Mechanical Engineering, Virginia Polytechnic Institute and State University
Abstract:
Existing layered manufacturing systems fabricate parts using a constant
build layer thickness. Hence, operators must compromise between rapid
production with large surface inaccuracies, and slow production with high
precision, by choosing between thick and thin build layers, respectively.
Adaptive layered manufacturing methods alleviate this decision by
automatically adjusting the build layer thickness to accommodate surface
geometry, thereby potentially enabling part fabrication in significantly
less time. Unfortunately, conventional adaptive layered manufacturing
techniques are often unable to realize this potential when transitioning
from the laboratory to an industrial setting. The problem is that they
apply the variable build layer thickness uniformly across each horizontal
build plane, applying the same build layer thickness to all parts and part
features across that plane even though they have different build layer
thickness needs. When this happens, the advantage of using adaptive build
layer thicknesses is lost. This thesis demonstrates how to minimize
fabrication times when implementing adaptive layered manufacturing.
Specifically, it presents a new method in which each part or individual
part feature is assigned a distinct, independent build layer thickness
according to its particular surface geometry. Additionally, this thesis
presents a calibration procedure for the Fused Deposition Modeler (FDM)
rapid prototyping system that enables accurate, adaptively sliced parts
to be physically realizable. Experimental software has been developed and
sample parts have been fabricated to demonstrate both aspects of this work.