Router Circle-Cutting Jig
My router didn't come with a circle-cutting jig, so I decided to make my own out of a few pieces of hardware. I started by making a pivot block from a small piece of wood. A short length of ¼″-dia. dowel is glued into a hole in the bottom of the block to serve as a pivot point.
Another hole drilled through the block allows it to slip over a length of 3/8″-dia. threaded rod. A couple of nuts and washers secure the block to the threaded rod (see detail). The end of the rod fits into a hole in the base of the router and is held in place with a machine screw.
To use the jig, first mark out the center of the circle you want to cut and drill a shallow, ¼″-dia. hole for the pivot pin of the jig. Then slide the block along the threaded rod to match the radius of the circle and lock it in place with the nuts and washers.
To rout the circle, first drill a starter hole at the edge. Then lower the router bit into the hole and rout the circle in multiple passes, lowering the bit ¼″ between each pass.
Have a nice weekend,
Online Editor, ShopNotes