Basing precision of disk and bush blanks in multipoint machining

Abstract

In mass production, multipoint machining of disk and bush blanks is often employed, on the basis of multipoint mandrels. At the same time, the bases and basing systems for such machining is not considered in the relevant literature and in State Standard GOST 21495–76 [1]. Their basing is assumed to be analogous to the basing of individual blanks. However, this is clearly erroneous, not only in view of the formal aspects of the problem (which geometric elements are technological bases and how they should be repre� sented in theoretical basing systems) but in fundamen� tal respects (the basing precision for such blanks). In the present work, we analyze the bases and basing sys� tems for such blanks in multipoint parallel and serial machining, as well as the basing errors in terms of the dimensions and mutual position (lack of concentric configuration) of cylindrical surfaces. We employ the terms and concepts in [2–4].