Adaptive rastering algorithm for freeform extrusion fabrication processes

ABSTRACT An adaptive rastering algorithm has been developed to reduce the ‘horizontal’ staircase error and/or fabrication time for freeform extrusion fabrication processes of 3D ‘solid’ parts. It analyses the geometry of each layer and changes the width of each line of the raster adaptively in order to reduce the staircase error and/or increase productivity. For each line, the maximum width that results in a staircase error smaller than a predefined threshold is determined for decreasing the fabrication time, increasing the dimensional accuracy, or both. To examine the efficacy of the proposed technique, examples are provided in which staircase errors and fabrication times are compared between uniform and adaptive rastering methods for each part. The results show a considerable improvement in accuracy and/or fabrication time for all parts studied when using the adaptive rastering algorithm.