Anyone interested in the topic should check out the Gingery series on building your own workshop from scrap, which is all based on aluminium casting
"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.