Builder [bluesyann] made a functional box joint cutter from a stationary jigsaw, scrap wood, common hardware, and a 3D-printed jig. The key component is a custom wide blade built by epoxying three jigsaw blades together, two of them snapped into sections, producing a single extra-wide cutter that removes each notch in one pass.
The stationary jigsaw cuts the same notch every time. Consistent spacing comes from a 3D-printed jig: each finished notch indexes onto it, positioning the workpiece for the next cut. No table saw, no router table, no laser cutter. The full build is documented on Instructables and requires some trial and error to dial in, but the system is repeatable once calibrated.
The original is worth reading for the blade construction details and jig geometry, not just the concept. This is a case where the process is the story. If you want the automated version of this same problem, Hackaday covered a robotic table saw doing finger joints back in January 2018.
[READ ORIGINAL →]