Abstract: The invention provides apparatus and methods for applying force to an object or workpiece. The invention has a first stationary magnet and second moveable magnet within a housing member. The magnets are arranged such that the magnets repel one another with a force related to the spacing between the magnets. The housing member is coupled to a modifying member, e.g., a motorized grinder or sharpener, with the object or workpiece disposed between the second magnet and the modifying member such that the second magnet forces the object or workpiece against the modifying element. The magnets can be electromagnets. In a preferred aspect, the object is a rotary razor head commonly used in electric razors and the invention sharpens the rotary razor head. In this aspect, the modifying member is a rotating grinding disc and anti-rotation elements prevent the razor head and magnets from rotating with the grinding element. The razor head is forced into the grinding element by the magnetic force formed by the two magnets.