I made these originally with a lot of little pieces glued together. It just dawned on me that I could rout the slots, but I'm not sure how to make the template to follow. My thought was to use a 3/8" plunge bit. I wish I had a CNC or even a 3D printer. Each slot is 6 3/4" long x 3/4" deep x 3/8" wide. I can build the outer portions of the box and lid around the main slots box.