October 12, 2022
Our Facebook page recently displayed some great vintage photos of the old Mesta Machine shop. Back when American firms built the biggest and best equipment in materials processing, Mesta was one of the go-to outfits. The Greater Pittsburgh Area — really Western Pennsylvania and Northeast Ohio — was jammed with mill builders and their key suppliers. If you were in anyway connected to metal processing you crossed paths with Mesta, Wean United, Herr Voss, and the other giants. Many of the mills those firms built are gone now, obsoleted by improved methods or changing trade policies. But lots of their equipment soldiers on with replacement parts made by the survivors of the de-industrialization that has been going on for forty years or more. Sadly, some of the unique capabilities of the original builders are gone forever and creative solutions have to be found to make some key parts. For example, no one can make bevel gears of the size and pitch once common in 1960. Sure, you can whittle replacement parts out on a milling machine, but most designers avoid having anything to do with a 50-module stub tooth. The ability of the equipment designers to create such incredible products in the pre-computer days is a testimony to their understanding of first principles. They knew their material properties too and were not afraid to throw lots of mass at a problem. No one pestered them with a finite element analysis showing them they could reduce a wall thickness by 50% and still have a machine that survived the warranty period. We all enjoy the pretty pictures that emerge from a modern 3-D modeling program, but those old pen-and-ink blueprints are artwork all by themselves. Having attempted a few inked drawings in my youth, I cannot imagine the pressure the draftsmen were under to keep up with the unnamed geniuses designing the machines that shaped our modern world without smudges, drips, or typos. There was no “save” button on a drafting board.