"The project that I am gradually preparing for is to build the Gingery Lathe. The late Dave Gingery wrote a seven-part series of books in which he describes how to build a foundry, lathe, shaper, drill press and other metalworking tools from scrap at a tiny fraction of the cost of buying each. For me it’s not so much the cost savings (or the post-apocalypse skills!) as it is the opportunity to learn for myself how tools work at a fundamental level."
I have watched many chapters of the Gingery lathe casting series, because I have always loved process and tooling and youtube is now FULL of amazing documentary footage. I found it strangely enjoyable to watch.
Many parts of machine tools like lathes need to be as flat as possible, because if the surface of the tool is not flat then that error is transferred to the object you are tooling. To get, say, a lathe bed flat, you buy or make a reference flat surface, paint the lathe bed blue, and then rub the surfaces together. The parts where the blue rubs off are the high parts. You take a scraper -- basically a modified chisel that takes off a thin layer of metal -- and scrape down the high parts. Wipe off the paint, repeat until there are no more high spots. It is very tedious.
"The project that I am gradually preparing for is to build the Gingery Lathe. The late Dave Gingery wrote a seven-part series of books in which he describes how to build a foundry, lathe, shaper, drill press and other metalworking tools from scrap at a tiny fraction of the cost of buying each. For me it’s not so much the cost savings (or the post-apocalypse skills!) as it is the opportunity to learn for myself how tools work at a fundamental level."
From the comments.