Computer-aided process dimensioning

Conventionally, working dimensions have to be given before the construction of a tolerance chart can begin. Because the method of determining the working dimensions is based on trial and error, it is tedious and time-consuming. This paper proposes a method that can generate the working dimensions automatically from the process sequences and the blueprint dimensions. The method uses a relationship matrix to represent the process sequences and a special path-tracing technique to identify the process links. A unique algorithm is developed to reduce the unknown working dimensions to a system of linear equations, which is then solved using the Gauss elimination technique. This method can either be adopted by the process planner or implemented on a microcomputer. With this method, different processing sequences based on different factors, e.g. cost, machining time, etc., can be evaluated efficiently and economically. The developed program is then tested on a practical example.