Abstract
We developed an optical machining system that fabricates steric objects automatically by stacking plastic layers by scanning a UV laser beam on liquid photopolymer. Some distortions are found along the lower side of the fabricated objects but they are only a noticeable problem of this system. Many experiments carried out under various conditions, by changing a speed of laser scan, thickness of layers, and irradiation power, revealed that the shrinkage of the photopolymer results in deformation. We propose a new hypothesis, that is, the speed of photopolymerization is the second major cause of this curious disortion.
