The origin of mechanical precision is a classic chicken-and-egg problem: If you need a precision machine tool to make a precision machine tool, where do precision machine tools come from, in the first place? There’s the historical question—how did human beings go from sticks and stones to diamond-turning optical lathes capable of millionth-inch precision? And there’s the slightly humbler, more practical version of the same problem—if I don’t have access to a precision machine tool, for whatever reasons, how do I go about making one?
Like maker patron saint Dave Gingery, septuagenerian Palestine, Texas, resident Pat Delany has a passion for that practical problem. Inspired by a WWI-era improvement in the expedient manufacture of machine tools by Lucien Ingraham Yeomans, Pat has been working since 2002 to develop a metalworking lathe design that uses concrete parts cast in wooden molds to achieve high precision at a rock-bottom price. Like $100-$200. Generally, the method involves casting the bed with slightly oversize voids to mount the ways and other parts requiring precision alignment. The parts are then carefully aligned using screws or shims, and fixed in place by pouring low-melting type metal into the extra space.
Pat’s current design lives on Make: Projects, and you can check it out at the link below. [Thanks, Pat!]