Abstract
In order to perform the machine work with sufficient accuracy, the position of the tool tip position be measured accurately. Tool tip detectors of CCD camera type by acquisition the image of the tool are developed. This study unveils error of the tool tip position versus tool diameter and numerical aperture of illumination optical system as object of ball end mills. Telecentric illumination system and telecentric imaging system is built by optical simulation software, ray traces of ball end mill and sphere for comparison was done. Errors occurred approximately linear for tool (sphere) diameter. For the sphere case, position errors occurred in the negative direction, indicating a tendency to increasingly underestimate target object diameter relative to the original 3D model, with increasing numerical aperture. It occurred because of refraction at the surface of the sphere. For the ball end mill case, position errors occurred in the positive direction, indicating a tendency to increasingly overestimate target object diameter relative to the original 3D model, with increasing numerical aperture. However, absolute values of errors are 1/10 of the spheres. Because the section of the tool tip has V shape and not ball shape.
