Here are several free files, if you have a laser. From time to time I will update this list with new files.
I created this tool for my design projects, so I could test out the wood to see what notch fit the best on each of my designs. Because wood varies in thickness and the caliper is great to use but I can just take the corner of my wood and find the right size for that piece, and know it will fit. I include this file with every design I create that requires a notch.