This helps avoid confusion during the building process. To cut the groove in one edge of each piece, chuck a 3/16" straight bit in your router table, and lay out the stopping point for each groove, as shown in the corner detail drawing on page 21. Stopping the groove short of the top leaves a little meat above the rail tenon when the trunk is assembled, resulting in a stronger load-bearing joint for lifting the completed project. (Note: Use a 3/16" bit since ¼" plywood usually isn’t a full ¼" thick. With this bit, first make a pass to form the mortise, and then take a second pass to shave the mortise about 1/32" wider. Once you get a snug fit for the plywood, cut the rail tenons to fit the mortises.)
Now, use a piece of scrap wood that’s the same thickness as your corner pieces to test your router table setup. You want to be sure that the bit is exactly centered when you rout the ⅜"-deep grooves. Don’t miter the other edge of the corners until after the panels are fully assembled.
Forming the Rails
With the corner grooves completed, you can build the rest of the framework for the trunk. Following the dimensions provided in the Material List, cut your stock to size for all the rails (pieces 2 through 9), and label each piece with its position in the assembly. Take the rails over to your router table to cut the mortises in all the appropriate edges—that is, wherever a panel will be inserted (see the side and front panel assembly drawings, above).
After routing grooves in the rails, step back to your table saw to cut material for the lid front, back, sides, and supports (pieces 10 through 12). The sides and supports feature curved top edges, but for now, just cut the material to the overall dimensions provided in the Material List.
All the rails for the box portion of the project join the corner pieces with tenons. In addition, the lid supports join the lid front and back with short tenons. To cut these tenons, set up a ⅜" dado blade in your table saw, and clamp a protective wood face to the saw’s fence. Raise the blade a hair over ¼", and adjust the fence so it grazes the blade. Now, use your miter gauge to pass a test piece over the blade, and then test the tenon’s fit with the grooves in the corner pieces. Once the tenon on your test piece fits well, cut the tenons for the rest of the rails and supports.
Don’t forget that the tenons on the upper rails (pieces 2 and 3) need a ½" shoulder at their tops so they’ll sit flush with the corners (see the side and front panel assembly drawings).
Cutting the