An additive manufacturing apparatus includes: first and second spaced apart side walls extending along a pre-defined path and defining a build chamber therebetween; one or more build units mounted for movement along the pre-defined path, the one or more build units collectively including: a powder dispenser positioned above the build chamber; an applicator configured to scrape powder dispensed into the build chamber; and a directed energy source configured to fuse the scraped powder; a moveable build platform disposed between the first and second spaced-apart side walls; and an actuator assembly connected to the build platform, the actuator assembly being configured to rotate and move the build platform continuously along a build axis to provide a spiral movement and permit a part to be built continuously in a spiral configuration.