saw to make a hole in a half-inch piece of plywood. Cut a four-inch piece of quarter-inch dowel rod. Use a pencil sharpener to make a blunt point on one end of the dowel.
Push the pointed end of the dowel through the hole in the center of the wooden disk until one-half of an inch sticks through the bottom of the disk. Use wood glue to secure the disk in place.
Spin and have fun.