for best results, the machine should be equipped with a heavy-duty live center. the live center will allow smooth, free rotation of the workpiece. if a power-operated tailstock is used, it should include a means of throttling the actuating- mechanism to prevent a hammer blow effect when the workpiece face contacts the drive pins of the driver; otherwise, the pins could be damaged. center hole size for proper face driver function while center hole diameter is not critical, it can adversely affect face driver operation if not taken into consideration in the selection of the proper center point for a given application.
this area of the face drive is the housing and guide for the drive pins, center pin and its compensating mechanism system. the compensating mechanism system allows the drive pins to adjust for any variation in flatness of the workpieces end. in some mechanical designs, a convex and concave washer system works with the spring-loaded or fixed-center pin to allow the system to accommodate irregularly faced workpieces. unlike a chuck or grinding dog, a face driver grips and turns the part by locating only on the face of the workpiece. with a chuck or grinding dog, the part must be removed after the first operation, reversed and rechucked before any more operations can be performed.traditional machining requires multiple operations and setups that increase costs, cycle times and reduce part quality.