Abstract: A stereolithography machine is employed to solidify a pattern including a series of stacked grids forming the pattern having an outer skin and inner labyrinth and any number of gates. The hollow pattern is mounted on a central sprue through runners at the gate of the pattern. The pattern is dipped in ceramic slurry and sifted in a refractor grain in order to coat the hollow pattern. The hollow pattern is melted to form a mold.

Abstract: There is disclosed a system and method for rotationally controlling a circular structure, such as a dome, from the outer circumference of the dome. The system uses an air driven motor having a circular fixed section and a movable section. The movable section is attached to the rim of the dome and is supported by pressurized air over the fixed section. Air, or other fluid, is used to drive the movable section, and hence the dome, around the circle. The dome speed is controlled by air pressure and the position of the dome is monitored.

Abstract: There is disclosed a system and method for rotationally controlling a circular structure, such as a dome, from the outer circumference of the dome. The system uses a linear stepping motor having a circular fixed section and a movable section. The movable section is attached to the rim of the dome and is in magnetic coupled contact with the fixed section. Controllable magnetic fields induced between the movable and stationary sections cause the movable section, and hence the dome, to drive around the circular fixed section. The dome speed is controlled by the magnetic fields and the position of the dome is monitored by monitoring the position of the active magnetic fields.