This device is found in Factory Bay B of Soulforge Cathedral (second floor, W). The machine has two hatches on one side for the insertion of "source materials" and a tube at one end. It is started by a lever on the platform above the machine, which also closes the hatch doors.
The platform is often difficult to get down from, so the lever should be pulled twice with each use to eliminate the need to climb up again and open the doors.