Grinding of Milling Cutters

Grinding of Milling Cutters Points : Grinding of Milling Cutters Tool and cutter grinding involves the grinding of milling cutters, drills, counter-bores, reamers, and many other kinds of cutting tools. This type of grinding normally is done on a tool and cutter grinder. The universal cutter grinder can grind cutters of various shapes by using special attachments and specially formed grinding wheels. Generally the flaring cup, plain or disk, and dish or saucer wheels are used on cutter grinders. The flaring cup wheel is used to grind clearance on teeth with wide lands, and to gum out slitting saws and the pacing between the teeth of milling cutters. The plain or disk wheel is used to grind the clearance on cutters with narrow lands on the teeth. The dish or saucer wheel is used to grind formed cutters. For general purpose cutter grinding, select a soft, free- cutting wheel and take very light cuts so that the temper is not drawn from the cutting edge. Generally speaking, wheels of grain size 30 to 60 and J or K bond are best adapter for high-speed cutters. The shape of the wheel depends on the shape of the cutter to be sharpened.
Plain milling cutters with straight teeth can be ground on plain or, universal grinder. Milling cutters are sharpened by using either the outer edge of a disk wheel or the face of a cup wheel. Form relieved cutters, Such as gear and radius cutters, are sharpened by grinding the face of each tooth with a saucer-shaped wheel. In actual practice, the grinding wheel revolves downward toward the cutting edge, so that the action of the wheel forces the tooth against the tooth rest. This results in a burr or wire edges being left on the tooth, which should be oils-stoned off.
A keener cutting edge, free from burr, is obtained if the cuter to be sharpened is reversed. The disadvantage is that it is more difficult to maintain the tooth rest in position because the rotation of the grinding wheel tends to carry the cutter sound.