Boring riser holes in a graphite mold

A method of boring a plurality of openings in a cylindrical block comprising the steps of:

• securing an indexing plate assembly to the base of a drill press such that a circular indexing plate is rotatably removable on the drill press base about a preselected axis,
• securing an extended edge of the indexing plate from rotation with an indexing plate support,
• placing a cylindrical block onto the indexing plate such that the block rotates with the indexing plate,
• drilling a first opening through the cylindrical block at a preselected angle and radial distance from a center axis of the cylindrical block,
• rotating the indexing plate with the cylindrical block through a preselected angular displacement and drilling a second opening through the block at a preselected angular displacement from the first opening and at the same radial distance from the center axis of the cylindrical block as the first opening,
• wherein the extended edge of the indexing plate is circular in shape with a plurality of guide openings therein,
• the indexing plate support has at least one support opening,
• and the indexing plate is secured from rotation by a removable locating pin passing through a support opening in the indexing plate support and an aligned guide opening in the indexing plate,
• and the indexing plate support engages at least a portion of the extended edge of the indexing plate and the indexing plate support includes an advancing mechanism whereby the indexing plate can be rotated a selected angular displacement through the indexing plate support.

A drill press assembly comprising

• a drill press table,
• a base plate secured to the drill press table, an indexing plate rotatably moveable on the base plate about a preselected axis,
• an indexing plate support securing an extended edge of the indexing plate,
• a block placed in the indexing plate such that the block rotates with the indexing plate,
• a drill press arm on a drill head supported thereon, the drill head located at a preselected location on the drill press arm in order to drill a first opening in the block at a first preselected location in the block,
• and, upon rotation of the indexing plate and the block, the drill head being able to drill a second opening in the block at a second preselected location without moving the drill head,
• and wherein the first and second openings in the block are at the same radial distance from the center point of the block,
• wherein the indexing plate is circular in shape with a plurality of guide openings in an extended edge portion of the guide plate,
• the indexing plate support has a plurality of support openings,
• and a locating pin passes through a support opening in the indexing plate support into an aligned guide opening in the indexing plate to hold the indexing plate at a preselected location on the drill press table,
• and wherein that selected support openings in the indexing plate can be aligned with selected guide openings in the indexing plate to allow a preselected number of equally spaced apart openings to be drilled in the block at a preselected radial distance from the center point of the block.