Abstract: A system and method for characterizing and measuring hydrodynamic grooves made by ECM processes is disclosed. The method includes a procedure for alignment of the work piece to the measurement apparatus as well as a technique for accurately reliably measuring the erosion pattern quickly. Additionally, the invention provides a system for characterizing and measuring the erosion of these grooves.

Abstract: Embodiments of the invention generally provide a method for characterizing the surface topology of a hydrodynamic bearing used with a disc drive. In one embodiment, the invention provides a method to detect at least one hydrodynamic groove disposed on the hydrodynamic bearing. In another embodiment, the invention provides a method to measure the depth of at least one hydrodynamic groove. In still another aspect, the invention provides a method to establish a ratio between the hydrodynamic groove widths and the spacing between adjacent grooves.

Abstract: A system and method for characterizing and measuring hydrodynamic grooves made by ECM processes is disclosed. The method includes a procedure for alignment of the work piece to the measurement apparatus as well as a technique for accurately reliably measuring the erosion pattern quickly. Additionally, the invention provides a system for characterizing and measuring the erosion of these grooves.

Abstract: Embodiments of the invention generally provide a method for characterizing the surface topology of a hydrodynamic bearing used with a disc drive. In one embodiment, the invention provides a method to detect at least one hydrodynamic groove disposed on the hydrodynamic bearing. In another embodiment, the invention provides a method to measure the depth of at least one hydrodynamic groove. In still another aspect, the invention provides a method to establish a ratio between the hydrodynamic groove widths and the spacing between adjacent grooves.

Abstract: Hydraulic drilling method and apparatus in which the drilling fluid itself is utilized to control the direction in which a hole is bored in the earth. The orientation of the drill head is monitored by tilt and roll sensors, and the discharge of drilling fluid through radially or obliquely directed nozzles is controlled by poppet valves in accordance with the orientation to control the direction in which the hole is cut.