One day, a long time ago, I walked into a small machine shop after hours and asked the owner what the words "Screw Machine" in the business' name meant. There w

One day, a long time ago, I walked into a small machine shop after hours and asked the owner what the words "Screw Machine" in the business' name meant. There were lots of small shops around called "x Screw Machine Co." and I was curious. He took me on a short tour of his shop and showed me what a screw machine was. Most of the equipment was 40+ years old and many of them still had the stencil, "Property of War Department." In short, it's a bar-fed high-speed automatic lathe with all the automation done with cams and gears. I watched it make some kind of specialized spacer, each piece taking about 40 seconds, and as a software engineer familiar with CNC, I was amazed that this could be done so fast without a single computer in sight. And yes, there are now CNC versions that can do even more mind-blowingly complex operations, but I'm still impressed by cams and gears.