熔融沉積成型(Fused Deposition Modeling, FDM)為眾多積層製造(Additive Manufacturing, AM)技術中的其中一種。FDM有著客製化等優點使其能應用於許多領域中，但本身也存在著缺點。本研究將著重於FDM之尺寸誤差缺點作改善。 直接影響尺寸誤差的決定因素在於加工路徑，亦即是沉積材料沉積的路徑。原因在於沉積材料相對於路徑點資料有著線徑之差距，而加工路徑即是模型的外型輪廓，由STL(STereoLithography)三角網格模型切層而來，且FDM為疊層的方式製造。故本研究改善尺寸誤差之主要方法，為將加工路徑作偏移，以補償線徑所造成的誤差。而加工路徑偏移的偏移量，為根據三角網格與工作平面的夾角決定。 其中本研究發展之偏移方法有兩種：等向偏移(Isotropic Offset Method, IOM)與非等向偏移(Anisotropic Offset Method, AOM)方法。其主要差別在於一個切層輪廓偏移中，IOM以等量之偏移量偏移所有輪廓之邊，而AOM則是以輪廓各自邊之不同偏移量作偏移。 本研究之實驗FDM機台為Ultimaker 3，以實心特徵與空心特徵模型驗證IOM與AOM之差別，並由Cura商用軟體進行切層處理產生之模型為對照組。實心特徵模型AOM之誤差在公差範圍內比例為81.86%，而IOM為72.08%。空心特徵模型AOM比例為89.5%，IOM為90.28%。以上公差範圍設定在±0.1mm之間，以此標準驗證之結果，在公差範圍內之比例，Cura實心特徵模型為75.59%，空心特徵模型63.89%都比AOM差。 ;Fused Deposition Modeling (FDM) is one of many Additive Manufacturing (AM). FDM has the advantages of customization so that it can be applied in many fields, but it also has its own disadvantage. This study will focus on improving the error of size for FDM. The tool path is a factor that causes the error of size directly, and also is the path which deposition material deposit. The error of size is caused since the line width within deposition material is different to the point data of path. The tool path is the silhouette of the model, sliced from the Stereolithography (STL) consisting of triangular facets. The FDM technique is layer by layer. Hence, move the tool path to compensate the error of size caused by line width is the major method in this study, and the offset amount of tool path is decided according to the angular between triangular mesh and working plane. There are two method for offsetting in this study: Isotropic Offset Method (IOM) and Anisotropic Offset Method (AOM). The main difference between IOM and AOM is that in a sliced section, IOM moves the edges of all contours by an equal offset amount, while AOM moves the edges by the different offset amount of the contour. The experimental FDM machine of this study is Ultimaker 3, the difference between IOM and AOM is verified by solid feature model and hollow feature model, and the models produced by Cura commercial software is used as the control group. The ratio of error within tolerance range of the solid feature in AOM is 81.86%, while that in IOM is 72.08%. The ratio of hollow feature model in AOM and in IOM are 89.5% and 90.28%, respectively. The above tolerance range is set between ±0.1mm. The result of the standard verification reveals that the ratio of the Cura solid feature model is 75.59% and the hollow feature model is 63.89% are worse than AOM.
