I thought and thought and thought and thought…
So, I came up with this potential simple definition of machine tools. Ready?
Anything that is designed to work automatically (without direct human control). The word “designed” is the trick here. If I go to Harbor Freight and buy a lathe, it is obviously a lathe, which is a machine that is designed to be automatic. Easy, right? If I instead go to Harbor Freight and buy a large electric hand-held drill, then I build a bracket to hold it into a position and a framework for tooling and then use it as a lathe, what have I done? I’ve designed a lathe (and subsequently built it). What if I build a lathe from scrap-wood out of my burn pile? It’s still designed to be a lathe, so it is a machine! Get it? What if I fasten some pieces of angle iron to my table saw so that it can be used as a lathe? Well, if it is designed in such a way that anyone who knows how to use a lathe can easily use this thing as a lathe, then it is obviously a lathe, even if a bit unconventional. The design which makes things automatic is the measure by which you could say that it is a “machine”.
What wouldn’t be a lathe? Using a table saw with only the push bar and a steady hand to make something that looks like it was cut on a lathe wouldn’t make it a lathe. So the separation then is not the creativity of the person using the tool, but the intent and purpose of the design of the tool. And that would include the design from the factory, as well as the design of any modifications that are made to the tool. That, to me seems fair. It can be objectively measured, so that everyone can know and understand what is expected, and nobody has an advantage or disadvantage.
What do you think? Is the word “automatic” sufficient to separate machine tools from other tools? Is the word “designed” sufficient to describe the difference? Just trying to help. Obviously, it is ultimately up to the judges.