Abstract
An approach to support learning of the geometrical tolerances using 3-dimensional (3D) models generated in the computer was proposed. In this study, a prototype system having functions that are useful to improve understanding of both of the meaning and the indication rule of the straightness of the axis was implemented. According to the user's indication, such as the width of the tolerance zone and the indicated feature, the 3D model of the axis was shown on the computer display by enlarging the geometrical deviation so that one can understand the effect of the geometrical restriction easily. The 3D model of the theoretically exact column can be overlaid in order to confirm the limit of the deviation visually. The overlaying function is also useful to find the difference of the variance between indications to the axis line and the generating line. And the system can demonstrate the behavior of fit between the axis with the straightness indication and the hole by the animation to show an example of the necessity of the straightness indication. By using these functions in the learning, it is expected that one can easily image contents of the restriction indicated by the geometrical tolerance.
