傾斜ビーム回転走査法による無段差積層光造形法(設計支援手法・CAD/RP-III)

抄録

One of the major causes of poor surface finish in stereolithography is stair-stepping effect and it causes deviation between designed layers and built layers. Designed layers may be trapezoidal or rectangular, in a two dimensional view, but the available processes can only fabricate rectangular layers because of scanning and recoating limitations. This paper proposes a new stereolithography scanning mechanism that named as slant beam rotation (SBR) scanning to reduce stair-steps. An inclined beam of UV light is used to fabricate slant surfaces and for the change of build angle. The inclined beam is rotated through 360 degrees taking the point of incidence as center of rotation on the surface of resin. Based on SBR scanning scheme, experimental system has been developed to realize the feasibility of the proposed scanning method. In addition a new data format which contains information about the slant angles is proposed and termed as slant edged layer (SEL) data format. As a result of SBR scanning, the average value of surface roughness for a typical object of 400μm layer thickness changed from 18.0μm to 1.1μm. Layer thickness is one of the major reasons of longer build times and if SBR scanning is used, a build time can also be reduced to at least half of the available stereolithography systems.