CNC | History of Machine Tools

The development of metal cutting machines (once briefly called machine tools) started from the invention of the cylinder, which was changed to a roller guided by a journal bearing. The ancient Egyptians used these rollers for transporting the required stones from a quarry to the building site. The use of rollers initiated the introduction of the first wooden drilling machine, which dates back to 4000 BC.

In such a machine, a pointed fl int stone tip acted as a tool. The first deep hole drilling machine was built by Leonardo da Vinci (1452–1519). In 1840, the first engine lathe was introduced. Maudslay (1771–1831) added the lead screw, back gears, and the tool post to the previous design. Later, slide ways for the tailstock and automatic tool feeding systems were incorporated. Planers and shapers have evolved and were modified by Sellers (1824–1905). Fitch designed the first turret lathe in 1845. That machine carried eight cutting tools on a horizontally mounted turret for producing screws. A completely automatic turret lathe was invented by Spencer in 1896. He was also credited with the development of the multispindle automatic lathe. In 1818, Whitney built the first milling machine; the cylindrical grinding machine was built for the first time by Brown and Sharpe in 1874. The fi rst gear shaper was introduced by Fellows in 1896. In 1879, Pfauter invented the gear hobber, and the gear planers of Sunderland were developed in 1908. Figures 1.4 and 1.5 show the first wooden lathe and planer machine tools.

FIGURE 1.5 Wooden planer machine (1855).

Further developments for these conventional machines came via the introduction of copying techniques, cams, attachments, and automatic mechanisms that reduced manual labor and consequently raised product accuracy. Machine tool dynamometers are used with machine tools to measure, monitor, and control forces generated during machining operations. Such forces determine the method of holding the tool or WP and are closely related to product accuracy and surface integrity. In 1953, the introduction of numerical control (NC) technology opened doors to computer numerical control (CNC) and direct numerical control (DNC) machining centers that enhanced product accuracy and uniformity. Machine tools have undergone major technological changes through various developments in microelectronics. The availability of computers and microprocessors brought in flexibility that was not possible through conventional mechanisms.
The introduction of hard-to-machine materials has led to the use of nontraditional machining technology for production of complex shapes in superalloys. Nontraditional machining removes material using mechanical, chemical, or thermal machining effects. ECM removes material by electrolytic dissolution of the anodic WP. The first patent in ECM was filed by Gussef in 1929. However, the first significant development occurred in the 1950s. Currently, ECM machines are used in automobile, die, mold, and medical engineering industries. Metal erosion by spark discharges was first noted by Sir Joseph Priestly in 1768. In 1943, B. R. Lazerenko and N. I. Lazerenko introduced their first EDM machine, shown in Figure 1.6. EDM machine tools continued to develop through the use of novel power supplies together with computer control of process parameters that made EDM machines widespread in the manufacturing industries. The use of high-frequency sound waves in machining was noted in 1927 by Wood and Loomis. The first patent for USM appeared in 1945 by Balamuth. The benefits of USM were realized in the 1950s by the production of related machines. USM machines tackle a wide range of materials including glass, ceramic, and diamond. The earliest work on using electron beam machining (EBM) was attributed to Steigerwald, who designed the first prototype machine in 1947. Modern EBM machines are now available for drilling, perforation of sheets, and pattern generation associated with integrated circuit fabrication. Laser phenomenon was first predicted by Schawlaw and Townes. Drilling, cutting, scribing, and trimming of electronic components are typical applications of modern laser machine tools. The use of NC, CNC, computer-aided design or computer-aided manufacturing (CAD/CAM), and computer-integrated manufacturing (CIM) technologies provided robust solutions to many machining problems and made nontraditional machine tools widespread in industry.

FIGURE 1.6 First industrial EDM machine in the world. Presentation of the Eleroda D1 at the EMO exhibition
in Milan Italy, 1955. (Courtesy of Charmilles, 560 Bond St., Lincolnshire, IL.)