TWO general divisions of precision cylindrical grinding are described and illustrated in this paper-the centertype and the centerless.
Accurate centertype grinding depends principally on four basic general principles: construction of the machine and required fixtures; grain and grade of grinding wheel; correct work speed; and the human element.
A rigid machine is necessary to eliminate vibration. Grain and grade of the grinding wheel depend upon the size of material and work being ground, amount of stock removed, and the required finish. Correct work speed is essential to maximum grinding-wheel life, desired stock removal, and required finish. Procedure for proper centering of work is outlined.
By means of specific examples described in detail, varied applications of cylindrical grinding to automotive parts, as well as to billiard balls and fountain pens, are presented. These examples describe equipment for multiple-wheel, eccentric, and contour grinding, and show applications of in-feed and through-feed methods.
Advantages of centerless grinding over centertype as applied to work of a varying nature are set forth. Causes of trouble, such as chatter, scratches on work, and work ground hollow in the center, are described with their remedies.