Abstract: A cope flask is precisely centered relative to a cope pattern by a flask displacement mechanism affixed to a cope stool which lineraly shifts the flask relative to the pattern while taking up clearance between the locator pins of the cope flask and the locator bushing in the stool. This precision centering is maintained while mold sand is poured into the flask and compacted. The cope mold comprising the flask and the hardened sand is stripped from the stool for subsequent mating with a drag mold made in a similar manner but with the drag stool having locator pins secured in its top surface and the locator bushings provided in the drag flask. As with the cope mold making procedure, the drag flask is precisely centered relative to the drag pattern by linearly moving the drag flask to take up clearance between the centering pins and the centering bushings in the drag with the displacement mechanism.