Abstract: A method of locating a close-fitting part within a receptacle of a body, comprising: (a) providing movement of a carriage within a fixed plane, the carriage having a locator finger and part in known relative spaced relation; (b) floating the body for movement in a plane perpendicular to the fixed plane; (c) locating the receptacle by moving the carriage to effect axial motion of the locator finger at a predetermined spatial station to bring the axis of the receptacle to a fixed known location coincident with the axis of the locator finger; and (d) inserting the part into the receptacle by indexing the carriage along the fixed plane to effect axial insertion of said part into the receptacle at the predetermined spatial station. The axial movement of steps (c) and (d) are coincident within a tolerance of .+-.0.00005", and the part is preferably a sharp-edged spool valve, and the receptacle is preferably a close-fitting valve opening providing a maximum diametrical clearance of 0.0003 inches.