Algorithms for Multilayer Conformal Additive Manufacturing

Abstract

Despite the rapid advance of additive manufacturing technologies in recent years, methods to fully encase objects with multilayer, thick features are still undeveloped. This issue can be overcome by printing layers conformally about an object’s natural geometry, as opposed to current methods that utilize planar layering. With this mindset, two new methods are derived to generate uniformly distributed layers between initial and desired geometries in both two and three dimensions. The first method is based on variable offset curves and can only be applied to convex or star-convex geometries. The second method is based on manipulated solutions to Laplace’s equation and is applicable to all geometries. Using each method, we present examples of layer generation for several geometries of varying convexities. Results are compared, and the respective advantages and limitations of each method are discussed.

Testbed for Multilayer Conformal Additive Manufacturing

“…Davis et al [5] present two approaches for defining conformal layers between two co-registered surfaces (the build-object and desired object geometry). The first method involves the use of a variable offset curve x 1 (t; r) resulting from a parametrized curve x 0 (t) as defined…”

“…For this method to be applicable, [5] assumes (1) the build-object is a convex geometry; (2) the desired object geometry is at most star-convex; and (3) the build object centroid is positioned relative to the desired part centroid to ensure intersections of the unit normal.…”

“…In general, the AM techniques explored for conformal applications involve "direct write" technologies [6] used to produce thin features on surfaces. One primary exception is the work of Davis et al [5] that explores algorithms for deriving layers between surfaces, but does not address the transition from layering to material deposition. Related metal deposition methods involve using directed energy and welding to extend printing capabilities by increasing the total degrees of freedom (DOF) or axes used to drive the nozzle or AM tool-head.…”

“…Section 2 provides a summary of layering methods as applied to this approach using the prior work of Davis et al [5]. Section 3 presents a new approach to defining paths for filling layers leveraging a projected ring approach as opposed to more common methods inspired by space filling curves [12].…”

“…Conformal AM with multilayer, thick features can be achieved using the layering algorithms presented in [5] in conjunction with registration and manipulation methods commonly used in robotics. This paper replaces the concept of a build-bed with a largely arbitrary "build-object" referring to an application substrate with arbitrary geometry.…”