An automated device for producing a closed part, commencing with an open part having a cap joined with a hinge to a body, the device comprising: a tool having a guide surface defined in an operating plane substantially orthogonal to a hinge axis; a part gripper disposed on a computer numerically controlled shuttle, the part gripper operable to: select an open part from a stream of identical open parts; engage one of: the cap; and the body, on a start point on the guide surface; slide the open part, within the operating plane from the start point to a finish point on the guide surface, to rotate the cap about the hinge axis from an open position to a closed position relative to the body; and release the closed part from the part gripper at a release station.