Automation of fixture design using feature based modelling

Abstract

Fixturing is an important manufacturing activity, but there are very few hard and fast engineering principles involved in the fixture design process. Even the available limited analytical rules are not so flexible enough for the correct fixture design. Further more, there is no exact definition as to what constitutes a good fixture design. A skilled tool designer learns his trade through apprenticeship training and many years of experience. With the current decline in the number of skilled machinists, tool and die workers, there is a clear need for an increase in the level of fixture automation. The present paper describes an interactive Computer Aided Fixture Design (CAFXD) system using the Gauss Elimination Method for the design of a fixture to hold prismatic components during machining on a CNC machining centre. The Feature Based Modeller (FBM), which consists of fixturing modules, allows the user to model the component in terms of meaningful manufacturing features and help in the selection of correct location points. The mechanical analysis of the component which has been carried out in the paper will suggest the clamping details.