Lathe Operation

The art of operating a lathe without a computer to control is is quickly becoming a lost art. The engine lathe (so called to distinguish it from the foot lathe (pedal powered) was sort of the PC to the machine age. Machinery percolated along beginning in the mid 1800's in ernest with the development of the Twist drill, and progressively better understanding of metallurgy. Mechanization bloomed at the dawn of the 20th century with the development of the automobile, and the perfection of High Speed Steel (HSS). Everyone fought for a place in the machinery business, and the lathe was the key piece of machinery, used to make more machinery.

Machine tools were recognized as key items in World War II and the War Production board strictly limited the availability of machines to the war effort and huge numbers of machinists were recruited and trained to run them and lathes got bigger and faster, though the last real breakthrough in productivity was in the development of carbide cutters which occurred in the 1920's.

One of the unique features of the engine lathe is, however, that the basic design has remained unchanged for a 150 years. By 1900 or so, the design became fairly stable and uniquely, any lathe made in the 20th century, if in good condition, is likely to be able to produce results which are perfectly good. To be sure some features have been added in the last century that improve productivity, but for the most part they don't cause the lathe to produce better widgets, just more of them.

Cone head Lathe
Note the Cone and flat belt
Gear Head Lathe
Gear Head Lathe--enclosed gearbox with oil lubrication and roller bearings.

Prior to the development of 'quick change' around 1905, for example, one had to sit down with a pile of gears and change them around on the gear train that fed the threading screw in order to obtain different thread pitches. Quick change, introduced a shift lever to shift from one gear to another by sliding a lever, making a half an hour gear shuffle into moving a gear shift lever. Similarly in the 19th century, electric motors were not common and lathes were usually powered by an overhead rotating shaft called a line shaft, with a flat belt dropping down to the lathe. Since lathes need to turn at a variety of speeds, a multi-stepped pulley was provided which allowed the operator to select several different speeds by changing belt pulleys. Lathes designed to receive power from overhead line shafts on a multi stepped pulley are called "cone heads" because the dominate visible feature is the cone pulley. The improvement over the century was to replace the overhead belt drive with an electric motor and a big gear box.

These added convenience, but you still engage your work at a single point with either HSS or carbide just as you have since the 1920's (or about 1900 in the case of HSS). What's new are theh digitally controlled machines that take a lump of iron and make something useful out of it based on a computer programmed input. Great for production work, but don't do much for you if you are trying to invent a repair to an old broken piece of machinery.

Unfortunately folks who learned to run lathes in WWII are getting up there. After all the war ended about 65 years ago, and the machine tools they used are going to the scrap yard at alarming rates. If I do anything useful on this website it will be to record a few ideas on how to use the classics.

- - Updated 12/29/2012
- - Updated 12/31/2009