CNC verses Manual Machines

I remember one of my first jobs I did on a manual engine lathe. The part was called a test bar. The rough stock was cast iron. Basically all it was is a part that was 8 inches in length and had threads on either end. To the best of my recollection the thread size was 1 inch 8 threads per inch. In the middle of the part the diameter was around 3/4 of an inch. This diameter had to be polished and free of toolmarks. All they really did with this part was to screw it into some type of part to test the strength of it. When the test bar broke they would record how much pressure it took to break that bar. Anyhow back to the point I'm trying to make,the test bar itself took nearly 2 1/2 hours to make from rough stock to finish. It also had some fancy radius designed on it. To achieve making that radius on the part you had to take a tool and hand grind the tool to the shape you wanted to achieve. You could spend an hour just making the tool itself to achieve what they were asking for on the blueprint. In today's world the CNC machines, by the way CNC stands for Computer Numerical Control,could take that same part that took 2 1/2 hours to make manually and virtually produce a more accurate part in 5 minutes. CNC technology has advanced the world of machining tremendously. In the next post I will share some insight on some of the history of the CNC machines that I have witnessed throughout my career in machining.