1. Start by drawing the position of the grooves to accept the side panels on the edge of the stock. As the two internal faces are to be grooved, you will want to position them away from the centreline. The X-shape illustrates the position of the groove in the stock.
2. Use this measurement to make a mark for a stop or clamp to limit the amount of travel of the router when machining the grooves. If your material allows it, machine the components in pairs.
3. I used a 12mm-radius cutter to match the thickness of the side panel. Using a square, capture the measurement from the tip of the cutter to the outside edge of the router base.

Wood Work Craft Woodworking Craft

