I think that requires us to look at what we were doing in the shop 50 years ago. Men were machining parts one at a time on Cincinnati Mills with plain milling cutters spaced on an arbor with an outboard support. If your workpiece was CI, You might get 150 SFM and .015 chipload if you were lucky. Every time the tool got dull, one would have to setup all over with a regrind. Parts were shuttled down the line on tables from one press/machine to another where men stood and did one op at a time. If you were lucky enough to have a machine like a Natco, you could drill and tap more than one hole at a time. Otherwise, you were swinging a Carlton from one hole to another playing the "drift" as you locked up the column. Machinists were skilled men who turned cranks on machines that they knew better than their own wives! They made all their own setups and ground their own tools. They were craftsmen, but the work was painfully slow.
The transfer machine brought about a revolution in production. For instance, a workpiece could be transfered down a line through tunnel broaches, gun drills, line boring tools, milling cutters, and multi-spindled drills. Indexable carbide tools, quick-change tools and other tooling innovations made it possible to increase production dramatically.
The NC machine made it possible to do things that the old-timers could only dream of. They were tricky at first. Humidity and thunderstorms played the devil with the controls. Paper tape and Remex readers were real high-tech in those days! Coated carbides, Ceramics, Composites, and PolyC Diamonds made speeds and feeds unthought of before. 390 Aluminum used to almost grind off boring tools. Diamonds could now bore 100s of thousands of pin-bores with almost no wear. High-Helical ground Ti coated drills made spotdrills unnecessary on most ops., and lasted much longer.
Then came the CNC, CAD, and CAM. The first Computer Vision hardware filled a whole room. Now the same stuff fits in a shoe box. AutoCad, MasterCam and all the CNC equipment has come of age.
As you can probably tell, I am an old fart who made the transition from cranks to buttons. I would have to say that the combination of tooling and CNC have made the biggest mark on machining. I do look however in fondness at the old men in their demin aprons, smoking a pipe and fussing over a Jigmill. My own Pop was such a guy.  |