Build a circle jig that doubles as an edge guide.
Step 1: Measure
Measure up a length of 1/4 inch thick wood that will accommodate a router.
Step 2: Cut Edge Guide
Measure and cut a piece of wood to use as a guide.
Step 3: Cut
Cut the 1/4 inch thick wood to size.
Step 4: Measure and Mark
Cut a second piece of wood that is slightly shorter than the one that will attach to the router. Mark three lines equidistant down the length of the piece.
Step 5: Rout
Rout out the three lines on the top piece and a slightly wider section on the bottom piece.
Step 6: Mark Holes
Mark holes for the router base.
Step 7: Drill
Drill the holes.
Step 8: Glue
Glue the two pieces together.
Step 9: Set
Use a forstner bit to drill holes that will set the screw heads flush with the bottom of the piece.
Step 10: Sand
Sand the square end of the wood to a round shape.
Step 11: Oil
Use oil or varnish to protect the wood.
Step 12: Drill
Drill the edge guide to accommodate hardware.
Step 13: Assemble Edge Guide
To make the edge guide put the guide under the unit and fasten.
Step 14: Assemble Circle Jig
To make the circle jig put the guide on top of the unit and fasten. Then fasten a screw into the center of the radius to cut a circle.