The first year of high school I had to take machine shop for three months. The instructor divided us into three groups. The first group started on the lathe. the second on the grinder and the third started with the file. At the time being a 14 year old kid did not seem very glamorous to have to take a 1/2" by 2" by 3" block and get all six sides square and to the proper measurements. From there went to drill press, grinder, and that glamorous lathe. I was one of the few guys that able to get that far( some lathe guys never did finish their project). Years later, I figured out that learning to file was one of the most valuable lessons in machine work. I also fine it satisfying and relaxing.
