Development of Co-Ordinate Retrieval System in CAD for Satellite Component by Shear Forming Process

Metal forming involves deforming of metal plastically into various derived shapes and sizes under the effect of externally applied forces. Flow forming is an advanced, near net shape, chipless metal forming process, which employs an incremental rotary point deformation technique for manufacturing seamless, dimensionally precise, tubular and other rotationally symmetrical products. In shear forming process deformation is carried out by combination of axial and radial forces using a set of rollers thf coordinate retrieval system using AUTO LISP for bottle neck shaped inner shell cylinder of a missile which is used for a critical space application. The experimentation consists of two stages ,i.e. Flow turning of cone with 36º included angle fromat are simultaneously moved along the length of the rotating preform. The present paper discusses on development o input Size blank of 400 x 400 x 16mm and then Spinning of cone to inner shell cylinder by spinning (3 or 4 Passes). The earlier method of development of component was a manual feeding of coordinates. This involves painstakingly measuring distances in the CAD drawing with reference to the equipment, whose axes are at an angle of 120° to one another. This process of manual retrieval of coordinates to be entered require a laborious 18hrs of operator time for every new trial. Auto Lisp, a standard feature of AutoCAD, which enables us to introduce a special command with customized output. A standard program in Auto Lisp, which gives only the end points of a polyline, was re-written to give coordinates of points at every 1 mm. This developed system brings down operator time per cycle from 18hrs to less than 15 min. and also minimizes the human error. After successful execution of the program the coordinate values thus obtained are used for the development of prototype in copper alloy and also in the development of actual material.