Computer-aided manufacturing of laminated engineering materials (CAM-LEM), developed at Case Western Reserve University, is a layered-manufacturing approach utilizing automated stacking of parts laser-cut from sheet materials. This paper presents the design of a material-handling system and its integration with a modular laser-cutting system, completing the most recent version of CAM-LEM. Our material-handling system is required to: transfer individual sheets from at least three material stacks to the cutting table of the laser-cutting system; extract single-layer, laser-cut parts from the cutting table; and stack the parts onto a vertical-stack assembly, resulting in fabrication of a 3D object. Design philosophy, details, and stacking performance measurements of the constructed system are presented. It is shown that the resulting system is capable of assembling objects within a 150 mm cube with an assembly precision of approximately 0.050 mm. Further, the assembly operations are relatively fast, so that part build rates are limited primarily by the laser cutter.

Computer-aided manufacturing of laminated engineering material (CAM-LEM) is a form of solid freeform fabrication involving feeding, cutting and stacking of sheet materials to form 3D objects. To improve build rates and surface finish, it is desired to cut layers of an object from relatively thick sheets with consideration of tangent angles about each layer's perimeter. Design of the cutting system is key to the success of this approach, since speed and accuracy must be high. This paper describes the evolution of our laser-cutting system from a 5-axis design with stationary optics to a 4-axis design with articulated optics. Detailed analysis and characterization of the competing designs shows that the 4-axis design offers an improvement in both speed and precision.