the instant invention relates to power tools . more specifically , the instant invention is a portable device for shaping , contouring and polishing the edge of a workpiece consisting of a hard material . the device includes a guide - way constructed and arranged to attach directly to the upper surface of the workpiece . a carriage is slidably supported on the guide - way for movement along the length thereof . secured to the carriage is a motor for rotation of a rotary tool . a pneumatic cylinder is provided to force the rotary tool into the workpiece with a predetermined pressure along a predetermined axis of approach . the carriage is constructed and arranged for vertical positioning and angular rotation of the rotary tool .