434 



APPLIED SCIENCE 



fastening to the bed the casting or metal, held in a chuck 

 or on centers. The variety of operations which the milling 

 machine can perform is almost limitless. The work is fed 

 against a cutter whose teeth are so cut that it works on the 

 principle of a coarse file. Spur gears, bevel gears, and spiral 

 gears may be cut, taps and reamers fluted, and many other 

 things performed which could be done on other rfiiachines 



only with difficulty, 

 unless the machine 

 were specially built. 

 To run the milling 

 machine to its best 

 advantage a knowl- 

 edge of trigonome- 

 try is required. 

 Charts are furnished 

 covering the most 

 common require- 

 ments, but to cover 

 everything the ma- 

 chine can do would 

 require an unreason- 

 able number of 

 charts. 



There are three classes of milling machines: (1) the plane 

 milling, (2) the universal milling, and (3) the special milling 

 machine. The operation of successful milling requires much ' 

 study of milling cutters. These cutting tools turn on the 

 arbor (principal support) of the machine, while the table 

 feeds the work horizontally, vertically, or crosswise. The 

 action of the machine is as follows : The power is transmitted 

 from the pulley on the countershaft to that on the spindle, 



FIG. 199 Universal Milling Machine. 



