Sliding dovetail clamping system of cast components. This is a traditional system used on core boxes, typically made from stamped steel. The apeal for core boxes is that they are robust, quick, and resistant to stray sand and binders. Freeman Supply sells the stamped version, but the sizes are limited and the prices high. Cast components are easy to make. There are three components: a pair of mirrored anchor pieces, affixed; and a sliding cleat that pulls the anchor pieces tog ether. The dovetail surfaces are 15° to the mounting surface plane; the dovetails on the sli der converge at 5° per side, making an included angle of 10°. The anchor pieces can be cast complete with mounting countersinks, bedded at about 45°; but I chose to leave off the countersinks, so that the pieces can be cast on end, pressed down into a flask of sand. The opposed dovetails of the slider require casting on end, unless the pattern is cored or made to separate somehow, so I made my patterns to withdraw end-on. Note that the draft on the slider taper the opposite way from the dovetails. In mounting the anchors to the box, screw them on so the dovetails converge at ten degrees, gapped apart so the slider will end up centered when tapped on with a hammer. To keep patternmaking to a minimum, the anchors can be made by casting extra sliders and sawing them down the middle. For light service the anchors can be replace by flat head wood screws driven to leave the heads proud about 3/16 inch. I made some alternate anchors for use where the lid of the core box is too thin to reasonably accept screws through the side. These anchors wrap the corner onto the top of the lid and are screwed there.
No, the white patterns at the rear are larger size rigid polyurethane samples cast in silicone molds. The bronzes were cast from cast epoxy patterns (also cast in silicone). Standard rigid patterns, withdrawn from the sand.
