This shop tip describes a method of gluing together pie shaped segments into a circle. Make the jig by cutting a circular hole from 3/4” plywood-its diameter should be about 1/8” to 3/16” larger than the diameter of the segmented circle you want to create. This piece is clamped to a 3/4” plywood base with waxed paper inserted between the two pieces of plywood to prevent the segments from sticking to plywood base. Instead of waxed paper, one can also use a piece of polyester or melamine-coated particle board. Assemble the glued-up segments within the circular cut-out. Then push or drive small wooded wedges between the pie segments and the inside wall of the circular hole. This pushes each segment towards the center and the close contact with the two segments next to it. Enough pressure should be applied with the wedges to form a good glue bond. After the glue has set the wedges are removed, freeing the segmented disc from the jig.
Not only can discs be glued-up in this manner, but this jig works equally well for making circular segmented rings or frames. In this case the segments are made only as long as you want the width of the ring or frame to be. It also works when gluing up staves.
-C.E. Rannefeld, Decatur, Alabama