I am a beginner user with a router and need some advice for accessory purchase for a project. I searched some threads but did not find what I am looking for. I am making cutting boards and some will have a juice groove. What do I need to be able to follow a 3/4" plywood pattern as I plunge into the cutting board to make a groove in the board? It looks like I need a guide bushing adapter and copy ring but it is not real clear to me how it all works. Thanks in advance for and advice.