Measure and cut two circular pieces of plywood using a scroll saw. Make one 2 feet in diameter and the other 3 feet.
Remove the middles of the circular wood pieces using the router saw without cutting through the edges. Prop each circle on the saw horses and remove a circle from the middle of each piece large enough to leave a hollow circle with edges measuring 3-inches wide.
Cut lengths of dowel to serve as support structures for the base. Make six 20-inch lengths using the scroll saw.
Attach the dowels to the smaller wood circle. Use glue to fasten the dowels to the outside of the circle, spacing them out evenly around the circle. Line up the ends of the dowels with the bottom of the wood circle. Reinforce the joints with screws, driving them in through the dowels from the outside, into the plywood.
Place the larger wood circle inside the cylinder formed by the dowels. Attach it in place at the ends of the dowels as you attached the first circle inside them at the other end.
Smooth and shape the frame using the disc sander. If you want to make it look more like a store-bought base, round down the corners of the wood circles.
Stain and varnish the wood, if desired.