The pattern is used to make sure we have three equally spaced dovetail slots on the pedestal base and that the base lies flat on the router table when cutting the dovetails.
Before making the pattern we need to know the outer most diameter of the pedestal leg. This diameter will determine the size of the triangular fixture.
Once the largest diameter of the pedestal leg has been determined, draw a circle on the 1/4" plywood pattern material. We now have to draw an equalateral triangle around this circle. Draw a line on the edge of the circle, this will be the base line of the triangle. Draw a perpendicular line through the center of the circle.
Using a 60 degree plastic template along the base line, connect the base line and the perpendicular line where it intersects the circle. Repeat on the opposite side to complete the equalateral triangle.
Now draw a line through the center of the circle 90 degrees to each base line. Our circle is now divided into six equal parts. The marks on the circle will determine where we cut our jig and also be used later for locating the fence.