I like to use an edge guide to rout grooves and dadoes. However, most guides don’t have enough reach to rout more than a few inches from the edge. So, I built my own guide to take care of the problem. Now, I can easily rout straight grooves and dadoes, no matter where they are on the workpiece.
The drawing shows how simple this guide is. The long arm is constructed out of 3⁄8" plywood, and its width matches the router’s base. The arm attaches to a stout fence that will keep it steady during use. All of this combines to provide a lot of stability to the guide.
A jig this size can be a challenge to keep square to the workpiece, so I added a couple of things to help. This drawing shows how the arm fits snugly between two runners in the fence. Plus, a rectangular guide block fits into the slot to help the guide stay square. The router is mounted to one end of the arm (remove the router’s baseplate first). The arm attaches to the fence with a carriage bolt, washer, and threaded knob through the guide block in the center slot.
