A
solid imaging apparatus is provided that includes a replaceable
cartridge containing a source of build material and an extendable and retractable flexible transport film for transporting the build material layer-by-layer from the
cartridge to the surface of a build in an
image plane. An operator using the device needs merely to remove a spent
cartridge and replace it with a fresh cartridge to continue
solid imaging virtually uninterrupted. The apparatus also includes the capability of withdrawing and inserting an imager without the operator having to perform a separate alignment step. A
brush attached to the transport film and forming part of the cartridge provides for intra-
layer removal of excess uncured build material. If desired, the apparatus can produce a fully reacted build. A
high intensity UV source cures the build between
layers. An injection molded build pad is designed to hold a build in an inverted position for improving the build. The invention also provides for tilting the build
elevator to reduce
air entrainment and for releasing the build from the
image plane.