Link system

A method of using target datum reference surfaces on fixtures for parts and on cutting machines having a cutting element for a cutting a depth of cut in the part, said method comprising:

• placing targets on the fixtures and adjusting target datum surfaces thereon to a precise dimension having a fine tolerance;
• placing a target on the machine head carrying the spindle and adjusting the position of its datum reference surface to a precise dimension relative to a target fixture datum surface;
• setting a stop on the machine to limit depth of the tool cut in accordance with the dimension and tolerance between the machine head and fixture datum reference surfaces;
• recording the tolerance at which the stop is located relative to a target;
• moving a feed slide for the machine head between spaced target datum surfaces on the fixture and determining the inclination of the feed slide;
• adjusting the feed slide relative to the machine to within a predetermined tolerance as between the pair of target datum surfaces;
• recording the tolerance to which the feed slide is adjusted;
• establishing the perpendicularity of the spindle relative to the part by using two spaced indicators on the fixture and noting differences in measurements by turning the spindle;
• adjusting the inclination of the spindle to have its perpendicularity within a tolerance range for perpendicularity;
• and
• recording the perpendicularity tolerance for later use.

An apparatus for machining parts to print tolerances at a plurality of machining stations along the line, said apparatus comprising:

• a machine having a cutting head with a movable spindle at a first cutting station;
• slide means mounting the cutting head for transverse movement during a cutting operation;
• other cutting machines at other machining stations for making cuts on the same part;
• fixtures for supporting the part during the machining of the part and movable to position the part at the respective machining stations;
• locator surfaces on the fixture to establish the parts position on the fixture during machining at the first machine;
• datum reference targets on the fixture set relative to locator surfaces on the fixture at predetermined positions and spacings so that a subsequent position of locator surfaces may be checked if parts being machined are not made to specified part tolerance;
• and
• at least one datum reference target on the cutting head for use in cooperation with datum reference targets on the fixtures to set the spindle face perpendicularity, feed slide tracking and full depth of cutting tool initially to in-process tolerances, and to serve as datum references to check positions thereof made to specified in-process tolerance.