In one of the earlier posts, I mentioned my perennial side hobby: CNC machining. In theory, it’s a straightforward and hassle-free way to make just about anything in the privacy of your home. In reality, it’s a portal to the demon-infested dimension of mechanical engineering and materials science. As with 3D printing, until you win that battle, you won’t have much luck making functional and durable parts.One of the many rabbit holes I got pulled into over the years is the design of involute gear...