Some Aspects of Costing and Contouring Programs for Point-To-Point Numerically Controlled Machine Tools

Abstract

<p> This thesis is an investigation of some of the aspects of costing and machining that are applicable to numerically controlled (N/C) machine tools with particular reference to the facilities at McMaster University,and is divided into two sections. </p> <p> Section A is a brief discussion of the suitability of N/C for simulation methods and a review of the principles of metal cutting and the problems involved in estimating costs. A method is devised to simulate the machining of "typical" parts that have been generated by a random strategy. The results of the simulation were used to find a relationship between the geometric parameters of each part and the time required for all the machining operations to make that part, this relationship was called the "complexity factor" for the part. Sugestions for possible future extensions to the work were made.</p> <p> Section B is a feasibility study for increasing the range of use of a Moog point-to-point N/C machine to contouring, using the computer facilities available at McMaster University. It was proposed to produce a numerical control tape to machine a general oval based on a method of approximate linear interpolations using an on-line, time sharing computer terminal and a PDP "mini computer". The contouring method was tested by machining a circular groove (an oval with equal major and minor axes) and measuring the accuracy. The possibility of extending the work to other contours and three dimensional solids is discussed.</p>